Thursday, May 31, 2012

Gas Conversion of Pro Gas Tankless Water Heaters

Some of the Bosch Professional gas tankless water heaters can be converted from one gas type to the next, i.e. from Natural Gas (NG) - Liquid Propane (LPG) and also from LPG - NG.  The Gas Conversion Kit, part #8719002176 includes a jumper for placement on the control board, a set of instructions for calibrating the gas and air mix and also some stickers to be placed on the heater stating it has been converted. 

The tools required for the gas conversion are:
  • Flat and Phillips Screwdrivers
  • #40 torx driver
  • Digital CO2 Gas Combustion Analyzer
  • This procedure must be performed by a licensed gas technician
The Bosch Professional Non-condensing heaters such as the 940ES/940ESO/830ES/715ES/635ES and the Evolution 500 CAN be converted using the gas conversion kit.

All of the Bosch Therm condensing heaters such as the C1210ESC/C1210ES/C1050ES/C950ES/C800ES and Integra 500 CANNOT be converted as the units have a special plate built into the burner tray.  This extra plate in the burner tray was designed and instlled to give the heater the ability to be installed at higher elevations up to 8000'.

Also the Bosch Therm 660EF/660EFO/520PN/520HN/425HN/425EF/330PN CANNOT be converted as they are not designed at all for gas conversion.

Friday, May 25, 2012

Bosch Tronic 5000 WH17 & WH27

Bosch Tronic 5000 WH 17 & WH27 Electric Tankless Water Heaters

Ideal for replacing your electric storage tank water heater. The Bosch Tronic 5000 WH17 & WH27 electric whole house tankless water heaters are compact and powerful and can be installed virtually anywhere inside the home. Advantages include endless hot water, reduced electricity costs and substantial space savings.

Designed to replace a 20 - 40 gallon electric tank. The Bosch Tronic WH17 &  Bosch Tronic WH27 electric tankless water heaters are built to last. They have Plastic Polymer Modules and brass fittings. Each heater module is protected by an electro-mechanical thermal cut-out. If the temperature of any of the heater modules gets too high (over 195 degrees), then the cut-out will trip and cut the power to that heater module. If the cut-out trips, it must be reset while the circuit breakers are off. If you are not comfortable or qualified to perform this task, consult the original installer or a licensed electrician. This cut-out will only trip in exceptional circumstances. These small electric tankless water heaters can be installed virtually anywhere in the home and, of course, produce an endless supply of hot water.

There are many changes in the new Bosch Tronic 5000 WH17 and the WH27 compared to the older models Powerstream Pro RP17PT and RP27PT.

The new improvements for the Bosch Tronic 5000 WH17 and the WH27are:
  • The units overall height is shortened by 4 inches due to reconstruction and placement of the main PCB board in the bottom of the unit.  (WH17 PCB Board #8-738-701-732, WH27 PCB Board #8-738-701-738).
  • The Heating element assembly modules inside the unit have been redesigned to change the flow of the water in the modules to a different angle so as to not allow the mineral deposits to build up on the elements.
  • There has been new single triac and dual triac PCB boards attached to the top of the heating modules as to give the heater more sensibility and maintain a more consistant heat.  (Single Triac PCB #8-738-701-733, Dual Triac PCB #8-738-701-723).
  • The Thermal Cutouts on the top of the heating modules have been redesigned to trip at a little lower temperature of 195 degrees F to keep the elements from being damaged and overheating and hurting the piping and modules.

The minimum activation rate required for the unit to activate. (Activation rates: WH17 = 0.6 GPM, WH27 = 0.8 GPM).

The WH17 & WH27 are designed for cold potable water only. These water heaters are not designed for preheated water or recirculation applications. Increase flow rate where ever possible if water is coming out too hot.

Verify incoming water supply is at least 30psi. For people on well systems, the recommended pressure range is 30-50psi.


Maximum flow rates for each unit are as follows. WH17 = 2.3gpm, WH27 = 3.5gpm.