Thursday, May 14, 2015

PCB Control Boards for Powerstream Pro & Bosch Tronic 5000 Electric Tankless


The PCB control board (Printed Circuit Board) is a thermostatically controlled circuit board that allows the whole house electric tankless water heater, models WH17, WH27 & WH36, to be manually controlled by a temperature dial that would range in temperature from 86-131 degrees. The PCB in conjunction with a flow transducer enables the PCB to turn on additional elements in the heater as necessary depending on the amount of gallons per minute (gpm) flowing through the heater.

The PCB would recognize many factors in the function of the heater to maintain a steady temperature and all of this is determined on where the temperature knob is set to, the gpm flowing through the heater, and the temperature of the incoming ground water.

To obtain the maximum heating potential of the Bosch Tronic 5000 electric tankless water heater it must be wired correctly and have the full required voltage to the unit. The Bosch Tronic 5000 WH17 would require 2 independent double pole 40 amp breakers wired with 8 gauge wire and could draw a maximum of 80 amps at full flow through the heater. The WH17 would require the home to be supplied with a minimum of a 150 amp service. The Bosch Tronic 5000 WH27 would require 3 independent double pole 40 amp breakers wired with 8 gauge wire and could draw a maximum of 120 amps at full flow through the heater. The WH27 would require the home to be supplied with a minimum of a 200 amp service.  The Bosch Tronic 5000 WH36 would require 3 independent double pole 60 amp breakers wired with 6 gauge wire and could draw a maximum of 180 amps at full flow through the heater. The WH36 would require the home to be supplied with a minimum of a 300 amp service.

The maximum inlet water temperature allowed into the electric tankless is 86 degrees Fahrenheit.

The Bosch Tronic 5000 WH17, WH27 & WH36 have had many upgrades and engineering improvements over the years. In January 2007 the WH17(RP17PT) & WH27(RP27PT) went from having copper canisters that contain the heating elements to an upgraded Polymer module. The PCB control board was also upgraded to maintain a more steady temperature that works with the heating elements in the polymer modules.

Below are the designated PCB control board part numbers for the units before and after 2007.

Before 2007 with serial #60A 00000 or lower:
Powerstream Pro RP17PT PCB with copper can units, part #93-793777
Powerstream Pro RP27PT PCB with copper can units, part #93-793778

After 2007 with serial number between #60A 80000 - 107:
Powerstream Pro RP17PT PCB with polymer units, part #93-793843
Powerstream Pro RP27PT PCB with polymer units, part #93-793844

Newest Bosch Tronic 5000 units with serial number after 108:
Bosch Tronic 5000 WH17 PCB with polymer units, part #8738701732
Bosch Tronic 5000 WH27 PCB with polymer units, part #8738701738
Bosch Tronic 5000 WH36 PCB with polymer units, part #8738701744