thermal coupler


  #1  
Old 10-01-03, 11:46 AM
bonnie burgess
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thermal coupler

My heater would work fine, then the blower would remain working with cold air coming out, but the pilot light would go out.
If I relit it, the burner would come on, the same thing would happen, work fine for awhile, then the pilot light would go out.
We replaced the thermal couple, but now the pilot light will work, but the burner will not light. We put the old one back on, and the burner will still not light.
It is a Bryant unit, installed 8 years ago. The switch is on, I've done the pilot instructions, over and over. The thermostat is on auto, and we turned the heat up to make it come on, but it doesn't work. Any suggestions?
Thanks
 
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Old 10-01-03, 11:54 AM
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Was the gas valve turned from "Pilot" to "ON"?

if so and the pilot is still on. then you want to check to make sure you are getting 24volts to the gas valve on the call of heat.

make sure the power (breaker, or switch by furnace it turned on).. I've heard it happing when people forgot to turn them back on after trying to light the pilot
 
  #3  
Old 10-01-03, 11:55 AM
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heat

Do you know if you have 24 volts power to the gas valve there?The valve It is turn to on now right and the tstat is on and calling for heat pushed up high. ED
 
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Old 10-01-03, 12:01 PM
bonnie burgess
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To Ed and Jay,
Thanks for your response. The pilot is "on". The switch is "on".
I don't know how to check the 24 volts. Sounds like something a professional needs to check.
I just think it's strange that the burner used to come on until we changed it.
Bonnie
 
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Old 10-01-03, 12:14 PM
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Bonnie,

do you have a volt meter?

Put the meter probe on both term on the gas vave, and you should get 24volts on call of heat.

if you are getting 24 volts, then the gas valve needs to be replaced.

if you are not getting 24volts, then trace back to the fan/lmiit switch on on till you get 24 volts.

Also make sure your blower door is on right! :-)
 
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Old 10-01-03, 12:14 PM
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heat

Could you have a wire off there at the valve? ED
 
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Old 10-01-03, 12:16 PM
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LOL you beat me to it, Ed.. I just thought of the wire after I sent the post..

Looks like you and I have nothing else going on today.. hehe :-)
 
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Old 10-01-03, 12:20 PM
bonnie burgess
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Thanks, Guys,
My Dad has a volt meter he's bringing over to check it. I did put that blower door on, but maybe I didn't do it right. Didn't think it was too big of a deal. I will check the wires to it also, and get back with you.
Thanks a bunch.
Bonnie
 
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Old 10-01-03, 12:56 PM
bonnie burgess
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OK, Ed and Jay,
We're both kind of clueless on this volt meter, but we put it on what I think is the gas valve (it says 24v on the box), and put the other end below the box, and it says 24v. That is if I'm looking at the right part of the meter, which it says AC10v in the red line on the bottom.
I don't know which wires to check either. Still I think it's strange that the gas valve is bad when it worked before we changed it. But you certainly know a lot more than me which isn't much here.
What do you think? Thanks again,
Bonnie
 
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Old 10-01-03, 01:10 PM
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Depends on what Scale you set the meter on..


So if you put the meter on the gas valve the stamped "TH" and "TR" you read 24 volts, then it's a bad valve.
 
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Old 10-01-03, 02:08 PM
bonnie burgess
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Ok,
So I measured it again, with the setting OHM X1K, and the TR measured 12 and the TH measured 10. That's again if I measured it right. We tried to measure with ACV and it did nothing.
BB
 
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Old 10-01-03, 02:20 PM
bonnie burgess
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We measured it wrong. Now we put both connectors on each side of TR and TH and they both measured 21.
Bonnie
 
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Old 10-02-03, 09:06 AM
bonnie burgess
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So, does the TR and TH measuring 21 volts each mean a bad valve, it definietely doesn't measure 24 volts. Is it something else? Remember it used to work before we changed the thermal couple. I checked the wires to make sure they are secure. I checked the breaker for the furnace. Nothing still happens.
BB
 
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Old 10-02-03, 08:34 PM
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Yeah if your getting power reading at the valve.. so, yes the valve is bad...

Double check to make sure your knob is changed from "PILOT" over to "ON"
 
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Old 10-02-03, 09:41 PM
bonnie burgess
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Ok, Thanks, Jay,
So I'll call in a professional to change that. So why does the burner not work now, when it worked before we changed the thermal coupler? It lit just a couple of days ago just fine. The pilot light just kept going out, but I could always relight it. Coincidental? And yes, I did make sure the pilot was turned to "on." Anyway thanks for your help. I appreciate it.
Bonnie
 
  #16  
Old 10-06-03, 04:23 PM
bonnie burgess
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FIY, if anyone wants to know. It was just a fuse.
 
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Old 10-06-03, 04:44 PM
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Just a fuse?


What fuse? What was it fused on to?

If it was just the fuse, then you would of not gotten any power at all to the gas valve...
 
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Old 10-06-03, 04:53 PM
bonnie burgess
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I don't know where it's fused to. I read about fuses, but I didn't see any place a fuse could be. It was in the section underneath where another door was that can be taken off.
It works fine now-lit right up. Took the guy 5 minutes for $70 bucks.
 
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Old 10-11-03, 03:06 AM
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Pilot keeps going out

Check that you do not have a crack in the heat exchanger. If the fire lights up ok and then goes out a few minutes later when the circulating fan starts up I would wonder if the fan is blowing though the crack into the combustion chamber enough to snuff the pilot. Just a thought
 
 

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