Thermostat or furnace?

[ProudToBeBlueInRhody]

Lately I've been having an intermittent issue with my oil burning furnace and heating system. I'll turn up the thermostat, and hear a clicking sound from the furnace, but the heat won't come on. I also hear this occasionally as clearly the furnace is trying to come on in response to the thermostat automatically, but nothing happens. It will hum for awhile, then click off.

The furnace does still run by itself now and again, especially after I take a shower or do the dishes I'm assuming in response to using the hot water. It has turned on a couple times today by itself, maybe because it senses the basement getting colder as opposed to the bulk of the house?

As I said, it's intermittent. I had this issue a couple of weeks ago, then it went away.....it was happening on Monday before the storm knocked out power and then was fine Tuesday after the power came on and back to not really working tonight.

Any ideas?

[jeff47]

1. If the furnace responds somehow, then it's the furnace. If it doesn't, it could still be.

If the only demand is coming from the thermostat, then any activity on the part of the furnace means it got the signal from the thermostat. If you have a combined system where you get heat and hot water from the same unit, then the hot water demand could cause it to turn on.

Easiest test is to make sure the furnace isn't doing anything, and then crank the thermostat all the way up.

If the furnace keeps doing nothing, it is either the thermostat or the furnace. If the furnace does something, it's the furnace that has the problem.

[Warpy]

2. Hard to say, but the clicking at the furnace suggests

there is a faulty connection from the thermostat to the burner switch or something wrong within the stack control.

I'd call a professional for this one.

While you can clean the soot out of a stack control yourself, it's a nasty job and there is no guarantee that's the problem.

[MADem]

3. +1...I had a similar issue once and that was the very problem. A pro fixed it in no time. nt

[ProudToBeBlueInRhody]

4. Thanks, 'm pretty sure that's part of it

My burner definitely needs a cleaning, I let it lapse because the guy I usually have do it yearly retired last year.

[Thor_MN]

5. Been a long time since I've had an oil burner, but

my guess would be air in the fuel line. I used to have to bleed the fuel line after the furnace had not been run for awhile. There was a bleeder valve on the oil filter housing and until clear oil was coming out (it was milky if air or water was mixed in) the burner wouldn't start running. Then again, that was 35 years ago...

[Kaleva]

6. Do you have a boiler and not a furnace?

Is the system maintaining the temp you set at the thermostat? You didn't mention if it's cold in your house.

If you have a boiler, it may already be up to high limit when you turn up the thermostat and the clicking you hear is the relay in the aquastat closing which powers the circulating pump but not the burner assembly as the temp is already at high limit.

If the temp in the house is what you have the thermostat set at (within a degree or two), there may be nothing at all wrong with your heating system.

[sinkingfeeling]

7. Sounds like the igniter is going bad.