Determining the Correct Size Bosch Whole House Electric Tankless Water Heater

For determining the correct size Bosch electric tankless water heater for your home there are a lot of variables that need to be taken into consideration.  Bosch offers 3 whole house electric tankless water heaters.  The Bosch Tronic 6000C WH17, the Bosch Tronic 6000C WH27 and the Bosch Tronic 5000 WH36.  The WH17 is a 17 Kilo Watt (KW) unit, the Bosch WH27 is a 27 KW unit and the Bosch WH36 is a 36 KW unit.  Each of the Bosch whole house electric tankless provide a little more gallons per minute (gpm) from one to the other.  When sizing your home for the correct Bosch electric tankless water heater you first want to decide how many gpm at one given time will you use.  The next thing to take into consideration is your incoming water temperature.  All these factors will determine what size electric tankless will be good for your home.

Please see the diagram and chart below to determine which Bosch electric tankless will be good for your application.

Please feel free to call us at 866-289-4652 for further questions or to order a Bosch electric tankless water heater.  Also visit our website at www.prowaterheatersupply.com  

Serial Number Cutoff for Logic PCB for Bosch Tronic 6000C WH17 & WH27

Bosch Thermotechnology is always upgrading the Bosch tankless water heaters and has recently updated the Bosch Tronic WH17 & WH27.  The new model numbers for these heaters are:

Bosch Tronic 6000C WH17 - Model #45-551721

Bosch Tronic 6000C WH27 - Model #45-557721

There have been several upgrades to the units and one of theses changes is to the Logic Printed Circuit Board (PCB).  The new Logic PCB for the Bosch Tronic 6000C WH17 & WH27 has a different part number from the older units.  Below is the new part numbers and also the serial number cutoff for the PCB boards.

Serial Number Cutoff:

WH17
Logic PCB #8-738-710-921, this would be for any new 6000C WH17 with serial number 555 A 800001 or higher

WH27
Logic PCB #8-738-710-922, this would be for any new 6000C WH27 with serial number 555 A 800271 or higher

New Bosch Tronic 6000C WH17 & WH27 Electric Tankless Water Heaters

Global Protankless Supply is now carrying the new Bosch Tronic 6000C series model WH17 & WH27 electric tankless water heaters.  Bosch is always making improvements and upgrades to the tankless water heaters.  The Bosch Tronic 6000C WH17, part number 7736503050 and the Bosch Tronic 6000C WH27, part number 7736503051 now come with a temperature control knob on the front of the unit and also a digital display to show the set temperature. The new Bosch Tronic 6000C WH17, model number 45-551721 begins with serial number 555 A 800001.  The new Bosch 6000C WH27, model number 45-557721 begins with serial number 555 A 800271.

Bosch has made other upgrades to the unit and some of the highlights of the new units are listed below.

• Provides endless hot water for 1-3 major applications at a time*
• 97 % efficiency rating
• Compact & lightweight
• Electronic flow sensor
• Element modulation provides a constant output temperature
• Filter screen on inlet
• Improved temperature stability & control
• Enhanced scale resistance

*Dependent on location and model used.

The Bosch WH17 needs to be wired in using 8 ga wire to 2 - double pole 40 amp breakers and the home should be equipped with at least a 150 amp panel box.

The Bosch WH27 needs to be wired in using 8 ga wire to 3 - double pole 40 amp breakers and the home should be equipped with at least a 200 amp panel box.

There is a 5 year warranty on the heating elements and 2 year warranty on all other parts.

Below is a sizing chart that may help determine which model electric tankless may be best for you in the area where you live.

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.