Anyone know anything about gas central heating units? (1 Viewer)

[Wayne A. Pflughaupt]

Well, I’m not a happy camper. Our furnace is out. Perfect timing, of course. It’s a late model central A/C – heating unit, a Payne (made by Carrier, I’m told) installed in 2001. I went up to the attic to check it out, thinking the pilot was probably out, or perhaps the thermocouple, and found out that it doesn’t have a pilot. It has an electric igniter of some kind.

Anyone know what this thing might need? A new igniter perhaps? I’m pretty pissed that we paid $4000 for this piece of junk and it survived only few of our exceedingly mild South Texas winters. The old pilot lit unit gave me trouble maybe once in the 16 years we’ve lived here. What, didn’t I pay enough? So much for “better” technology.

Regards,
Wayne A. Pflughaupt

 

[Philip_G]

I'm sure you'll have to rip it out and replace the whole thing... :rolleyes

Relax. Yes, payne is sort of a budget line of carrier. No, it does not have a pilot, likely a hot surface ignitor. Likely this is bad, likely it'll cost you something like $50 and an hour of labor.
Unless it's something else, which is possible but not all that likely.

 

[Bryan X]

At my old house we had a carrier gas furnase without a pilot light and it had a blinking light behind a small round plastic window in the furnace. The number of blinks would tell you what was wrong if it encountered a problem.

If yours has this, it could point you in the right direction. There was one problem mine developed after a couple years that prevented it from working. Fortunately it was an easy fix on my part with no tools or parts. I can't remember the exact terms so bear with me.

If you open the furnace, near the burner you'll see a small cylinder with an 'L' shaped piece of round metal sticking out of it. It is likely screwed into place and has a small wire running back to the igniter. This is the 'Flame Sensor'. Mine would always get 'buildup' on it (not visible to the eye). But it would prevent the sensor from detecting the flame therefore the furnace wouldn't run. Just remove the sensor, rub the metal "L" off with a T-Shirt or something and replace. You'll havet to then reset the furnace to clear out the error and then it should work fine until it needs cleaned again.

Proceed with caution as always though. I'm not a professional Do a search on Gas Furnace Flame Sensor to find out more than I can tell you.

 

[DonnyD]

Some "ignitor" type of furnaces have a problem with the first light up of a season which will cause it to turn off the auto-ignite function if it fails to light after a few tries. Usually they can be reset from the thermostat by turning the system off for a few minutes and then turning it back on therby resetting the ignitor function.....Good luck!

 

[Philip_G]

I don't think the payne has the self diagnostics that the carrier does.

If it's the flame sensor he should be able to pull the top panel off, have someone call for heat and watch, when the ignitor kicks on they glow pretty bright, no ignitor it's something else, ignitor and no flame or flame then shutdown and it's the flame sensor.

It could also be a draft inducer, a bird's nest int he flu, a shot pressure switch...

there's also the obvious, did someone service the AC last spring and turn the gas valve off for some reason? either inside the furnace or the petcock in the gas line to the furnace. Inline with the pipe is open, across the pipe is closed.

 

[DougR]

Is it Completly Dead ?? Does anything at all switch "On" when the Thermostat is set for it to deliver Heat?

 

[Eric Kahn]

first thing to check on any newer gas furnace is the hot surface igniter
turn the unit off, there should be a switch on the unit itself to do this, then turn it back on, it should go through its start up cycle, you should be able to see the igniter lite up, it gets near white hot and gets pretty bright, if you do not see this and hear the gas valve open, you need a new igniter, it is usually held in with one or 2 screws and has a plug on it to disconnect it
they will fail after having a piece of dust or dirt on them, causes them to crack and fail, I just had one fail on me

Call up the people who installed it, mine was covered under the 5 year warrantee I had, yours might be covered

 

[Wayne A. Pflughaupt]

Thanks for the responses, folks.

Philip is right, I don’t think there are any diagnostics – at least not readily apparent.

Doug,
Strangely, it “acts” like it’s working fine. The thermostat kicks it on, and after a minute or two the blower comes on, like it normally would if it was waiting for the burner to heat things up. Only it blows cold air.

Thanks for the tips for the hot surface igniter. I’ll check it out.

Regards,
Wayne A. Pflughaupt

 

[Philip_G]

they fail a lot. Don't think I've replaced a carrier, but the rheem/ruud ignitors they carry about 5 on each truck for after hours emergency calls.

 

[Steve Berger]

Many newer furnaces have a second precharge blower that has to buid up air pressure before the igniter will come on. I get moisture drip into mine and it won't spin because of scale buildup , usually the first demand of the season. If I give it a turn or two manually (small wooden stick) it runs just fine for the rest of the season.

 

[DougR]

I had the same problem that Steve Berger has discribed ! I had Scale building up in the Rubber Hose that goes to the Vent Blower Switch. It wouldn't let the furnace stay running. It would kick in briefly ( Ignitor), then just shut down. Cleaned out the rubber hose of the build up scale and it worked fine.

 

[Philip_G]

you can always jumper the pressure switch closed in a pinch...

 

[aaron campbell]

Could be the flame sensor. Take some fine grit sand paper and shine it up a bit.

 

[Wayne A. Pflughaupt]

Well, I’m confused. I finally got a chance to go up to the attic to check it today, and it’s working fine. Fired right up. I located the hot surface igniter, and it glows nice and bright and fires the gas jets when the valves open. After a minute or two the blower kicks in and it’s blowing hot air inside.

I don’t get it. When I tried it at the first cold snap a few weeks ago, it was only blowing cold air. Same thing again just a week or so ago. When it did that I simply figured it wasn’t working and turned it off, ‘cause that seemed like the smart thing to do. Am I missing something? Should I have let it cycle a few times?

I did find that it has an LED diagnostics set-up – nice to know for future reference. Thanks for the heads up on that, Bryan.

Regards,
Wayne A. Pflughaupt

 

[Bryan X]

Glad to hear it's working now. If you shut the power off to it, that probably 're-booted' it and whatever the error was it was reset (until it happens again). Hopefully it will keep working for a long time.

 

[Wayne A. Pflughaupt]

Or at least next time I won’t be so quick to let it sucker me into thinking it’s broken!

Thanks again to everyone who responsed in my hour of need.

Regards,
Wayne A. Pflughaupt

 

[DougR]

Good to hear you got it up and running !!

Now if you don't mind ?
I'll send you some of this 10 degree weather your way to Test out your Furnace !!