Need some help with heater.

[Punisher]

So...my gas heater stopped working.
It seems like something is not telling it to kick on.
Pilot light is lit but I reset it anyway.
Thermostat is OLD. At least 30 years old minimum. It's an old mercury type. I thought it might be dead so I popped it off and touched the 2 wires together to test. It is basically an on off switch right? I could theoretically swap it with a toggle switch and turn ot on and off manually right?
Either way it didn't help.
It's the weekend so no plumber until week at the earliest.
It does seem to have power because when I turn off the emergency switch the water light goes on and off. It's green if it matters.
1. Is there a troubleshooting or repair step I missed?

2. Even if I need a plumver anyone ever have this? If so, what was the issue and a ballpark repair cost?

Thankfully winter is on the way out and we are gonna pick up a heater at Walmart tomorrow to be safe.

[Alefroth]

If it has a flame sensor, it could be bad.

[em2nought]

Not much up on anything "gas". I do know that when I move my thermostat for my electric heat and air conditioning that it doesn't immediately start up, there's some sort of a delay built in.

[Daehawk]

No idea with gas.

[stessier]

If it has a flame sensor, it could be bad.

When we had trouble, that was our cause.

[Unagi]

If it has a flame sensor, it could be bad.

When we had trouble, that was our cause.

@Punisher
Does the heater try and start at all - and then just stop? Generally, if the problem is with a safety sensor, you will still hear the heater being told to start - and it will fail in some way - but if there is just never any sound/click at the heater, I would almost think it's more likely a thermostat problem (not sure if You ruled that out or not). Could also be the circuit board on the heater that is told to start and does nothing with that signal (which would be silent).

The flame sensor in one of my (previous property) heaters was a 'glow plug' of sorts that was heated by the lit burner (not the pilot), and if that ceramic loop didn't get heated up, it wouldn't send its signal that the flame was heating it - and the gas would shut off. The broken flame sensor that we had was a crack in that ceramic sensor which didn't allow the current to run through it, and so even though it was being heated by the burner flame it would think it wasn't and the gas would shut off and it wouldn't heat. But you would hear it try.

[LawBeefaroni]

Is a plumber really the best person to deal with a failing gas heater? We always call heating & cooling specialists.

[Punisher]

Re thermostat.
I took it off the wall and just twisted the 2 wires together to bypass it. I'm assuming this would work if its just the thermostat.

Re. Starting. No noise at all.

Re. Plumber. I don't know. Weve just always called them? I'm assuming a specialist would be more expensive?

[Alefroth]

A plumber is a specialist, just not with furnaces.

If it's not trying to come on at all, it probably isn't the flame sensor.

[Unagi]

Re thermostat.
I took it off the wall and just twisted the 2 wires together to bypass it. I'm assuming this would work if its just the thermostat.

Re. Starting. No noise at all.

Re. Plumber. I don't know. Weve just always called them? I'm assuming a specialist would be more expensive?

Okay the plumber thing makes no sense.
Perhaps if it was a gas line thing, but even then - plumbers handle water.
As said - you’re paying for the wrong specialist if you call a plumber.

My guess is that an electrical component in your heater is broken.

[Daehawk]

I remember a guy I knew had a trailer he just got with gas heat. it was damn cold up there in the mountains and we decided to stay the night instead of trying to drive back. Bout froze even with the stove eyes on and the oven. The next morning I looked at the heater and the damn pilot was out lol. I reached in and relit it and turned it on and it was working fine. Sigh.

[Punisher]

So...i found out that my plumber is a plumbing and heating specialist so that might be why weve always used them.

It was a panel on the heater. It was the aquastat. The part alone was $400.
In the before times I might have looked into the part and install myself since it looks purely electrical but I don't trust myself as much anymore.
Total was $600. Hopefully they can either split it in 2 or at least wait until next Wednesday when I get my ssdi check.
Might be time to ask for a raise. I've been working hard at being disabled for over 2 years now.

[Unagi]

My guess is that an electrical component in your heater is broken.

[Montag]

So another thing from personal experience. There is a pressure sensor that verifies the forced air draft is working. It will have a rubber hose going to the exhaust. The port the hose connected to can get clogged. This can be cleared with buss wire or a wire hanger. The pressure sensor can also fail.