I am in great need of some help. Got back from vacation and my heater stopped working.
What I noticed: can not change mode anymore (it is stuck on "STANDBY"). The display
shows b0, which is fine since it is in bypass - driven by my ProLogic panel.
What I tried is to disconnect from panel and work as stand-alone. This did not work, since
I can not change modes...
Measured the input voltage at the power supply pins and it is 24VAC.
Next I tried to exchange the Integrated Control Board and there was no change except
the fact that now I get code "73" when heater is activated from the panel and I do not
see b0 code anymore.
I am at a loss on where to find error codes, specifically code 73.
Could anybody on this forum enlighten me as to where to look for code descriptions,
or any other advice that would direct me on the right path?
Failing this, a quick (and expensive) call to a Hayward technician is needed... or maybe not?