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.