Water Heating Systems

Seisco Tankless Heaters

Electric Water Heaters

Matching Procedure

Warning

This guide was prepared for use by a qualified technician. no one should attempt service on Seisco units unless they have the experience and skills to work on electrical equipment

For Microprocessor Control Panel Boards

This procedure enables the temperature sensors to be properly matched to the control’s microprocessor and is required after replacing a control panel board. Also, it may be necessary to perform the matching procedure to an existing control board after adjusting or replacing Temperature sensors, Temperature sensor Wires or resetting a High Limit Switch.

1. Turn off all power to the heater. Note: many models have multiple power circuits and breakers.
2. Run cold water through the heater for approximately 5 minutes to allow the heater to cool down and to allow the chamber temperature to become uniform.
3. With the power off and water running, disconnect one of the high limit wires (brown wire) from near the top of the control board.
4. Turn the power on to the heater. The control board will beep and the LED will flash red and green. This is normal.
5. Locate the blue button on the control board, located left side of the board below the thermostat knob.
6. Push & hold blue button in continuously for about 10 seconds, then release.
7. After releasing the blue button, there should be a distinct low tone beep. This is the confirmation tone that the match was successful. If no low tone beep is heard, go to the previous step #6 and try again*.
8. After confirmation tone is heard, turn off all power to the heater.
9. Reconnect the brown wire to the control board.
10. Turn on all power to the heater, make sure all the breakers are on.

* If the no confirmation tone is received after 3 or 4 attempts, then check the temperature sensors and temperature sensor wires with the ohm meter. Go to the Component Testing Table for expected ohm readings.