Have a 2001 Hayward H200 heater that came with the house. It didn't work when we opened the pool, but since we'd lived here less than a year the warranty covered it. Received a new pilot generator assembly and gas valve.
I used the heater twice, the first time to warm the water from 74 to 84 to get the pool open. Then about a month later to bump it up a few degrees, it's been off since then.
I tried to fire it up a few times recently and the pilot light would shut off. My dad has some HVAC experience and mentioned the gas pressure was probably too low. Walked through the troubleshooting chart and slightly increased pressure and pilot stays lit.
Problem is the burner won't fire up.
I have a multimeter and started to mess with this thing. It's a millivolt system. I can fire up the pilot light and when I measure I can get 522 mV from the pilot generator. This is with the gas button pressed down. The second I let go and the button pops up mV drops down to the 200 range. I believe this is my issue because 200 mV isn't enough to open the gas valve to fire up the burner.
Any idea what's going on?
1) Should voltage drop once I stop pressing the pilot light button?
2) Even though voltage drops it's steady across the TH connections, meaning I think my wiring is good.
3) What voltage should this thing be at to get the gas valve open? Does it only need to be 500 mV initially?
4) Why would this have worked recently then stopped? Nothing changed except the pilot would shut itself off. Could that have caused damage somehow?
The company that "fixed" it by replacing the parts makes the term incompetent seem like a compliment. If I called them they'd charge me a usurious rate to look at their broken work.
The techs told me this thing was old, but the burners are good and the heat exchanger is good. So with a new pilot assembly and gas valve I should have a working heater in an old enclosure.