Mmm… Heat…
This morning when I woke up, my house felt a little cool. I wasn’t sure why, so I took a bit of a look into it while brushing my teeth. It turns out that I believe my furnace is having its same old problem that it’s had for the last few years. This, combined with my failing air conditioner, makes me think that it’s about time to replace the heating / cooling stuff in the house.
See, here’s the furnace problem: For some reason when I have the grated cover installed on my furnace (as seen here), the furnace will occasionally fail to work. As in, it’ll light the pilot, light the burner, then shut the burner off after ~2 minutes. Then the cycle will start over again, and the furnace will short-cycle like that until the house is up to temperature. I’ve found info online saying that the flame sensor could be dirty, but the problem doesn’t happen when the door is removed, so I’m quite confused… The blower also runs and never cuts out, even when the flame is cut off.
So really, I’m just confused.
Coupled with the slow leak in my AC, I think it may just be time to replace things… That’s $2500 I don’t want to be spending, though. :\
UPDATE: Maybe some of the folks around here will be able to help.
have you tried calling a furnace guy
Nope, because that automatically entails >$100 charge. I know it needs to be replaced, I just don’t want to do it yet… The problem is also so damn sporadic that I think it *may* be a bad PCB which goes south when flexed.
There’s also no reason I can’t troubleshoot such things myself, and I’d rather spend a few hours trying to solve the problem before I just outright pay someone for it. Especially when that someone may not be able to fix the problem.
it just seems cheaper/less hassle to replace the part than the entire system, but thats just me im like that.
Yeah, but the question is what part? It may be the PCB, or it may be a sensor, or I guess it could be something esoteric… I’m trying to work through the troubleshooting myself first.
my furnace was doing something weird like that a few winters ago. i called a repairman, and it turned out to be a quirky wiring issue, and it was very easily fixed and only cost me the service call. i wouldn’t rush out to buy a new system until you’ve had someone out. sure, you can trouble shoot stuff, but at some point you should have a trained HVAC person look at it, too.
good luck (:
Oh yeah, I know… I’m just trying to get it sorted out myself first. If you don’t mind, could you tell me what the symptoms you had were?
it would click on and the fan would run, and then it’d click right off. it wasn’t igniting or something – i remember coming home and it being verrah cold in the house.
Ahh, okay. Probably a problem with the flame sensor… Makes sense. :)
if your system is less than 20 years old you might be better off putting a few hundred dollars into it and keep it going for a while. If it’s older than that, it’s probably time to start thinking more about replacement.
If it isn’t working with the cover on, couldn’t you just leave it off? Are there any wires near the cover that the cover could be bumping when it’s on?
You might consider having someone come out and do an annual inspection/cleaning. If that doesn’t fix the problem, usually they won’t charge you for the second house call if it is within a few weeks of the first. The cleaning should be under $100.
We had the ignition replaced on our furnace last year for about $300 and it’s been working well since then. Before that it would just quit working at random. I completely understand wanting to investigate yourself before you call someone in and get charged for something you could have done. Also consider checking the wiring to your thermostat. Something might be loose and throwing things off. Good luck!
I too, had such a bit of furnace weirdness
The problem was (recalling from memory here) the thermal coupling. Start stop start stop blow out pilot light… all that jazz. Furnace was in the laundry room so opening the door somehow lowered the # of incidences. It got bad enough eventually that when the heat kicked on the pilot would die, first cycle.