Clearance Pricing on Bosch Tankless Water Heaters

Are you looking to save $$ but demanding the quality of a Bosch Tankless Water Heater? Check out our Bosch Tankless Clearance Heaters!

Our Bosch clearance water heaters are fully warranted by the manufacturer and carry the full 15 year warranty on the heat exchanger and 5 year warranty on all parts. These clearance heaters are prior model tankless water heaters that Bosch has just recently taken out of their current water heater lineup.

We are Bosch's distributor for these clearance heaters. Just like with the current Bosch tankless water heaters, Bosch requires that the water heaters be installed by a licensed professional installer.

We also stock all of the venting and accessories that you will need to complete your installation.

Our quantities vary depending on the model you are seeking. Call us at 866.289.4652 for pricing and availability on these discounted Bosch tankless water heaters.

Hydronic Testing of Bosch Gas & Electric Tankless Water Heaters

All of the Bosch gas and electric tankless water heaters are tested from the factory before shipping.  The Bosch tankless water heaters are pressure tested for functionality, operation and leaks.  Bosch always ensures that the Bosch tankless water heaters are 100% reliable and operational when they leave manufacturing.

When Bosch has finished testing the gas & electric tankless heaters they will then place colored caps (red for electric tankless or yellow for the gas tankless) on the water inlet and outlet of the heater to prevent any residual water from damaging the insides of the unit and the box it is packed in.

Please see the image below that shows the caps on the bottom of a gas tankless water heater.

Model Numbers Pertaining to the Bosch Greenstar Combi and Straight Boilers

Below is a table describing the model numbers that pertain to the Bosch Greenstar gas-fired wall-hung boilers and combination boilers.

Z - Central heating appliance
W - DHW heating
B - Condensing technology
R - Constant temperature control
16 - Output up to 54,600 BTU/hr (16 kW)
21 - Output and DHW output up to 71,600 BTU/hr (21 kW)
28 - Output and DHW output up to 95,500 BTU/hr (28 kW)
35 - Output and DHW output up to 119,400 BTU/hr (35 kW)
42 - Output and DHW output up to 143,300 BTU/hr (42 kW)
-3 - Version
A - Fan-supported appliance
23 - Natural gas (NG) conversion to Liquid Propane (LP) comes with boiler

So if you wanted to reference model number "ZWB42-3" this would be the model number for the Bosch Combi 151 Gas-Fired Wall-Hung Boiler for space heating and domestic hot water (DHW).
Z - Central heating appliance
W - DHW heating
B - Condensing technology
42 - Output and DHW output up to 143,300 BTU/hr (42 kW)
-3 - Version

All Greenstar boilers and Combi units are fan assisted "A" and they all come preset for Natural Gas NG "23" but also come with the conversion kit for Liquid Propane LP.

Conversion:
Model #               Description
ZBR16-3             Bosch Greenstar Wall-Hung 57 Boiler
ZBR21-3             Bosch Greenstar Wall-Hung 79 Boiler
ZBR28-3             Bosch Greenstar Wall-Hung 100 Boiler
ZBR35-3             Bosch Greenstar Wall-Hung 131 Boiler
ZBR42-3             Bosch Greenstar Wall-Hung 151 Boiler
ZWB28-3            Bosch Greenstar Wall-Hung Combi 100 Boiler
ZWB35-3            Bosch Greenstar Wall-Hung Combi 131 Boiler
ZWB42-3            Bosch Greenstar Wall-Hung Combi 151 Boiler

New Bosch Greenstar 79 Gas-Fired Wall-Hung Condensing Boiler

Bosch has just introduced a new Greenstar 79 Gas-Fired Wall-Hung Condensing Boiler and it is very efficient and simple to set and operate.  Space heating boiler for connection to a hot water tank with unsurpassed performance and control. With special insulation to ensure ultra quiet operation and the exclusive keypad safety lock feature to prevent unwanted tampering with heating controls, this unit is the ideal "green" upgrade for detached & terraced houses and is also suitable for apartments.

The Greenstar 79 is simple to operate and some of the specifications include:

79,000 BTU 

AFUE rating of 95%

1" main heating connections

Can be vented with 2" or 3" PVC

3" PVC concentric vent kit available for vertical or horizontal installation

Telescopic Concentric Up and out vent kit available for horizontal installation 

The energy-savings and environmental features are:

Aluminum-Silicon heat exchanger delivers high efficiency with low temperature applications

Low NOx emissions ahead of 2012 SCAQMD regulations

Simple, intelligent control options optimize efficiency and fuel consumption

Low electrical consumption when the boiler is in standby mode

Electronic ignition

Anti-cycle and modulation control

This Greenstar 79 condensing space heating boiler can be used for either Natural Gas or Liquid Propane installations.   The heater comes preset for Natural Gas (NG), but can be converted to Liquid Propane (LP).  A gas conversion kit is included.

The Greenstar boiler comes with a temperature control FW 200 that can either be mounted to the heater or mounted to the wall beside the heater.  This module allows the heater to be set for different temperatures, zones and the time of day the heater comes on and goes off.  The FW 200 control also comes with a temperature probe that goes to the outside and detects and monitors the outside temperature and then allows the heater to remember the coldest and warmest times of the day and year.

The Greenstar condensing space heating boiler is specifically designed for space heating only but can also be used for Domestic Hot Water (DHW) when it is piped to an indirect tank and using a pump, aquastat and check valves.

New Bosch Greenstar Combi 131 Gas Fired Wall Hung Boiler

Bosch has just introduced a new Greenstar Combi 131 Gas-Fired Wall-Hung Condensing Boiler for space heating and DHW.  "Combi" (combination) unit with space heating and integrated water heating in one highly efficient, compact unit. With special insulation to ensure ultra quiet operation and the exclusive keypad safety lock feature to prevent unwanted tampering with heating controls, this unit is the ideal "green" upgrade for detached & terraced houses and is also suitable for apartments.

The Greenstar Combi 131 is simple to operate and some of the specifications include:

131.9K BTU 

AFUE rating of 95%

Delivers 3.2 GPM at 72 degree rise

3/4" Water connections

1" main heating connections

Can be vented with 2" or 3" PVC

3" PVC concentric vent kit available for vertical or horizontal installation

Telescopic Concentric Up and out vent kit available for horizontal installation 

The energy-savings and environmental features are:

Aluminum-Silicon heat exchanger delivers high efficiency with low temperature applications

Low NOx emissions ahead of 2012 SCAQMD regulations

Simple, intelligent control options optimize efficiency and fuel consumption

Low electrical consumption when the boiler is in standby mode

Electronic ignition

Anti-cycle and modulation control

These Greenstar Combi 131 condensing space heating boiler can be used for either Natural Gas or Liquid Propane installations.   The Greenstar units come preset for Natural Gas (NG), but can be converted to Liquid Propane (LP).  A gas conversion kit is included.

The Greenstar Combi units come with a temperature control FW 200 that can either be mounted to the heater or mounted to the wall beside the heater.  This module allows the heater to be set for different temperatures, zones and the time of day the heater comes on and goes off.  The FW 200 control also comes with a temperature probe that goes to the outside and detects and monitors the outside temperature and then allows the heater to remember the coldest and warmest times of the day and year.

All Greenstar Combi boilers are equipped with a high-strength stainless steel secondary exchanger and burner with double passage - ensuring consistent temperature output based on demand. The DHW hot water temperature control limit of 140°F helps prevent scale build-up within the heat exchanger.

Discrepancy in Dimensions for Bosch Therm 520HN & 520PN

There was recently a discrepancy found in the dimensions (HxDxW) for the Bosch Therm 520 series gas tankless water heaters in the product selection guide.  The discrepancy has been corrected.   Please always follow the instructions in the installation manual for a safe and proper installation of the gas tankless water heater.  The dimensions in the installation manual for the Bosch Therm 520 series heaters is correct and is:  H 25.75 x D 8.66 x W 16.73.

Service Bulletins for Bosch Therm Gas Tankless Water Heaters

Bosch has a series of service bulletins for the new model Bosch Therm tankless water heaters.  These service bulletins can be very helpful with installation questions and when having an issue to troubleshoot the heater.

Please remember to be safe when working on a gas fired appliance.  Service bulletins are helpful but you can also contact Bosch technical support for help at 800-642-3111.

Link to:
Service Bulletins for Bosch Therm Units

Replacing Older Bosch Tankless with The Bosch Therm 830ES

The Bosch Therm 830ES Non-Condensing tankless water heater is a top performance, gas tankless water heater from Bosch. This 199,000 BTU heater is designed for residential applications and can deliver hot water up to 140 degrees F with a 8.3 GPM flow rate at a 35 degree rise.  Not approved for space heating applications.

This Energy Star approved tankless water heater can produce enough hot water for 2 major applications in most homes.

The Bosch Therm 830ES heater features an electronic ignition system and can vent through either 3 inch or 4 inch diameter stainless steel vent pipe either through the side wall or up through the roof. A stainless steel concentric side-wall venting option (ESHCK-Full-Kit) is also available.

The Bosch 830ES heater comes with built-in Freeze Protection but it does not come with the 3/4" PRV and the External Water Filter.  The freeze prevention kit is designed to provide protection for the water heater down to approximately 5°F for short term conditions only. It will not protect the appliance in areas where the temperature is routinely expected to be below freezing.  The freeze prevention kit will not protect plumbing outside the appliance from freezing.

The Bosch Therm 830ES is a wholesale model heater and sold to licensed plumbers and contractors. The new Bosch Therm 830ES is a close replacement for older models such as the Bosch 250SX/250SXO,  635ES/635ESO and the 2400E.  Please be aware the 830ES is 7" taller, 2.375" wider and 2.75" deeper than the previous models. The Bosch 830ES is a direct replacement for the Bosch 2400ES.  For outdoor installations the Bosch 830ES would require the BTOK Outdoor Kit.

The Bosch Therm 830ES comes with a limited 15 year warranty on the heat exchanger and 5 years on all other parts.  Service and labor costs are not covered.

Measuring Gas Pressure using a Manometer

A manometer is referred to as a pressure measuring instrument, usually limited to measuring pressures near to atmospheric. The term manometer is often used to refer specifically to liquid column hydro-static instruments. Most of the more common manometers measure the pressure in inches of water column.  There are many different types of manometers for measuring gas pressure but they all measure the static load pressure and the dynamic pressure.  There are digital manometers of all kinds but the most common and easiest to use is the water column manometer.

Digital Manometer

Static pressure is uniform in all directions, so pressure measurements are independent of direction in an immovable (static) fluid (static pressure basically refers to the gas pressure within the Bosch tankless water heater when the heater is NOT in operation). Flow, however, applies additional pressure on surfaces perpendicular to the flow direction, while having little impact on surfaces parallel to the flow direction. This directional component of pressure in a moving (dynamic) fluid is called dynamic pressure (dynamic pressure is the gas pressure when the Bosch tankless water heater is in operation). 

Bosch gas tankless water heaters all have some type of inlet pressure tap or measuring port for measuring the gas pressure either for natural gas or liquid propane gas.  Please refer to the measuring gas pressure section for each individual Bosch gas tankless water heater.  The amount of gas flow and pressure to the tankless water heater is dependent upon the size, type and length of the gas line itself.  Always try to use the largest size possible and refer to the installation gas line sizing chart in the manual for the tankless water heater.

New 95% AFUE Rating for Bosch Greenstar Gas Fired Wall Hung Boilers

Bosch Thermotechnology has recently announced that the Bosch Greenstar models have been tested and certified by AHRI with a 95% AFUE rating. The wall mounted gas fired condensing boilers feature the best of German engineering, designed for easy service and are backed with the best warranty in the industry. The Greenstar is available in both heat only and combi models ranging from 57-151 MBH.  Available for Natural Gas or LP - one of these boilers will be a great fit for your application.

The Bosch Greenstar boilers are certified ENERGY STAR products, and with the AFUE rating of 95% they are eligible for the $150 Federal Tax credit for natural gas, propane, or oil furnace or hot water boiler. These boilers are also eligible for many state, local and utility rebates, such as Gas Networks in Massachusetts and Philadelphia Gas Works. Visit the DSIRE web site to find rebates in your area.


Haven't installed a Bosch Greenstar boiler? Now is a great time to buy with excellent rebates for your customers and for you - the Bosch Greenstar models are eligible for a $100 contractor rebate through the Bosch Thermotechnology Summer Sizzler Program which runs until September 15. View these products in the AHRI directory.  Please note the $100 contractor rebate is done through Bosch Thermotechnology and not through Global Protankless Supply.  Please call Global Protankless Supply for contractor pricing on units and accessories.

Bosch ProTankless 425PN Heat Exchanger

The Bosch ProTankless 425PN Heat Exchanger Part 8705406386 (87054063860, 8-705-406-386-0) is the current replacement heat exchanger for allBosch ProTankless 425PN tankless water heaters.

Please note that the original heat exhanger for all Bosch ProTankless 425PN tankless water heaters was 8705406275 (87054062750, 8-705-406-275-0). This part is now obsolete and has been replaced by the 8705406386 heat exchanger.

Replacement Heat Exchanger for Bosch 830ES/940ES/940ESO and Evolution 500

The Bosch 940ES, 940ESO, 830ES and the Bosch Evolution 500 Heat Exchanger Part 8705406422 is the replacement heat exchanger for all Bosch Therm 940ES, 940ESO, 830ES and the Bosch Evolution 500 tankless water heaters.

This part is also the replacement Heat Exchanger for the Bosch Aquastar 2400ES and 2700ES tankless water heaters.

Bosch Therm External Water Filter

The Bosch External Water Filter (8703305356) replaces the internal water filter that comes with the heater. Having the water filter external means it is located under the Bosch Therm tankless water heater and is therefore easy to access and clean out. Odds are that if you do not install the external water filter then the internal water filter will not get regularly cleaned out as you would have to open the cover and remove the control board to get to the internal water filter, which is not very convenient.  It is recommended to clean the filter screen at least once a year for periodic maintenance.

The Bosch Therm External Water Filter is designed to work with the following Bosch Therm Tankless Water Heaters: C 1210 ESC, GWH C 920 ESC, C 1210 ES, GWH C 920 ES, C 1050 ES, GWH C 800 ES, C 950 ES, 940ES, 940ESO, GWH 715 ES, and 830ES.

This accessory is not included with these heaters and is highly recommended.

The Bosch External Water Filter is included with the Bosch Integra 500 and Bosch Evolution 500 water heaters.

The Bosch External Water Filter is NOT compatible with the new Bosch Greentherm C950ES and Greentherm C1050ES tankless water heaters.

Replacement filter screens part 8700507059 are available for the Bosch External water filter.  Please call us at 866-289-4652

Webstone Isolation Valve Set #44443WPR

The Webstone Isolator EXP E2 Isolation Valve Kit #44443WPR (Lead-Free) for All Bosch Gas Tankless Water Heaters comes with separate hot and cold isolation valves and a Pressure Relief Valve. The NEW Webstone isolation valve set #44443WPR replaces the older set of 44443PR.  Easy two-step installation of your tankless water heater with unsurpassed safety, features and benefits. This is a complete inlet/outlet valve system that provides everything you need for a secure installation, including full port testing and flushing of the system with easy-to-install union connections.

Convenient two-step color coded union connections.

Easy quarter turn ball valve operation

Full port throughout entire valve body

Individually controlled full port drain outlet

Ready to use for flushing or descaling  (Please see the Whitlam Descale Kit)

3/4" outlet for pressure relief valve

1/2" water supply adapters included (except when purchased with the 3/4" Bosch C1210ES/C1050ES/940ES/800ES heaters as they are not needed)

Heavy forged brass construction

Conforms to NSF 61-9

Allows for one man full diagnostic testing of heater unit

This product is intended for use with all of our indoor and outdoor tankless water heaters.

The Webstone 44443WPR Isolation valves are a set of Hot & Cold Full Port Forged Brass Ball Valves w/ Hi_Flow Hose Drains & Pressure Relief Valve Outlet 3/4" IPS Union x 3/4" IPS (500 WOG) & PRESSURE RELIEF VALVE (150 PSI/200K BTU) ISO 9001.

Descaling Bosch Gas Tankless Water Heaters

All of the Bosch gas tankless water heaters both in natural gas (NG) and Liquid Propane (LP) should be descaled now and then on a periodic basis depending on the quality of the water in your area.  Some towns have low mineral content while others are very hard.  Scale is basically mineral deposits in the water that pass through the copper tubing of the heat exchanger and after heating up they stick to the insides of the copper piping and over long periods of time will restrict the flow of water through the heat exchanger causing issues and overheating. 

Global Pro Tankless Supply sells a Flow-Aide Descaling Kit that allows the user to flush the Bosch tankless water heater with not much work involved and eliminates the scale built up in the heater.

The Flow-Aide Descaler Kit comes with everything you need to quickly dissolve water scale, lime, rust, and other water formed deposits, restoring efficiency to all Bosch gas tankless water heaters.  This descaling kit will also work for all other gas tankless water heaters, boilers, etc.

Flow Aide System Descaler is a non-toxic concentrate which is certified to NSF/ANSI 60 for use as a cleaner in potable water systems. Flow-Aide is the perfect descaling solution to keep your Tankless Water Heater in good operation. Combining Flow-Aide with one of our Isolation Valve Kits (Service Valves) will make the descaling process quick and easy!

Flow-Aide is: Non-Corrosive, Non-Toxic, Fully Biodegradable*, Safe to Handle, Zero V.O.C.

IMPROVE EQUIPMENT EFFICIENCY: Water scale deposits are a significant cause of heat transfer loss, along with the subsequent increase in energy costs. In fact, even a thin layer of scale (1/32") can cause a 30% increase in the cost to operate that piece of equipment. Keeping the heating passages free of mineral deposits significantly improves efficiency, conserves energy, extends the useful life of the equipment, and saves you time & money.

The Flow-Aide Descaling Kit includes the following:

1 - 3.5 Gallon Bucket
1 - 350 GPH Pump
2 - 5 Foot Rubber Hoses
1 - Quart Flow-Aide

There is also the Flow-Aide Descaling Kit PLUS which includes the Isolation Valve Kit (Service Valves).  We also sell additional quarts and gallons of the Flow-Aide Solution.

 

Bosch Therm 520HN NG & LP Tankless Water Heater

The new Bosch Therm 520HN comes set for either NG (Natural Gas) or LP (Liquid Propane).  The 520HN has a hydro ignition and is a naturally drafting heater and requires no power to operate.  This unit is basically for 1 major application at a time such as 1 shower at a time.  The Bosch 520 HN Needs to be vented vertically with a 5" B-vent up through the roof for a minimum of 6' to the raincap.  If the heater has to be vented out the sidewall then you must use the AQ4 Powervent kit and this kit would require 110V power.  The gas connection at the bottom of the heater is a standard 3/4" connection.

The new Bosch Therm 520HN is a direct replacement for many of the older model heaters.  Below is a list of the units that the 520HN would replace.  Please keep in mind to always be aware of gas line sizing and the length of the gas line run.

The Bosch Therm 520HN could replace:

Bosch 1600P or 1600H: (If either one of these units was vented horizontally out the sidewall with the AQ4 powervent kit then that same AQ4 powervent kit can be used for the new Bosch Therm 520HN)

Bosch Aquastar 125B, 125X, 125HX, 425PN or the 425HN: (If any of these units was vented horizontally out the sidewall with the AQ1 powervent kit then that AQ1 powervent kit WILL NOT work for the new Bosch Therm 520HN.  You would need to install the new AQ4 powervent kit for the new Bosch Therm 520HN)

ELM Le Blanc 170VP or 125VP:  (If either one of these units was vented horizontally out the sidewall with the AQ1 powervent kit then that AQ1 powervent kit WILL NOT work for the new Bosch Therm 520HN.  You would need to install the new AQ4 powervent kit for the new Bosch Therm 520HN)

The Bosch Therm 520HN is a direct replacement for the older tankless water heaters listed above but you still always want to make sure and refer to the installation manual and follow the gas line sizing chart and venting requirements.  Please also refer to local code for all other restrictions and approvals.

Bosch Therm 520PN NG & LP Tankless Water Heater

The new Bosch Therm 520PN comes set for either NG (Natural Gas) or LP (Liquid Propane).  The 520PN has a standing pilot and is a naturally drafting heater and requires no power to operate.  This unit is basically for 1 major application at a time such as 1 shower at a time.  The Bosch 520 PN Needs to be vented vertically with a 5" B-vent up through the roof for a minimum of 6' to the raincap.  If the heater has to be vented out the sidewall then you must use the AQ4 Powervent kit and this kit would require 110V power.  The gas connection at the bottom of the heater is a standard 3/4" connection.

The new Bosch Therm 520PN is a direct replacement for many of the older model heaters.  Below is a list of the units that the 520PN would replace.  Please keep in mind to always be aware of gas line sizing and the length of the gas line run.

The Bosch Therm 520PN could replace:

Bosch 1600P or 1600H: (If either one of these units was vented horizontally out the sidewall with the AQ4 powervent kit then that same AQ4 powervent kit can be used for the new Bosch Therm 520PN)

Bosch Aquastar 125B, 125X, 125HX, 425PN or the 425HN: (If any of these units was vented horizontally out the sidewall with the AQ1 powervent kit then that AQ1 powervent kit WILL NOT work for the new Bosch Therm 520PN.  You would need to install the new AQ4 powervent kit for the new Bosch Therm 520PN)

ELM Le Blanc 170VP or 125VP:  (If either one of these units was vented horizontally out the sidewall with the AQ1 powervent kit then that AQ1 powervent kit WILL NOT work for the new Bosch Therm 520PN.  You would need to install the new AQ4 powervent kit for the new Bosch Therm 520PN)

The Bosch Therm 520PN is a direct replacement for the older tankless water heaters listed above but you still always want to make sure and refer to the installation manual and follow the gas line sizing chart and venting requirements.  Please also refer to local code for all other restrictions and approvals.

New Greentherm PP Concentric up and out vent kit

New for the Bosch Greentherm C 950 ES & C 1050 ES is the polypropylene concentric up-and-out venting kit consisting of the appliance adapter, a 90° elbow, and a termination. This is the simplest and quickest venting option possible for a condensing tankless unit. The outer metal pipe and the inner polypropylene pipe make it both lightweight and rigid. The termination is telescopic to allow for varying wall thicknesses.

This new PP concentric up and out vent kit is approved for the New Green Therm C950ES & C1050ES tankless water heaters.  The PP concentric up and out vent kit is also approved for the Bosch Therm C950ES & C1050ES.  

Before attaching the appliance adapter to the top of the heater, a second metal plate comes with the kit and would cover the other intake air hole.  Then you would want to remove the exhaust collar from the top middle of the heater and then attach the appliance adapter as this will enable the heater to exhaust to the outside and also take its combustion air down the outer side of the same hole.

Bosch Greentherm PP concentric up and out vent kit (7738003210)

The Greentherm models C 950 ES & C1050ES are also approved for PP twin-pipe venting systems. Availability of generic PP vent pipe has increased and systems are becoming more popular due to ease of installation.  The twin pipe installation would be used if the customer needed to go out a different area out the sidewall or through the roof and would need to take the combustion air from the outside also.



PP Common Venting Systems for Cascaded Units

New for the Greentherm C 950 ES and C 1050 ES, and the Therm C 1210 ES and C 1210 ESC, is a common venting system of polypropylene pipe for up to four appliances. Offered in either a side by side or back to back configuration, the kits allow for a single vent pipe for all units. Combustion air must be taken from the room for multiple units common vented.  A 3" PVC 90 degree elbow would want to be placed on either the left or right air intake hole for the combustion air to keep anything from falling into the heater.  This is mandatory for commercial applications, with multiple units installed and that the multiple units are common vented with either the side by side or back to back venting option.  All other applications such as residential, single units, etc. must take the combustion air from the outside using 3" PVC or 3" dia PP pipe.  Please refer to the installation manual for the Bosch tankless water heater for the combustion air requirements for the heater. 

Side by side with horizontal termination (left),

back to back with vertical termination (right)



The new polypropylene pipe (PP) common venting system features different kits for cascaded units of 2, 3 or 4 units.  Kits would have to be ordered as needed:

Kit A - side by side, units #1 & #2 (2 heaters) (7736501100)

Kit B - side by side, units #3 & #4 (1 heater) (7736501254)

Kit C - back to back, units #1 & #2 (2 heaters) (7736501253)

Kit D - Extension back to back, units #3 & #4 (2 heaters) (7736501252)

There are also additional 6" diameter PP venting pieces available.  There are additional:

Horizontal Termination Dia 6"  (7736501117)

Vertical Termination Dia 6"  (7736501119)

Extension rigid straight pipe 20" Dia 6"  (7736501137)

Extension rigid straight pipe 40" Dia 6"  (7736501135)

Extension rigid straight pipe 80" Dia 6"  (7736501133)

Rigid 90 degree elbow Dia 6"  (7736501132)

For example:

Say you were common venting and cascading 4 units side by side and venting up through the roof then you would want 1 - Kit A for units #1 & #2, 1 - Kit B for unit #3 and then 1 - Kit B for unit #4.  You would also then need 1 - 90 degree elbow, how many extra feet of extension straight pipe and then the vertical termination.

New Bosch Greentherm C 1050 ES Condensing Tankless Water Heater

The New Bosch Greentherm C 1050 ES Condensing tankless water heater is a top performance, fully condensing gas tankless water heater from Bosch. This 199,000 BTU heater is designed for residential or commercial applications and can deliver hot water up to 140 degrees F with a 10.5 GPM flow rate.  Not approved for space heating applications.

This Energy Star approved tankless water heater can produce enough hot water for 2-3 major applications in most homes or is good for most commercial applications.  The Greentherm C 1050 ES is now 94% energy efficient.

Unlike traditional non-condensing models, condensing technology captures heat from the exhaust gas and uses it to preheat the incoming cold water. This increases efficiency and reduces emissions -- well ahead of the 2012 Low NOX emissions standards set by SCAQMD (California -- South Coast Air Quality Management District).  The Greentherm C1050ES now has NSF Certification (National Sanitation Foundation) for commercial kitchens.  The Bosch Green Therm C1050ES now has an added bypass tube connecting the cold and hot water lines inside the unit so the heater can mix a little cold water with the hot to alleviate and fluctuations and maintain a more stable temperature.  Standard now also are three NTC temperature sensors. With a new sensor immediately after the HEX, the Greentherm achieves benchmark temperature control. The NTCs are no longer clipped on, but rather installed into the inlet and outlet pipes.

The Bosch Greentherm C 1050 ES features an electronic ignition system and can vent through either 3 inch or 4 inch diameter PVC vent pipe either through the side wall or up through the roof.  The Greentherm C950ES now takes a new concentric venting system and attaches right to the top of the heater and takes its intake air and exhaust out through one hole to the outside.  The Greentherm C1050ES can now be cascaded together with up to 4 units and they can all vent into one pipe using a special venting kit to the outside.  Installation can be done venting up to 4 units together into the one pipe having the heaters mounted side by side or back to back.  The combustion air for the units will need to be taken from the inside of the building.

The Bosch Greentherm C 1050 ES comes with built in freeze protection.  The Greentherm C1050ES also comes with an external water filter screen.  The Bosch Green Therm C1050ES does not come with a 3/4" pressure relief valve, this is an accessory that would have to be ordered separately.

The freeze prevention kit is designed to provide protection for the water heater down to approximately 5°F for short term conditions only. It will not protect the appliance in areas where the temperature is routinely expected to be below freezing.  The freeze prevention kit will not protect plumbing outside the appliance from freezing.

The Bosch Greentherm C 1050 ES comes with a limited 15 year warranty on the heat exchanger and 5 years on all other parts.  Service and labor costs are not covered.

New Bosch Greentherm C 950 ES Condensing Tankless Water Heater

The New Bosch Greentherm C 950 ES Condensing tankless water heater is a top performance, fully condensing gas tankless water heater from Bosch. This 175,000 BTU heater is designed for residential or commercial applications and can deliver hot water up to 140 degrees F with a 9.2 GPM flow rate.  Not approved for space heating applications.

This Energy Star approved tankless water heater can produce enough hot water for 2 major applications in most homes.  The Greentherm C 950 ES is now 93% energy efficient.

Unlike traditional non-condensing models, condensing technology captures heat from the exhaust gas and uses it to preheat the incoming cold water. This increases efficiency and reduces emissions -- well ahead of the 2012 Low NOX emissions standards set by SCAQMD (California -- South Coast Air Quality Management District).  The Greentherm C950ES now has NSF Certification (National Sanitation Foundation) for commercial kitchens.  The Bosch Green Therm C950ES now has an added bypass tube connecting the cold and hot water lines inside the unit so the heater can mix a little cold water with the hot to alleviate and fluctuations and maintan a more stable temperature.  Standard now also are three NTC temperature sensors. With a new sensor immediately after the HEX, the Greentherm achieves benchmark temperature control. The NTCs are no longer clipped on, but rather installed into the inlet and outlet pipes.

The Bosch Greentherm C 950 ES features an electronic ignition system and can vent through either 3 inch or 4 inch diameter PVC vent pipe either through the side wall or up through the roof.  The Greentherm C950ES now takes a new concentric venting system and attaches right to the top of the heater and takes its intake air and exhaust out through one hole to the outside.  The Greentherm C950ES can now be cascaded together with up to 4 units and they can all vent into one pipe using a special venting kit to the outside.  Installation can be done venting up to 4 units together into the one pipe having the heaters mounted side by side or back to back.  The combustion air for the units will need to be taken from the inside of the building.

The Bosch Greentherm C 950 ES comes with builtin freeze protection.  The Greentherm 950ES also comes with an external water filter screen.  The Bosch Greentherm C950ES does not come with a 3/4" pressure relief valve, this is an accessory that would have to be ordered seperately.

The freeze prevention kit is designed to provide protection for the water heater down to approximately 5°F for short term conditions only. It will not protect the appliance in areas where the temperature is routinely expected to be below freezing.  The freeze prevention kit will not protect plumbing outside the appliance from freezing.

The Bosch Greentherm C 950 ES comes with a limited 15 year warranty on the heat exchanger and 5 years on all other parts.  Service and labor costs are not covered.

New Bosch Tronic 3000T ES Mini-Tank Water Heaters

Bosch has rebranded the Ariston Pro Ti line of electric mini-tank water heaters. They are now labeled as Bosch Tronic 3000T ES Electric Mini-tank Water Heaters.

The old Ariston Pro Ti models GL2.5Ti & GL2.5TiS are now the Bosch ES 2.5.
The old Ariston Pro Ti models GL4Ti & GL4TiS are now the Bosch ES 4 .
The old Ariston Pro Ti models GL8Ti & GL8TiS are now the Bosch ES 8.

The new Bosch ES2.5, ES4 and ES8 electric mini-tank water heaters are the same size as the mini-tanks that each replaces.  The replacement parts for the new Bosch ES2.5, ES4 and ES8 are different now and will not work for the older Ariston GL2.5Ti, GL4Ti or the GL8Ti.

*  Please note that the new Bosch ES4 is not a direct replacement for the retail model Ariston GL4 as the Bosch ES4 is 13 1/2" in depth and the retail Ariston GL4 is 12 1/4" deep.

The new Bosch ES2.5, ES4 and ES8 have many new improvements since they have been upgraded. The mini tanks have a new temperature adjustment knob on the front of the unit to raise and lower the temperature from 65 Deg F to 145 Deg F. On the older models you would have to remove the grey oval cover to access the temperature control knob.

The Bosch ES2.5, ES4 and ES8 models have a new improved thermostat that features a new sensing probe that is attached to the thermostat and inserts into the cavity of the new heating element so the heater can adjust temperatures quicker and maintain a more consistent heat.

The new model ES8 now has to be hard wired to a plug for 110V.  Global Protankless Supply carries 6' cords for the Bosch ES8 heater.

See our web site at www.prowaterheatersupply.com for all the details.

Steve

Venting requirement for Bosch AQ4 Powervent kit

The Bosch AQ4 Powervent Kit with built-in freeze protection is designed for the Bosch Therm 520HN (Hydro Ignition) and 520PN (Pilot) tankless water heaters. This accessory allows the Bosch 520HN and 520PN tankless heaters to vent horizontally out the sidewall of the home.  The AQ4 does require power to operate and operates on 120V and comes with a 3' cord to plug into the outlet.  

  The AQ4 is a power vent kit and will allow a horizontal vent run of up to 25 feet with one elbow (subtract 5 feet for every elbow). This kit includes the power vent motor.  There is also a vent hood with damper that gets mounted on the outside of the home and this built in flapper prevents the cold air from coming in when the heater is not in use.  Please make sure to refer to the installation manual and that the hood is properly installed so that the flapper stays closed all the way when not in use.  

The AQ4 powervent kit comes with a 5" to 4" reducer. This reducer fits right on top of the heater and then you would use 4" type B, C or stainless steel AL29-4C venting (not included) to go to the powervent motor.  There is a minimum of 2 feet of straight pipe required between the reducer and the blower motor.  Any venting (if needed) "after" the powervent motor must be 4" sealed stainless steel AL29-4C.  The Blower motor should be placed right at the opening where the termination hood with damper is to be installed on the sidewall of the home.

The AQ4 powervent kit is activated by a flow switch and gets attached to the cold water pipe on the right side of the unit just before it goes into the heat exchanger. 

The blower motor for the AQ4 has a new design and includes a delay setting that goes from #1 - #5 and this lets the installer set the blower motor so that when it senses flow it can be delayed for 1 - 5 seconds before the blower comes on.  This will help to ensure the pilot and burners light without getting sucked out by the blower motor. 

There is also a built in safety spill switch that gets attached to the tankless water heater and this will detect high temperatures from any flue gases in the case the blower motor does not activate and will shut the unit completely down.

$$ Special Sale on Bosch Vent Kits $$

We are pleased to announce a *very* special sale on all Bosch vertical and side-wall vent kits due to our large overstock position! We absolutely guarantee the lowest pricing on our vent kits and we will be happy to beat our competitor's pricing on any of the Bosch vent kits listed below!

We sell the AQ3ES Side-wall vent kit for the Bosch 940ES, 830ES, Evolution 500, 2700ES and 2400ES tankless water heaters. This is a 3" Category III stainless steel vent kit that contains all of the 3" venting parts needed to exhaust one of the above-mentioned tankless water heaters by going up and directly out the side wall.

We also carry our own AQ3ESPLUS kit which adds a set of WebStone 44443PR Isolation Valves and an 18" Auto-reset GFCI to the standard AQ3ES horizontal vent kit.

For those customers who are venting out a side wall that is perpendicular to the wall on which the Bosch tankless water heater is installed, we do offer the ESHCK-FULL-KIT -- a 3" Category III stainless steel concentric vent kit. This kit comes with the ESHCK concentric piece along with a 3" x 90 degree elbow, a 3" x 3' pipe and a 3" termination tee.

We carry the ES VVT through-the-roof vent kit for the Bosch 940ES, 830ES, Evolution 500, 2700ES and 2400ES tankless water heaters. This vertical vent kit contains all of the 3" Category III stainless steel venting parts needed to vent up through the roof except for the straight pipe, which is sold separately in pieces ranging in length from 6" up to 5'.

We also are the exclusive distributor for the ES VVT STEEP vent kit. In this kit we swap out the standard Adjustable Roof Flashing contained in the ESVVT vent kit for a Steep Roof Flashing at no extra charge.

We are the exclusive distributor for the AQ5EF side-wall vent kit for the Bosch 660EF tankless water heaters. This kit contains the true 2SVSWB03 Adaptor which you can only get through our company. The AQ5EF horizontal vent kit will also work with the Noritz NR-66 tankless water heater.

Looking to vent your Bosch 660EF or Noritz NR-66 through the roof? Just add the 2SVSWB03 Adaptor to either the ESVVT or ESVVT-STEEP vent kit!

Lastly, we carry the H/P VVT vertical vent kit for the Bosch 520PN, 520HN, 1600P, 1600H, GWH 425PN and certain 425HN tankless water heaters. (We also sell the AQ4 side-wall power vent kit for these same six heaters, but we are not overstocked on this part.)

The following vent kits are always in stock, but are not a part of our special sale pricing: the AQOK, BTOK and PTOK Bosch Outdoor Vent Kits and the Bosch Therm Concentric Vent Kit (196016). This latter concentric vent kit is made of PVC and is used only for the Bosch condensing tankless water heaters that are efficient enough to lower the exhaust temperature to a point where it is safe to vent through PVC.