Puzzling Hayward heater troubleshooting

[Ed.]

Hello, I'm new to this forum and forgive any silly questions. I have a Hayward H250 gas heater that will not fire up. I read several posts about diagnosing and followed every step and still no luck. All switches measure continuity with a meter including the thermostat. The pilot light is ON. I jumped the gas valve and it lit up until I removed the jumper.

I have a gathering this week and wondering if it would be safe to place the jumper on the gas valve (TH-TH connection) and light up the heater. If I leave the jumper on all the time during the day of the gathering, would this be ok? Also, will my thermostat still control the pool temperature?

 

[cowboycasey]

Welcome to TFP

Safety, safety, safety... there is something wrong with your heater and the last thing you want is to jump something and have a heater blow up while you friends or anyone is there.. not something I would recommend even if it was safe..

Sorry, some may look at this different....

 

[ps0303]

DO NOT do that. You need to step thru all of the safeties and see what is affecting the unit. You also need to check out the pilot assembly and see if it is generating enough millivolts to get the system to run.

 

[Ed.]

Got it! I'll repeat troubleshooting testing again thoroughly and consult technician unless others have any further thoughts. Thanks

 

[Discobrian24]

With a milivolt system it is important to keep all wire connectors clean and free of corrosion. I usually replace corroded connections each time I open the pool for the year. My heater is a 1994 and still works great. Never bypass safeties...

 

[danpik]

If it lites with a jumper then the thermopyle should be good. This is what supplies the power to the gas valve. Go back thru the safeties with your meter and check voltages to ground. One of them is not playing well with the others. Also, unplug and reconnect all of them. Any minor corrosion can weaken the voltage signal enough to prevent the heater to fire.