HELP with furnace in Wheatridge!!!

[bellavite1]

Stupid furnace is driving me crazy.

Changed igniter, pressure switch, tried different thermostat, changed board (not positive that it is a good one, though).

Completely random issue: will run great for a few days and then will start acting up for no discernible reason.

Ignites, runs for a few secs and then turns itself off.
The board gives 8 blinks, no idea what that means, the manual troubleshooting guide only goes up to 7 blinks...

Reboot it enough times it eventually restarts, but not this time.

Currently with no heat.

Who is the forum go-to-guy?

I NEED HELP!!!

[Erni]

See if you have a temp sensor in the path of the gas flames. Not sure of the name. Single wire attached to it. It?s L shaped and one tip is blasted by furnace flame.
When mine get dirty I get an on off cycle that turns burner on and then off in 30 seconds. Repeats constantly


To fix this. Remove sensor. Using steel wool clean off the contamination. Reinstall. Spend money you saved on guns.

[Erni]

It?s called a furnace flame sensor.

[Joe_K]

Stupid furnace is driving me crazy.

Changed igniter, pressure switch, tried different thermostat, changed board (not positive that it is a good one, though).

Completely random issue: will run great for a few days and then will start acting up for no discernible reason.

Ignites, runs for a few secs and then turns itself off.
The board gives 8 blinks, no idea what that means, the manual troubleshooting guide only goes up to 7 blinks...

Reboot it enough times it eventually restarts, but not this time.

Currently with no heat.

Who is the forum go-to-guy?

I NEED HELP!!!

[Wulf202]

It?s called a furnace flame sensor.

This. They cost about $8.
Last time I had a service call it cost $330 to have it put in while I was put of town

[bellavite1]

I have already cleaned it
I went to a place to get my pressure switch today and they wanted $60 for a flame sensor.
That's because most places don't sell retail, only wholesale to HVAC companies.
Regardless, once it's cleaned, it is just a piece of metal, not much can go wrong there.
Any of our members in the trade at all?

[electronman1729]

Not a forum guy, but Tobin Heating is the guy.

[dbgunner]

I have been having the same issue with my furnace. It will turn on for 10-15 seconds and then turns off.
I would be sitting at home and then thinking to myself "Dang it is getting cold in here". Would have to turn power of/on several times then the furnace would stay on.
Going to look at the flame sensor and clean if needed. Thanks for this thread. Hopefully I will save myself a $330 service call for an $8 part.

[Erni]

I have already cleaned it
I went to a place to get my pressure switch today and they wanted $60 for a flame sensor.
That's because most places don't sell retail, only wholesale to HVAC companies.
Regardless, once it's cleaned, it is just a piece of metal, not much can go wrong there.
Any of our members in the trade at all?

Hmmm. It could have gone bad too. Did u look up the board and see what the blinking light code means?


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[bellavite1]

I just put back the old pressure switch and it fired up.
Will probably work for a few days and then we'll have issues again...
I guess the board is the next thing?
Hopefully I can return the switch and put it toward a control board.

[Wulf202]

I just put back the old pressure switch and it fired up.
Will probably work for a few days and then we'll have issues again...
I guess the board is the next thing?
Hopefully I can return the switch and put it toward a control board.

You're just throwing parts at it. Trouble shoot it by looking up the code first off.

[Wulf202]

Audible click followed by the fan
It then will check the pressure switch.

Audible click. Flame igniter will heat up or spark igniter. Either orange glow or a bug zapper sound

Audible click. Gas valve turns on.

Hear the ignition of the gas. See a blue glow

It then checks with the flame sensor to make sure it's not dumping pure gas into the house.

Which step do you get to?

Ace in Aurora off iliff usually sells hvac parts.

[Wulf202]

I have already cleaned it .....
Regardless, once it's cleaned, it is just a piece of metal, not much can go wrong there.

That wire goes to important bits inside the metal. That can go bad.

[Wulf202]

I just put back the old pressure switch and it fired up.
Will probably work for a few days and then we'll have issues again...
I guess the board is the next thing?
Hopefully I can return the switch and put it toward a control board.

The line to the pressure switch goes to the fan. Inside that little barbed fitting can gather debris. Clean it with a paper clip. Then blast it with canned air if you have it.

Check the hose for pin holes plug one end and blow on it. You can also cycle the pressure switch and check its continuity.

[bellavite1]

Did the continuity test on the pressure switch, all good.
Cleaned the hole in the fan already as well.
Managed to find the error code, pointing to the thermostat.
I already replaced the old thermostat with one i had laying around (never used), and did not make a difference, would work for a few days and then crap out.
I assume i could have ywo bad thermostats, I guess.
Ill go buy a third one tomorrow and if nothing else I should be able to return it if it doesn't fix things ...

[Wulf202]

Managed to find the error code, pointing to the thermostat.

That's.... unusual. Like I've rarely seen a board in a home furnace that can diagnose a tstat issue. And the ones I've seen than can, the HVAC system is worth more than many vehicles are.

What brand of furnace? If it's a Coleman 8 flashes does not mean a thermostat issue. It just means its cycles too many times and locked out

Goodman 8 flashes means no ignition detected. Could be ignitor or flame sensor


After re reading a couple of times. Your description of the symptoms seems to be the flame sensor.

[fitterjohn]

I have already cleaned it
I went to a place to get my pressure switch today and they wanted $60 for a flame sensor.
That's because most places don't sell retail, only wholesale to HVAC companies.
Regardless, once it's cleaned, it is just a piece of metal, not much can go wrong there.
Any of our members in the trade at all?

Even if you cleaned it you need to make sure it?s positioned correctly and that it does not have a crack in the porcelain. I have diagnosed that before when they have a hairline crack in them.

[eddiememphis]

What brand furnace? Make model and serial number.

A flame sensor is not just a piece of metal. Some of them have a bi-metal switch in it that allows the furnace to run. Cleaning it does nothing.

[Jamnanc]

Had the same issue. Burned for three seconds, flared out. Flame sensor needed scrubbing.

[ray1970]

Likely the flame sensor. I have to clean mine a couple of times every season. I clean mine with some 320 grit emery paper.

Also, depending on your thermostat, if it has a battery or batteries inside and you can?t remember the last time you replaced them it might be worth putting new batteries in. I was having weird issues once and although everything looked okay on the display apparently the batteries were weak enough that the thermostat just couldn?t perform properly.

[bryjcom]

Call a company and have them professionally diagnose it?

Or maybe keep throwing parts at it…. I dunno ��‍♂️

[bellavite1]

Well, calling a company was the whole point of this thread...as in "is there somebody that you guys recommend, ideally a Forum member".

The furnace is a Goodman (model GDS80453ANA, s/n 0406202120) , but the board is a ICM replacement control unit
The manual that came with the ICM board shows 8 flashes as indicating a faulty thermostat.
I will try to find a flame sensor as well, JIC (I mean, $8, might as well).
Hopefully ace hardware carries them, because the other place tried charging $60 for it.
Where else could I buy one?

[Erni]

NcGukin hardware in Boulder might have em

[fitterjohn]

Can you post a picture of the part of the manual that showed what the 8 flashes says, (not that I doubt you, just incase it’s being interpreted wrong). Post a picture of the icm also. I would offer to come look, but won’t be off oncall for a while and won’t be able to make it south for a few weeks at least

[bellavite1]

Here's the manual page92579

[bellavite1]

Cannot upload a picture of the board (don't know why...sometimes I can, sometimes I can't, from the same phone and computer), but it's a ICM286 Furnace Control Board Replaces:Goodman B18099-26S 0130F00005S.

[bryjcom]

Sounds like you maybe lost a ground to the common side of the transformer. The behavior you describe sounds like a dirty flames sensor but since you've cleaned it, it probably isn't that. I've seen a faulty wiring harness cause the same issue. I've also seen a customer change out a transformer and not ground the common which caused the issue.

Run a wire from the C terminal on the board to a screw holding the board assembly to the furnace.

Ace hardware will most likely NOT have a flame sensor.

[crays]

Just a thought, based on the manual page you posted. Is your thermostat battery powered, and if so, have you tried replacing with a fresh battery?

In addition to bryj's post, maybe the ground is there but loose?

And I am certainly no expert on the subject matter, just chiming in.

ETA: I originally missed Ray's post regarding the thermostat battery, so I grayed that portion out.

[bellavite1]

Sounds like you maybe lost a ground to the common side of the transformer. The behavior you describe sounds like a dirty flames sensor but since you've cleaned it, it probably isn't that. I've seen a faulty wiring harness cause the same issue. I've also seen a customer change out a transformer and not ground the common which caused the issue.

Run a wire from the C terminal on the board to a screw holding the board assembly to the furnace.

Ace hardware will most likely NOT have a flame sensor.

You lost me at the C terminal...Which one is it?
Are we talking about where the thermostat wires go in?
That's the only place where I see a C marked on the board.
Or by C terminal we are talking about the neutral strip on the left of the board (thermostat wires being up).

[00tec]

Is your thermostat a traditional or one of the "smart" thermostats?

[crays]

You may already have these..

9258092581

[Baetis]

Also check to see that the burners are clean in front of the flame sensor. The board sends a milliamp signal through the flame sensor and to a ground, which should be the burners in front of it. Flame will conduct this signal and gas won?t. That?s how the board knows the gas is ignited, by sensing the completed circuit. When I was in the field anytime I changed an igniter or cleaned a flame sensor I always took out the burners and cleaned them too. I would not use sand paper or like material to clean the sensor as it will start to groove the sensor and stop working well quicker as the junk builds up. I use a steel brush from my cleaning kit. As others have said, it sounds like a poor ground somewhere.


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[bellavite1]

Thermostat is programmable but definitely not smart.

[fitterjohn]

When you pull the thermostat off the baseplate is the ?c? terminal hooked up? I?d make sure all the wires I highlighted are connected, clean your ground terminal the yellow terminal should go to the c on your thermostat 9258292582

[rondog]

Dang, we've been in this house for 20 years and never had any furnace problems. Just change filters.

[bellavite1]

Only two wires between thermostat and board:
Red and white.
It has always been like this.

[bellavite1]

Replaced the flame sensor.
No go.
Looking at the board manual it mentions a potential cause for 8 flashes being terminal C not grounded.
Are we talking about this?
Should i try running a wire to one of the screws on the body?
92583
Like these i.e.
92584

[bellavite1]

And, btw, the moment I put the old flame sensor in it restarted just fine.
Is my furnace allergic to new parts???

[ray1970]

Dang, we've been in this house for 20 years and never had any furnace problems. Just change filters.

Man. I hope you knocked on wood when you posted that.

[bellavite1]

Died again.
Same deal.
Jumped the two thermostat wires to bypass the thermostat and it started working.
Going for a new thermostat.
Maybe I did have two bad thermostats and third time is a charm?[Luck]

[fitterjohn]

Typically c is just a common for a digital thermostat so you don’t have to keep changing the batteries in it.

[fitterjohn]

The symptoms you say lead me back to a flame sensor, it will light a flame and give it a second or two to start generating voltage, when it doesn’t see that it turns the flame off. But the 8 flashes is weird. I don’t think I’ve ever had one give me that. I’d start by making sure your getting the signal you need from the flame sensor, but I’m guessing you don’t have a fluke 87

[bellavite1]

Changed the thermostat and more blinks.
Just added that ground and so far so good (not that it means anything at this point).
Soon enough enough I'll have enough parts to build a second furnace...

[ray1970]

Soon enough enough I'll have enough parts to build a second furnace...

Hey. Maybe when one of them is acting stupid you can use the second one to heat your home.

[SouthPaw]

Same issue happened with a friends furnace. I cleaned the flame sensor with a dollar bill (not to abrasive) and it fired right up. We ordered a replacement, swapped it when it came in, and kept the old as a spare.

[bellavite1]

Update:
I now have the following into this:
New thermostat
New wiring
New flame sensor
New igniter
New pressure switch

It is still giving me trouble.

According to tech support they "think " it maybe the inducer motor starting to die, although the amps reading was excellent.
Replacing it would cost another $475.

The furnace is 17 years old, so, no thank you.

I can have a brand new Armstrong installed for $3500.
Is that an OK price?

About $550 dumped into this piece of crap...

If anyone can use any of the above parts, they were all purchased brand new, for a Goodman furnace.
They have about 40 days of life on them, the board itself less than a week.
I'll give you a good deal.

[eddiememphis]

What model furnace? Do you have central A/C?

A new 80% or 94% will take a bit more work to install than simply replacing an old unit.

If you don't have central air, it's a good idea to install it now. They are running pipes and drilling holes regardless so it may be time to upgrade.

When you sell the place, you will be glad you did.