# Water Heater won't light



## adfuhrer (Dec 10, 2010)

I have a 6 year old AO Smith propane water heater, model #GPSH 50-101. The heater wont light by itself and shows an error code that the system is in lockout.If I unplug the unit from the wall and plug it back in it tries to light 3 times and shuts itself off and shows the same error code.If I unplug the 3 wires that go to hot surface ignitor and sensor and plug them back in,it will light and work great. Do I need to replace these parts or could it be something else?


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## Ron6519 (Mar 28, 2007)

Bad thermocoupler?
Ron


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## Hixheat1 (Dec 6, 2010)

adfuhrer said:


> I have a 6 year old AO Smith propane water heater, model #GPSH 50-101. The heater wont light by itself and shows an error code that the system is in lockout.If I unplug the unit from the wall and plug it back in it tries to light 3 times and shuts itself off and shows the same error code.If I unplug the 3 wires that go to hot surface ignitor and sensor and plug them back in,it will light and work great. Do I need to replace these parts or could it be something else?


Send a pict. Does it have a drain off of the flue. It sounds like a high effi unit. If so probel drain problem


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## the_man (Aug 14, 2010)

what error code? it should have a list of all codes in the manual that came with the tank.


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## adfuhrer (Dec 10, 2010)

error code says system is in lockout


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## Ron6519 (Mar 28, 2007)

Did you ever get this fixed?
Ron


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## gavinol (Dec 18, 2010)

you need to turn the control knob to the pilot light mark so that when it lights it creates enough heat to cause the thermocouple to open ( let gas through) and then turn the knob to the run position...If that does not do it, you need a new thermocouple that usually unscrews from the main control... Be carefull, gas is nothing to fool around with if you are not to familiar with it.... good luck


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