Ruud furnace cycles then shuts off

underlandtongue

Basics: Ruud furnace circa I have no clue
Ignition: Electronic
Condition: System cuts off during cycle.

The system will ignite the pilot, flood the burner with gas and ignite, warm the system up, the blower starts and everything seems to be going well then...

...it shuts off.

At first we thought it might be the stack control reading that it's hotter than it actually was...but it won't turn back on all night.

Only when I blow some air at the pilot do I get the system to kick back on and continue it's cycle.

So, I've read about the flame sensor but frankly after reading a post in one of your forums a bit scared to do it. (Ruud furnace issue on upgrade board and flame sensor)

yuri

Post some pics of the unit with the front and lower doors off so we may identify it. Click "go advanced/manage attachments".

underlandtongue

underlandtongue

underlandtongue

underlandtongue

yuri

That unit is at least 25 yrs old and in fair shape. May need a new pilot burner and flame sensor and control board due to the age and rust. Uses flame rectification to allow the burner to run and I cannot explain all that to a DIYer. I would recommend a new furnace as the heat exchanger may be cracked or crack soon. With the government rebates now is a good time to buy.

underlandtongue

Thanks Yuri. The photos are deceiving, there is very little to no rust on the unit. Most of that is/was dust as we completely cleaned out the unit. After a cleaning off the pilot and flame sensor, it runs great.

Now, if we can just get the door to fit right so that the shut off switch will stay on.

yuri

Make sure you have 2 NEW CO detectors in your house. 1 in your bedroom, 1 in the stairwell from the basement. Glad you got it going.

Use some strong duct tape or silver self adhesive duct tape to hold the door on.