Carrier gas furnace blows cold air

[tepolt]

Hello All,

This is my first post here. I am a Home Do-it-yourselfer-So be gentle...

My 10-12 year old Carrier gas furnace (Model # 58ED 050131CA) has had an intermittent problem. It will blow warm air for a few minutes until house is up to the set thermostat temperature, then after the flame is out the blower keeps going until I turn the tstat down all the way. When reset with tstat it will work for a couple cycles then do the same thing. Last Fall it did the same thing and I found that the electronic igniter plate was carbonized. I removed the carbonization and it has worked for 5 months. Do I need to replace this plate or is it another part such as a sensor or circuit board that I need to look into?

Any suggestions are welcome-thanks!

 

[glennjanie]

Welcome Tepolt:
Yes, I would replace the igniter plate and see what happens. It couldn't cost as much as a service call.
Carrier (as far as I know) was first to use the computer boards in their units, which means you have to replace the whole board in the area affected. I didn't like to work on them.
Glenn

 

[user 4883]

Is there a time delay for the blower motor and it's sticking?
Is there a temp sensor not realizing it's time to stop blowing?

 

[tepolt]

Well, I found that the igniter and the sensor are one in the same and that the electrode was carbonized again. I cleaned for now to test-if this is it I may not replace it since there's only one more month or so of heating. Though if I need on, I see they go for around $21 on the web. Thanks for the help.

 

[user 4883]

If it is the type of ignitor/sensor that I'm familiar w/, you won't want to touch the ignitor w/your fingers, it will cause a hot spot on it.

 

[tepolt]

Thanks for the tip!