HVAC problem this morning.

[ponytug]

I am sorry to hear about your issues.

Do you have other gas appliances? Are they working? Have you checked your fuel level?

The igniter has to light the flame, but the thermopile is a sensor that monitors the flame, and if the sensor is wearing out or worn out, it won't generate enough electricity to keep the gas on. In the designs that I am familiar with, you can't easily bypass it, for good reasons.

If your fuel level is OK, and the other appliances are working, you probably need a new thermopile. I keep an extra in stock, for this sort of problem. If you drop a new thermopile in and it doesn't fix the issue, then you know that the problem is in the valve. Valves fail less frequently than thermopiles, but they do fail.

Keep us posted!

All the best,

Peter

 

[dadster4]

Woke up this morning and the furnace was not working anymore. It turned on for a few minutes early in the morning ran for a few minutes (maybe 5) and then turned off. When I turn power off to the furnace and it turn it back on the fans all go and I get a red glow on the ignitor but it doesn't ignite and it turns off after a few minutes. I have taken the flame sensor out and cleaned it. I have also tried bypassing the pressure switch as recommended on another forum. For bypassing the pressure switch I turned off the power to the furnace, disconnected the two wires to the pressure switch. Turn it back on and then connect those two wires together. When I do that the fans are running but I no longer get a red glow on the ignitor.

The pressure switch and all other safeties in the circuit must be connected at initial call for heat...the control board senses that all safeties are closed before starting the ignition cycle.

 

[dadster4]

I am sorry to hear about your issues.

Do you have other gas appliances? Are they working? Have you checked your fuel level?

The igniter has to light the flame, but the thermopile is a sensor that monitors the flame, and if the sensor is wearing out or worn out, it won't generate enough electricity to keep the gas on. In the designs that I am familiar with, you can't easily bypass it, for good reasons.

If your fuel level is OK, and the other appliances are working, you probably need a new thermopile. I keep an extra in stock, for this sort of problem. If you drop a new thermopile in and it doesn't fix the issue, then you know that the problem is in the valve. Valves fail less frequently than thermopiles, but they do fail.

Keep us posted!

All the best,

Peter

FYI to avoid confusion...a thermopile creates a millivolt current which powers the gas valve and requires no 120v to provide heat, not used on modern equipment. A thermocouple (or glow plug type igniter) is what senses pilot flame in modern equipment.

 

[ultrarunner]

The pressure switch and all other safeties in the circuit must be connected at initial call for heat...the control board senses that all safeties are closed before starting the ignition cycle.

Just like tractors and safety switches...

I am spending more maintaining newer furnaces since circuit boards and their sensors came to be... simply more things to go wrong and troubleshoot.

 

[oldnslo]

Woke up this morning and the furnace was not working anymore. It turned on for a few minutes early in the morning ran for a few minutes (maybe 5) and then turned off. When I turn power off to the furnace and it turn it back on the fans all go and I get a red glow on the ignitor but it doesn't ignite and it turns off after a few minutes. I have taken the flame sensor out and cleaned it. I have also tried bypassing the pressure switch as recommended on another forum. For bypassing the pressure switch I turned off the power to the furnace, disconnected the two wires to the pressure switch. Turn it back on and then connect those two wires together. When I do that the fans are running but I no longer get a red glow on the ignitor.

Does your furnace have any LEDs on the circuit board that blink a fault code. Most newer units have this and usually an explanation of the codes is on a decal on the furnace somewhere. These can provide some guidance on potential failing component.

 

[ultrarunner]

In the last 30 days at rentals Ive had a draft motor go out at one place, draft sensor at another and at my home the ignitor went bad... hairline crack I couldn't see until removed... no glow.

I miss the days of pilot lights!!!

 

[TN8Man]

One of the first upgrades to my house was to have a wood burning stove installed. My home is warm in a power outage and I don't pay the high electric bills for heat.

 

[ultrarunner]

Not an option here… even with unlimited oak on property to keep dozens of stoves fueled.

 

[TN8Man]

Not an option here… even with unlimited oak on property to keep dozens of stoves fueled.

I had options when I lived in California ... the option to leave for greener pastures.

 

[ultrarunner]

I’m always amazed at the people who have spent time or have ties to California.

Just about all my Washington State neighbors have California ties even if it was years ago.

Many first came to Washington via military and decided to stay.

Very different than my grade school years when as much as half my classmates were new transplants…