HVAC question

[projectPONY]

I mostly just check threads for new ones. You still have both of your stangs? I sold the yellow one about 6 years ago and it found it's way back here again.

The coupe and the '66 and this...

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[johnboy]

Yeah, I remember when you posted the truck. Aren't you putting a new motor in it?

[projectPONY]

Yeah, I remember when you posted the truck. Aren't you putting a new motor in it?

Sending PM

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[svauto-erotic855]

I know how it works. It triggers the igniter so the burners will lite and run the heater.

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That is not how it works at all. There is a separate ignition box that looks like a small grey rectangle that does that. The part in the pic is a gas valve and they hardly ever fail. Most of the time the ignitor has failed. Check it for continuity with an ohm meter. If it is good check to see if you get 110volts to it when you try to fire the heater.

[projectPONY]

That is not how it works at all. There is a separate ignition box that looks like a small grey rectangle that does that. The part in the pic is a gas valve and they hardly ever fail. Most of the time the ignitor has failed. Check it for continuity with an ohm meter. If it is good check to see if you get 110volts to it when you try to fire the heater.

I was under the impression that the igniter was ALSO inside the "gas valve." The reason I thought that is because one day the heater wouldn't come on, I looked into it, and I noticed that the burners were not lit. Without thinking about it I tapped on that little box with the handle of a screwdriver a few times and the igniter came on and burners fired. Since then I've had to do this several times to get the burners to fire.

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[kingjason]

That is not how it works at all. There is a separate ignition box that looks like a small grey rectangle that does that. The part in the pic is a gas valve and they hardly ever fail. Most of the time the ignitor has failed. Check it for continuity with an ohm meter. If it is good check to see if you get 110volts to it when you try to fire the heater.

Beat me too it. I have to clean mine every year. Just reach up there with scotchbrite and scrub it a little.

[projectPONY]

Beat me too it. I have to clean mine every year. Just reach up there with scotchbrite and scrub it a little.

What exactly is it that needs to be scrubbed?

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[kingjason]

What exactly is it that needs to be scrubbed?

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That rod. I hit it with steel wool or sand paper or whatever I have handy.

[kingjason]

I can reach mine without pulling it loose. Just reach up below the lines. It will fire and fire but not kick on the fans or get things rolling with this thing is dirty. It has never actually went out. It gets carbon build up on it.

[projectPONY]

I don't see that rod anywhere in mine. I've looked for it several times.

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[projectPONY]

When I get home I'll take a pic of what I see when I look in there.

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[svauto-erotic855]

I should have gone into more detail. There are two types of ignitors. One is called a hot surface ignitor and the other one is a spark ignitor. The hot surface one gets red hot when power is applied to it and that element will fracture and no longer heat up. The spark ignitors sometimes need to be cleaned off but do not fail quite as often as the hot surface type.

The heater fires up like this. The thermostat tells the grey box to fire the heater. The grey box turns on the fan, sends power to the ignitor , and after a preset amount of time it sends voltage to the gas valve to open up the 1st stage that send a little bit of gas down the aluminum tube that ends right by the ignitor. Once the box sees that the pilot is lit it will open up the 2nd stage of the gas valve that sends a gas down the large pipe on the right side of the gas valve that leads to the manifold that feeds gas to the burner tray. There are various safety's in the system depending on the system you have. If you have to wack your gas valve to get things lit you have a sticky gas valve. There is supposed to be a sediment trap plumbed in on the inlet of every gas valve but HVAC guys are lazy and never do it which causes a gas valve to get sticky over time.