Rheem RTG2-42 Troubleshooting Manual page 44

Did the
unit go to
main
burner?
Yes
Unit appears to be OK.
Did the
unit go to
main
burner?
The problem is with the
remote control or the wiring
to the remote control.
Disconnect all additional
wiring to the remote control
and connect it directly to the
Remote Terminal of the
PCB.
Yes
Attempt to restart the unit.
Did the
unit go to
main
burner?
Yes
No
Disconnect all remote
controls from the PCB
and attempt to restart the
unit.
No
OK - If you gone this far, there is one more thing to check. The pick-up
sensor in the water flow control may be bad; or the board may be bad.
Try this test:
Check connector S between the Red and Black. With the unit ON and
no water flow, you should be 11-15 DC volts. If not, replace the PCB.
IF you have voltage, then.......
With the water flowing, measure 2-5 DC volts between the Brown and
Black wire. (This is measuring water flow thru the control). IF you have
a reading and no main burner, replace the PCB. If you do not have a
reading, replace the water flow sensor.
Cold water inlet temperature may be to warm to restart the unit. While in
maintenance mode, go to 3y and determine the cold water inlet
temperature. If the inlet cold water exceeds approximately 75 degrees,
you may have a problem with the cold water being too warm for the
machine to operate. Run the cold water for at least 3 minutes and recheck
temperature.
Call technical service at 1-800-432-8373.
No
Replace Remote Control
Replace Remote Control wiring
43
SVC 810 Tankless Troubleshooting Manual