Obsolete Bosch 125BO NG (Natural Gas) Outdoor Tankless Water Heater

Global Protankless Supply currently has 1 of the Bosch Aquastar 125BO NG outdoor tankless water heaters left in stock. The Bosch AquaStar 125 BO model has a pilot light and offers a Piezo push-button ignition and utilizes a modulating gas valve to ensure a constant temperature at varying flow rates. The 125BO is designed to be installed outdoors and has a 120V plug that is only used for freeze protection. The 125 BO is the perfect tankless solution for smaller families and households that only use no more than two hot water applications at a time.

The Bosch 125BO NG is a good replacement for the older GWH 425HNO NG also.  The 425HNO NG was basically the same unit but the 125BO has the standing pilot light and the 425HNO NG used the hydro ignition system.

Bosch has approved these four outdoor heaters for the following areas of the United States:

Florida, Georgia, North Carolina, South Carolina, Alabama, Mississippi, Arkansas, Texas, Virginia (only in zip codes beginning with the first three digits 233-237), Arizona (in zip codes beginning with the first three digits 850-857 and 864), Oregon (in zip codes beginning with the first three digits 970-975), Washington (in zip codes beginning with the first three digits 980-986), California (except in zip codes beginning with the first three digits 935 or 961).

Some people install these outdoor tankless water heaters for their summer homes or cabins in areas of the US and Canada that do freeze. When these heaters are installed in freezing locations the water heaters must be completely drained so that the heat exchanger and pipes do not burst. The Bosch warranty does not cover damage due to freezing.

The WebStone Isolation Valve Kits really make the task of draining these outdoor tankless water heaters easy, so they are especially recommended for this application.

Please call Global Protankless Supply at 866-289-4652 for further questions or to order.

Bosch Therm 660EF/660EFO Tankless Water Heaters

The new Bosch Therm 660 EF and Bosch 660 EFO are direct vent units.  These units take thier combustion air from the area they are installed in.  The 660EF/EFO are compact in design for space saving installations and are only 14" x 20 1/2" x 7".  The 660EF/EFO are designed and approved for reciculation and space heating applications.  The units have electronic ignition and come equipped with built in freeze protection.  The Bosch Therm 660EF vents either vertically or horizontally using 3" or 4" stainless steel venting #AL29-4C. 

The 660EF is manufactured in Japan and comes with a different vent connection than the 830ES, 940ES, etc.  The 660EF needs to be vented with single wall stainless steel venting and is designed to connect directly to "Bosch Vent".  However, a Z-Vent adapter (Part # 2SVSWB03) allows for the use of 3" Z-vent stainless venting to be used.  Global Pro Tankless Supply carries the adapter and all the Z-Vent stainless steel venting to install the Bosch Therm 660EF.  We are the exclusive distributor for the AQ5EF Side-wall Vent Kit for the Bosch 660EF tankless water heater.

The Bosch Therm 660EFO outdoor unit comes ready for installation and does not require any additional cap or venting.

Without the Z-Vent adapter (Part # 2SVSWB03), the customer would have to purchase different venting ("Bosch Vent") to use for the 660EF.

The Bosch Therm 660 EFO is our most compact outdoor model and is loaded with features you’d expect from Bosch, including freeze protection and built-in high temperature capability (160°F).

The Bosch Therm 660 EFO is a good replacement for the GWH425HNO and the 125BO as these units have been discontinued. 

The Bosch Therm 660EF and Bosch Therm 660EFO have an excellent warranty:

• 15 year limited warranty on heat exchanger; 3 year warranty if used in direct recirculating applications

• 15 year warranty on heat exchanger if used if recirculated through a storage tank such as the Ariston mini-tank

• 5 year warranty on all other parts