Oil burner shuts off after a few minutes, blower remains on.

PA1018

Hi, searched thru the logs and could not find this issue so posting in hopes someone has experience with this. Some background... Oil forced hot air furnace in older home. Furnace itself is roughly 10 years old. Was serviced a couple months back and they replaced the ignitor (spelling?) as the arc was getting short causing the unit to not start consistently. Unit was also cleaned, filter replaced etc. Repair man seemed very competent. Problem is its Sunday and I cant reach them.

So during the night I noticed the blower was on for what seemed like a long time. Finally got my lazy **** out of bed to find it blowing cold air. So here is the issue. Beckett burner turns on, nice flame, runs for maybe a few minutes and the burner shuts off while the blower stays on. I checked the Cad Cell, looks like brand new, also checked the resistance with my meter and a flash light... resistance went from essentially open to near zero with the light on the unit.

Can it be the relay itself is not staying open and if so how do i test this. Photo of burner attached.

Thank you for any suggestions.

rick in Alaska

With that primary control, you can push the reset button for a second after it starts running to check the cad cell resistance. Push the button and release it, and the light will flash 1 to 4 times. Count the flashes. If it is 4, the cad cell is reading a high flame signal, which could be a bad fire, a bad cell, or the control is reading wrong.
You can not test the cell with a flashlight as you are not reading what you need to , which is the flame quality.
If you are getting 4 flashes, I would try replacing the cell first. But my suggestion is that you need to get someone with instruments out to look at it in order to do a proper diagnosis.
Rick

PA1018

Hello Rick and thank you for your suggestion. I will give it a try!