Replacement Parts for Bosch Greentherm C950 ES

Global Protankless Supply is now carrying the full line of Bosch replacement parts for the Bosch Greentherm C950ES.  Below is a list of some of the parts we carry in stock. 

Heat Exchanger: #87387040260 (Also known as: 8 738 704 026 0)
Main Burner: #87081206990 (Also known as: 8 708 120 699 0)
Water Valve w/ Engine: #87085050230 (Also known as: 8 708 505 023 0)
Gas Valve: #87070210190 (Also known as: 8 707 021 019 0)
Control Unit: #87387083890 (Also known as: 8 738 708 389 0)
Primary Fan: #87072040710 (Also known as: 8 707 204 071 0)
Secondary Fan LP: #87072040740 (Also known as: 8 707 204 074 0)
Secondary Fan NG: #87072040720 (Also known as: 8 707 204 072 0)
Condensing Heat Exchanger: #87057001610 (Also known as: 8 705 700 161 0)
Hydraulic Block: #87387041630 (Also known as: 8 738 704 163 0)
Freeze Prevention Kit: #7709003665 (Also known as: 7 709 003 665)

Please call Global Protankless Supply at 866-289-4652 for further questions or to order a part for the Bosch Greentherm C950 ES.

Venting for Bosch Greentherm C950ES/C1050ES Tankless Water Heaters

This is to explain the venting requirements for the Bosch Greentherm C950ES and Greentherm C1050ES tankless water heaters.  The Bosch Greentherm C950ES and C1050ES are direct vent units and can vent out the sidewall of the home or up through the roof.  The Greentherm units cannot be vented into an existing chimney unless there is nothing else venting into the chimney and that the vent pipe runs all the way up the chimney to a specified rain cap.

The Bosch Greentherm C950ES and C1050ES models can be vented with PVC, CPVC, PP and ABS.  The Greentherm units can be vented with 2", 3" or 4" diameter material. Below are the distances of the length of the exhaust runs.  Please refer to the installation manual for restrictions and clearances.

For further questions on venting and combustion air requirements please refer to the installation manual that comes with the unit or please call Global Pro Tankless Supply at 866-289-4652.

Replacement Heat Exchangers Now on Global Protankless Supply

Global Protankless Supply is now carrying the replacement heat exchangers for all the Bosch gas tankless water heaters.  The heat exchangers are made of high quality copper. Below is a list of all the heat exchangers and their current part numbers.  Older part numbers are also listed as part numbers have changed over the years.

Bosch Therm C1210ES / C1210ESC Heat Exchanger Part 8705406419 (87054064190 or 8-705-406-419-0).  This part is also the replacement Heat Exchanger for the older Bosch ProTankless 920ES and 920ESC condensing tankless water heaters.

Bosch Greentherm C1050ES-LP / C950ES-LP (Liquid Propane) Heat Exchanger Part 8738704026 (87387040260 or 8-738-704-026-0).

Bosch Greentherm C1050ES-NG / C950ES-NG (Natural Gas) Heat Exchanger Part 8738704117 (87387041170 or 8-738-704-117-0).

Bosch Therm C1050ES-LP / C950ES-LP (Liquid Propane) Heat Exchanger Part 8705406421 (87054064210 or 8-705-406-421-0).

Bosch Therm C1050ES-NG / C950ES-NG (Natural Gas) Heat Exchanger Part 8738721270 (87387212700 or 8-738-721-270-0).

Bosch Therm 940ES / 830ES Heat Exchanger Part 8738701985 (87387019850 or 8-738-701-985-0). This part is also the replacement Heat Exchanger for the Therm 940ESO, Bosch ProTankless 715ES, Bosch AquaStar 2700ES and 2400ES and the Bosch Evolution 500.  Older part numbers were 8705406422, 87054064220, 8-705-406-422-0, 8705406356, 87054063560, 8-705-406-356-0.

Bosch ProTankless 635ES / 635ESO Heat Exchanger Part 8705406285 (87054062850 or 8-705-406-285-0).  This part is also the replacement Heat Exchanger for the Bosch AquaStar 2400E, 2400EO, 250SX and 250SXO tankless water heaters.

Bosch Therm 520 Heat Exchanger Part 8705406386 (87054063860 or 8-705-406-386-0).  The Bosch Therm 520 Heat Exchanger Part 8705406386 is the replacement heat exchanger for all Bosch Therm 520PN and 520HN tankless water heaters and for all Bosch ProTankless 425PN and certain Bosch ProTankless 425HN (with serial numbers starting 686 and higher) tankless water heaters. It is also the replacement heat exchanger for all Bosch AquaStar 1600P and 1600H tankless water heaters. This heat exchanger replaces the obsolete 8705406275 (87054062750, 8-705-406-275-0) heat exchanger.

Bosch ProTankless 425 Heat Exchanger Part 8705406380 (87054063800 or 8-705-406-380-0).  The Bosch 425 Heat Exchanger is the replacement heat exchanger for the following Bosch ProTankless water heaters: 425EF, 425HN (with serial numbers starting 685 and lower) and 425HNO and the following Bosch AquaStar tankless water heaters: 125B, 125BO, 125BL, 125X, 125HX, 125FX.  This heat exchanger will also work with the following Bosch WR400 series tankless water heaters: WR400-1KV1P23S3100, W400KD5 P23S3100T2, WR400-3K V1B23S3100, WR400-7K V1G23S3195, WR430-3K VM1E23S3190 and WR430-3K VM1E23S3195.  Older part numbers were 8705406235, 87054062350, 8-705-406-235-0.

Bosch Greentherm C1050ES & C950ES Venting Limitations

The Bosch Greentherm C1050ES and the Bosch Greentherm C950ES gas tankless water heaters have minimum and maximum venting lengths for the exhaust and intake air.  Please review the specifications below for the two heaters and the size, material and lengths that can be used.

Vent options
The Greentherm C1050ES & C950ES must comply with the following material for exhaust and intake air.

PP common vent
PP twin pipe
PVC schedule 40 ANSI/ASTM D1785
PVC-DWV ANSI/ASTM D2665
CPVC schedule 40 ANSI/ASTM F441
ABS-DWV schedule ANSI/ASTM D2661

The Greentherm C1050ES & C950ES have many different ways they can vent such as horizontal or vertical and can use different types of material for venting and intake air.  There is the Polypropylene up and out concentric vent kit, Polypropylene common vent system if you are cascading more than one unit and up to 4 units, PVC Concentric vent kit, you can do a twin pipe PVC vent, etc.

Maximum vent lengths for exhaust, intake air and use of elbows  for the Greentherm C1050ES & C950ES are listed below:

Installing the Bosch Therm High Temperature Kit #7736500074

The Bosch Therm High Temperature Kit (7736500074) allows the maximum temperature of the Bosch tankless water heater to be raised from its normal maximum of 140 degrees F up to 180 degrees F.

The Bosch Therm High Temperature Kit is designed to work with the following Bosch tankless water heaters:  Greentherm C1050ES, Therm C10505ES, Greentherm C950ES, Therm C950ES, C800ES, Integra 500, 940ES, 940ESO, Evolution 500 and 830ES.

The Bosch Therm High Temperature Kit is not designed to work with the Bosch Therm C1210ESC or the C1210ES.

The Bosch Therm High Temperature Kit is bascially some instructions and a couple Jumpers.  The installation of the kit is very easy.  There are 2 small jumpers that will be inserted on the control board in the Bosch tankless water heater.

Installing the Bosch Therm High Temperature Kit:
*Make sure power to the unit is TURNED OFF!
1.  First remove the front cover of the heater.
2.  Then remove the screws holding the control unit on the bottom of the heater.
3.  Once the control unit is detached then you can access the back of the control unit and you will see a square cutout on the back and some pins where the jumpers will be inserted.  The pins are labeled JP5, JP6, JP7, JP8 and JP2 on the bottom.  Insert the 2 small jumpers from the high temp kit into pins JP7 & JP8.
4.  Double check connections and then screw the control unit back into place and put the front cover on.
5.  Turn the power back on and the heater should default to 120 degrees F.  You will now be able to raise and lower the temperature on the unit from 100 - 184 degrees F.  Please take into consideration that when the heater is set at say, 180 degrees that the unit will only be able to flow about 1.5 - 3 GPM depending on the heater you have.  The higher the temperature the lower flow you will get.

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 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.