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Any marshian a/c technicians? (1 Viewer)

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steveb

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So I hear draft inducer fan running and see igniter coming on (3 times) but no flame/ignition.

So either the "new" gas valve is bad or maybe something really is up with furnace control board?
 

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well have you YouTubed it, the stereotype is right there is almost every how-to video there
 

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Call me and I will walk you through a trouble shooting process. eight three two-473-4380
 
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Seems I received a bad gas valve.

I am getting 26.2v to the gas valve during the ignition sequence. I’m not hearing or feeling the solenoid click while 26.2v is present.



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steveb

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Just out of curiosity the entire time I have power to the furnace I see 2.x volts AC to the solenoid. Then during ignition sequence after igniter turns on 26.2v At solenoid then drops back to 2.x volts again after a couple of seconds.

Is that normal?


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webster1234

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The 2.x volts you see is feedback or "noise" in the line. When the control board energizes the solenoid, you see the 26v. Then when is senses no flame, it kills the 26v and goes back to the noise in the line. That's normal.
 
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Kinda what I thought.

Was thinking maybe that low voltage might be creating a large amperage that then damages the coil.

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webster1234

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It's hard to damage a coil. It's just an electro magnet. Kind of like wrapping a wire multiple times around a nail in elementary science class. Not much you can do to damage it other than shorting it out or maybe hitting it with high voltage, which would overheat the wires and cause them to melt or short out. A voltage lower than the rated voltage shouldn't affect it.
 

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So what all have you checked?

In my experience the gas valve is usually towards the end of my diagnosis. Have you checked the limit switches?

Also check your igniter. It will still send voltage for a min. Or even light with a small crack in it depending on which one you have, but will not send the amperage to open the gas valve.

I would check to make sure you have continuity through all your safety switches. I will be off around 4-5ish if you need some help over the phone. 985 373 7459

We need to get a marshian face chat thing.
 
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I have not.

When there is a call for heat

Exhaust inducer motor starts. After a minute or so the igniter turns on. Then a few seconds later I see 26.2 volts at the gas valve. Then a few seconds later the igniter turns off.

It repeats that same cycle two more times with the igniter on a little longer each time.


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Check your igniter.

Take it off and check for very small cracks. It will probably look like a whitish line going across. You can also check to see if it to see if it has continuity. But that is not always a tell tale sign. They are pretty cheap I would just change it out.

Next I would check the limit switches. Let me know how it goes?
 
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Replaced the replacement gas valve. No Joy.

995dfe04b6625f41121ffed8cee05c91.jpg
 

Cody

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Replaced the replacement gas valve. No Joy.

995dfe04b6625f41121ffed8cee05c91.jpg
When you posted this earlier, the technician was finishing getting mine back up and running. Survived on a floor heater for the bedroom and a lot of wood for the fireplace. Thanks to @reeftopia for hooking me up with a steal on year old, dry live oak! Filled up the back of my car and it kept the house warm!
 
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steveb

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It was the control board. It was sending 24v to the gas solenoid but apparently wasn’t able to allow enough current to trip it.

Fired right up after I switched it out.
 

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It's hard to damage a coil. It's just an electro magnet. Kind of like wrapping a wire multiple times around a nail in elementary science class. Not much you can do to damage it other than shorting it out or maybe hitting it with high voltage, which would overheat the wires and cause them to melt or short out. A voltage lower than the rated voltage shouldn't affect it.

Thanks @webster1234
Ac went out lucky for me it was just the capacitor. I’m glad to have a reefing/and ac tech friend like Webster [emoji4][emoji106][emoji4]
 

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