furnace blower stuck running

[AC/DCdude17]

I've a gas furnace of unknown make, model and have an AC installed as well. It connects to a thermostat through a four wire configuration. The whole setup is about 13 years old. The thermostat have three settings like the average thermostat. A/C(Red, yellow and green shorted), heat(red, white and green shorted) and there's a switch labeled auto/on that let's you turn on the blower manually(red and green shorted).

Every once in a while, furnace blower keeps running after turning off after using fan only and only when I use fan only. I thought it was a problem in the thermostat, so I pulled it out of the socket. Fan continued to whir.

I measured the voltage across green and red and read 24V as the fan continued to run, so it's clear that there isn't a short in control wiring.

To shut it off, I'll have to short red and green a few times with a paperclip at the thermostat socket and fan eventually turns off.

If I don't do this, it contiues to run forever. I can also do the same shorting technique to get the blower stuck running. My assumption is that pulsating the control terminals turns it off by jiggling the stuck terminals apart.

Is there anything I should suspect beside the mechanical relay?

[donald girod]

If there's a relay to control the fan motor, then that's the problem. Sometimes the control is solid state, but in any case, that's where the problem is.

[Noon-Air]

You should suspect that we can't tell you anything about your system without seeing it. Make/model/serial numbers help, but still not enough information. You shou should also suspect that you will find a local, *competent*, licensed, professionally trained, HVAC technician in your Yellow Pages.

[TAB Dude]

Could be a couple of things. You need a meter. If no meter call a tech.

TAB Dude

[kjpro]

In favor of the OP.

Read the post again.........he measured the 24v across the stat wires. So, I believe he'd have to have a meter. :-)

-- kjpro _-~-_>_-~-_>_-~-_>_-~-_>_-~-_>_-~-_>_-~-_>_-~-_>_-~-_>_-~-_>_-~-_>

( kjpro @ starband . net ) remove spaces to e-mail

Want it done yesterday? Or done right today, to save money tomorrow!!

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[TAB Dude]

Your right... A Good multi meter. The conditions you describe is indeed a control issue, but most likely not your t-stat. you will need a meter that will do milli amps. At best you will isolate the fault, see a burnt contact and say "Oh!". More likely you will narrow the problem down to two possible issues. At this point you will call atech or change parts. If you have a $10.00 analoge meter from Sears, it will not do. Happy hunting!

TAB Dude

[AC/DCdude17]

If my intention was to make someone else rich, I would have already done so. Thanks for your pointless advise.

[Joseph]

You wanted advice, you got advice, you didn't like advice, too bad... The reason you got that advice is from your post the problem is obvious and it should already be fixed. since you apparently can't see that; you should put down the meter and call a tech like he said. This is not a slam it is meant to help. some of the things you can destroy playing with it like a toy could cost substantially more.

Joseph

[Noon-Air]

I guess he failed to read my sig file

[CBHvac]

.Clueless garbage about an unknown unit snipped.

Let your fingers do the walking and locate someone in your area that knows what in hell he is doing?

[kjpro]

Oh, bright one, tell me how in the hell that the fan/limit control is going to fix this guys problem.

Be very specific, so we can tell how it's related to the relay that is likely going BAD!

Oh, you can't tell us.........eh? Then STFU!!

Goodbye. :-)

-- kjpro _-~-_>_-~-_>_-~-_>_-~-_>_-~-_>_-~-_>_-~-_>_-~-_>_-~-_>_-~-_>_-~-_>

( kjpro @ starband . net ) remove spaces to e-mail

Want it done yesterday? Or done right today, to save money tomorrow!!

_>_>_>_>_>_>_>_>_>_>_>_>_>_>_>_>_>_>_>_>_>_>_>_>_>_>_>

[Oval]

Sorry for the snips and dip.

In respnose to THIS:

If my > I've a gas furnace of unknown make, model and have an AC installed as > well.

I have useless advice, and not even the solution, so we're on a good start already.

Sounds old already, most AC units have thermostat wire running to the equipment. We are still working on wireless stats.

So you saying you have a dead short between R-Y-G standard circuit for cooling? If it was short then it would be off, hence "short".

Heat---hmmmm R-W-G standard config for heat? Again with the shorting..I hate short's, how bout you?

Oh yeah , thats what I would have done...

Yes, thats why it's usually printed on most 24VAC transformers..uh....24VAC

Oh yeah, Thats would I would have done.....

That the best diagnosis I have heard all week. Noth> You shou should also suspect that you will find a local, *competent*,

If my intention was to make someone else rich, I would have already done so. Thanks for your pointless advise.

No you need to call someone in the phone book under"A", for Air Conditioning. Or what I should do is tell you what's wrong and let you spend twice the amount of money at Radio Shack and Home Depot?

Have a nice Day? Oval

[Oval]

Yet another:

"I sec> Oh, you can't tell us.........eh? Then STFU!!

[Noon-Air]

Consider this "drivel", *anybody* that messes with a safety limit switch that obviously doesn't know what it is or what it does, needs to get his head examined.... because now not only has he voided *any* warrenty that might be on his furnce, but has also voided his homeowners insurance. You must have been blessed at birth to be able to take chances like that with your home and your family's lives.

The advice I gave is correct, and I still stand by it. If you choose to ignore it, then the consequences are on you.

[Mike Simpson]

Bullcrap....please quote the appropriate section of *any* homeowners policy in the USA that applies....

didn't think you could.......

ms

[Tim or Marty Shephard]

I'm gonna have to agree with Mike...why would the mortgage company require the insurance if it didn't protect them against owner's stupidity? Also, how would the investigator be able to tell an adjustment wasn't made by a "local, *competent*, licensed, professionally trained, HVAC technician in your Yellow Pages".

policy in the USA that

[Mike Simpson]

Just as an aside....how many auto policy claims would be paid if "stupidity" was a legitimate exclusion?? ;-))

ms

[CBHvac]

policy in the USA that

Farmers, in NC...since non licenced persons are NOT allowed to repair, or service HVAC products... Thats per NC law BTW...

Oh..you want a quote from the policy...

Damage to Heating, Cooling, Heat Pump, Furnace, or related ductwork in relation to said system will not be covered by any section of this policy if said system is not maintained by a licenced person or corperation.

What in hell is it with you people? Do you think we make this shit up? Funny...as long as YOU can fix it, or think you fix it, we are dumbasses...but let one thing come along that you cant fix, and you bite the bullet... Next time, think about that and fix it your damn self.

Have a great day..

[LS]

I didn't say what he did was smart, I was just commenting on your childish response.