AO Smith GPS 75 200 not working

Old 04-30-13, 07:23 PM
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AO Smith GPS 75 200 not working

I have an AO Smith GPS 75 200. Many times a day I find that I have no hot water. The error code I receive is: fist light on, second off, last four are on. I can't find this code in the documentation. If I turn off the power, then turn it back on, the boiler starts heating up again, and I get hot water. However, at some point, for some unknown reason, it goes off again. Any advice is appreciated.
Old 04-30-13, 07:41 PM
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Here is the service manual.

Check the lights again to be sure. Although When I see codes not in the manual its always the gas valve 98% of the time.

Also with a code like that it may be a slim chance its the wire harness. This travels inside the tank and where they enter gets shorted at times. Wiggle it at all connecter ends and where it enters the heater jacket. Do this while the heater is running and see if you get intermittent failure.

Here is the repair manual. Same one I carry.....

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