[Drider75]

I have been trying to get some help fixing this POS for 2 months now - I live in AZ, so its not like we're freezing to death but it has been damn cold a few nights.

Well anyway, I troubleshot it for a few hours, replaced the fan board and got nowhere. I decided to let the "pros" handle it, well two technicians came out from two different companies (they both sucked) the furnace was working when they left, but an hour later it quits.

Its a Heil / ICP / Tempstar mounted horizontally - its an 80% eff unit, conventional burner, draft induction - pretty much the same furnace put into every cookie cutter tract home in the US.. this should not be rocket science.

The furnace simply will not start, no draft inducer, nothing. When power is cycled on and off a dozen times quickly, on a rare occasion, it starts, then runs for an hour - that is pretty much what happened both times the techs came out.

We have spent 5 hours troubleshooting, in addition to having the two aforementioned techs out here. I am pretty much one step away from taking a louisville slugger to this lousy piece of crap.

1> New fan board installed 12.6 - its not that
2> Tested all limit switches - zero ohms and continuity circuit is complete
3> Ignitor functions fine, it was firing when furnace did start
4> Checked 24 V transformer - good
5> Replaced intermittent ignition control module - another $150 down the toilet - still did not fix problem.
6> Checked all wires, re-seated all connections
7> Checked door interlock, thinking it might be intermittent, we bypassed it.
8> Checked inducer - fine
9> Checked vacuum switch - fine
10> Thermostat bypassed - its not that
11> Air condition works



The only electrical thing that has not been replaced is the gas valve- even if that was dead the freakin inducer should should still spin right - at least that is what the factory Heil tech said ? The burner might not fire but the inducer should still start...

I don't get it... we've blown $500 on this hunk of garbage and we're still not fixed. I design and troubleshoot jet engines for a living, certainly this is not rocket science..

You'd think people who do this stuff for a living would have found it, but nope. So now - what's next ?? Replace a $400 gas valve and pray ? I could have damn near bought a new furnace now.

Any ideas, I'm all ears....

 

[Doc Holliday]

uhm, stat? remove the face plate of the stat or simply turn the stat off and on the control board in the furnace jump r-w to bring on heat. If that works, remove those jumpers and do that at the stat. does that work, each time?

 

[HvacWiz]

Quick question to you, does this furnace have a standard gas valve or a honeywell smart valve?

 

[Drider75]

uhm, stat? remove the face plate of the stat or simply turn the stat off and on the control board in the furnace jump r-w to bring on heat. If that works, remove those jumpers and do that at the stat. does that work, each time?

Thanks for asking the obvious question though... we get pilots who say engine start failed, and they never turned on the fuel... even smart people make mistakes..
We did cover that base thoroughly !

Stat and circuit fine, we bypassed it completely to rule it out.

 

[Drider75]

Quick question to you, does this furnace have a standard gas valve or a honeywell smart valve?

Its a standard gas valve, part # 1005597

On a good note, I was able to find one new from Midwest HVAC for $115...

 

[how]

As Doc says...Jumper R & W on the furnace (stat lines removed) to eliminate a stat issue.

Can you measure if the board supplies 120V power to the ID assy?

Is there an led light on the board that gives a fault diagnosis?

I'd only change that valve if you can confirm it's getting 24V and not opening. Besides, everything starts with the inducer's operation so you kind of have the cart before the horse.

 

[kirwinjd]

I have been trying to get some help fixing this POS for 2 months now - I live in AZ, so its not like we're freezing to death but it has been damn cold a few nights.

Well anyway, I troubleshot it for a few hours, replaced the fan board and got nowhere. I decided to let the "pros" handle it, well two technicians came out from two different companies (they both sucked) the furnace was working when they left, but an hour later it quits.

Its a Heil / ICP / Tempstar mounted horizontally - its an 80% eff unit, conventional burner, draft induction - pretty much the same furnace put into every cookie cutter tract home in the US.. this should not be rocket science.

The furnace simply will not start, no draft inducer, nothing. When power is cycled on and off a dozen times quickly, on a rare occasion, it starts, then runs for an hour - that is pretty much what happened both times the techs came out.

We have spent 5 hours troubleshooting, in addition to having the two aforementioned techs out here. I am pretty much one step away from taking a louisville slugger to this lousy piece of crap.

1> New fan board installed 12.6 - its not that
2> Tested all limit switches - zero ohms and continuity circuit is complete
3> Ignitor functions fine, it was firing when furnace did start
4> Checked 24 V transformer - good
5> Replaced intermittent ignition control module - another $150 down the toilet - still did not fix problem.
6> Checked all wires, re-seated all connections
7> Checked door interlock, thinking it might be intermittent, we bypassed it.
8> Checked inducer - fine
9> Checked vacuum switch - fine
10> Thermostat bypassed - its not that
11> Air condition works

The only electrical thing that has not been replaced is the gas valve- even if that was dead the freakin inducer should should still spin right - at least that is what the factory Heil tech said ? The burner might not fire but the inducer should still start...

I don't get it... we've blown $500 on this hunk of garbage and we're still not fixed. I design and troubleshoot jet engines for a living, certainly this is not rocket science..

You'd think people who do this stuff for a living would have found it, but nope. So now - what's next ?? Replace a $400 gas valve and pray ? I could have damn near bought a new furnace now.

Any ideas, I'm all ears....

So it starts working again for a while after you disconnect and reconnect the power?
If so, I'd keep the interlock switch bypassed so you could check all the controls while its still calling for heat but not working.
I know you checked the inducer motor but did you check for voltage going to it immediately after it quit working? Any possibility that the inducer motor is overheating then slows down or seizing up, cooling down then running again? The very first stage is the inducer motor. Nothing will happen until the IDM starts and closes the pressure switch. With R and W jumped at the board, that is the place to start.

What about the two companies who came out? Won't either one of them return and stick with it until the problem is fixed?
They shouldn't be charging you cent until its fixed. I will not accept payment from my customers until I've fixed it right and If I don't then I will set up camp in their attic if necessary until I find the problem.

 

[Drider75]

Not sure why everyone is suggesting the thermostat - we've already connected R&W and completely bypassed the t-stat. It is definitely not the stat or anything related to it.

T-stat works fine for A/C before we bypassed it.

We have two of these furnaces - as a "just in case" I took the t-stat from the bad one, tried it on the good one and it worked fine.


Inducer motor itself is fine, I applied 24V directly to it, it will run forever if I wanted it to... it is not the motor.

The board is getting 24V, it is not a power issue.


I am pretty well versed in how this unit operates, that is why it is so frustrating. I have done everything that has been suggested here already, the only thing I do not have is access to the detailed schematics so I cannot see exactly how the sequencing goes or what dependency the entire system has on the gas valve.


I am under the impression that this is not a "smart" furnace - therefore, when the t-stat calls for heat, assuming all the limit switches are good, the fan timer board will start the inducer motor first no matter what - the inducer motor will create a negative pressure in the flue, upon which the vacuum switch will close, allowing the ignition sequence to start.

If the gas valve or ignitor were bad I would think that the inducer would still start run for 30 seconds (or whatever the value is set on the timer board) and then shut down. In this case, we get absolutely nothing.

It actually is acting like the limit switch somewhere is bad, but we tested the ALL and they are continuous.

I have owned 5 homes, I have been able to fix and troubleshoot every heating and a/c issue I have ever ran across - including just about every one of my neighbors - this POS is beyond stumping me, and its probably the most simple system I've ever had.

I simply do not get how the inducer won't start when all the electronics have been replaced.

And as far as companies standing by their work - this is Arizona, we have lousy contractors here, no one stands by their work, that is why I do everything myself.

 

[beenthere]

That gas valve part number is not Honeywell's part number. Post the Honeywell number, or pic of the gas valve. You probably have a smart valve(more commonly known as a dumb valve). And this is one of the things they are known to do.

 

[HVACTECH96]

How was pressure switch checked?Sucking on tube and hearing click doesn't count.Some units wont work if pressure switch is in a closed position on call for heat.I've seen them stick intermittantly.Also have seen alot of heil's get moisture buildup in pressure switch hose.

 

[HVACTECH96]

You could test this theory by jumping pressure switch out before you have a call for heat and see if you get same no id motor.If id motor comes on , remove jumpers and bang head on furnace.

 

[ben's plumbing]

you say you have a 24v inducer motor on that heil furnace .what is the complete model number..so we can fix this thing...ben sr

 

[ben's plumbing]

Not sure why everyone is suggesting the thermostat - we've already connected R&W and completely bypassed the t-stat. It is definitely not the stat or anything related to it.

T-stat works fine for A/C before we bypassed it.

We have two of these furnaces - as a "just in case" I took the t-stat from the bad one, tried it on the good one and it worked fine.


Inducer motor itself is fine, I applied 24V directly to it, it will run forever if I wanted it to... it is not the motor.

The board is getting 24V, it is not a power issue.


I am pretty well versed in how this unit operates, that is why it is so frustrating. I have done everything that has been suggested here already, the only thing I do not have is access to the detailed schematics so I cannot see exactly how the sequencing goes or what dependency the entire system has on the gas valve.


I am under the impression that this is not a "smart" furnace - therefore, when the t-stat calls for heat, assuming all the limit switches are good, the fan timer board will start the inducer motor first no matter what - the inducer motor will create a negative pressure in the flue, upon which the vacuum switch will close, allowing the ignition sequence to start.

If the gas valve or ignitor were bad I would think that the inducer would still start run for 30 seconds (or whatever the value is set on the timer board) and then shut down. In this case, we get absolutely nothing.

It actually is acting like the limit switch somewhere is bad, but we tested the ALL and they are continuous.

I have owned 5 homes, I have been able to fix and troubleshoot every heating and a/c issue I have ever ran across - including just about every one of my neighbors - this POS is beyond stumping me, and its probably the most simple system I've ever had.

I simply do not get how the inducer won't start when all the electronics have been replaced.

And as far as companies standing by their work - this is Arizona, we have lousy contractors here, no one stands by their work, that is why I do everything myself.

goggle heil furnaces ..should be able to get diagrams and flow charts..ben sr

 

[ben's plumbing]

take a picture of unit with door off so we can see the inducer,pressure switch,and gas valve ....if you get us the things I ask for...we will fix this unit..ben sr

 

[bobinphx]

What about the two companies who came out? Won't either one of them return and stick with it until the problem is fixed?
They shouldn't be charging you cent until its fixed. QUOTE]


HVAC people in phoenix are not like elsewhere. The city is so big that they can hack and hack and never be out of work. That is not to say that there are not some really great Pro's out there, but they are few and far between!!!!!!!

look up thermalmedic and give merrit a call, if he cant do it, he knows someone who can.

 

[Drider75]

take a picture of unit with door off so we can see the inducer,pressure switch,and gas valve ....if you get us the things I ask for...we will fix this unit..ben sr

Thanks Ben!

I don't have a photo handy, but click the link below to the manual / parts blowup for the exact model I do have - it also has illustrations.

NTG3/FBF

If you still want a photo, I will make the time to get one.

I have already replaced item #6, Part #1011927
and #6A, Part #1011449

The gas valve is a honeywell part # VR8204M1075

clients.6ixgun.com/L0502532.pdf

Currently the unit has the door interlock and thermostat bypassed (i.e. - hard wired to call for heat and bypass door safety ).

 

[Drider75]

That gas valve part number is not Honeywell's part number. Post the Honeywell number, or pic of the gas valve. You probably have a smart valve(more commonly known as a dumb valve). And this is one of the things they are known to do.

Honeywell part # VR8204M1075

 

[Drider75]

How was pressure switch checked?Sucking on tube and hearing click doesn't count.Some units wont work if pressure switch is in a closed position on call for heat.I've seen them stick intermittantly.Also have seen alot of heil's get moisture buildup in pressure switch hose.

We connected an ohm meter to it and took a reading, sucked on the pressure tube and it changed state. I assume its supposed to be open when there is no draft vacuum, and closed when an adequate amount of vacuum is present.

The switch appeared to work as intended. It looks like new, no corrosion any where and the inside of the tube is spotless.

 

[jagans]

Im not a pro like some of the others here, but did the installer comply with the installation instructions completely? Heil Furnaces cam be installed in a number of configurations but some cannot be installed horizontally. Is your model no correct for the application? In addition, you have to relocate the pressure switch on some models for the furnace to work properly, and clearances seem to be pretty important.

Having the furnace dead level also seems to be important. Is it?

Just some thoughts to consider. In general Heil furnaces seem to be nicely designed from an engineering standpoint. Maybe its a basic installation problem.

Check out page 7 of the manual you posted.

 

[Drider75]

Im not a pro like some of the others here, but did the installer comply with the installation instructions completely? Heil Furnaces cam be installed in a number of configurations but some cannot be installed horizontally. Is your model no correct for the application? In addition, you have to relocate the pressure switch on some models for the furnace to work properly, and clearances seem to be pretty important.

Having the furnace dead level also seems to be important. Is it?

Just some thoughts to consider. In general Heil furnaces seem to be nicely designed from an engineering standpoint. Maybe its a basic installation problem.

Check out page 7 of the manual you posted.

Furnace is 10 years old, it was installed right and had been running fine. Definitely not the issue.