Identified voltage drop issue where do I go next?

Boston0991

I recently have been going through the process of trying to fdisgnois my older ducane oil burner issue of the flame flickering on and off super quickly but never fully shutting off or hitting limit. Happens after the unit is running for about 5 min or so normally.

Today i was able to get my multimeter with clamps on the burners motor. After about 5 min of it running normally the flame started going in and out. As i monitored the multimeter you could see the voltage very quickly dropping to almost 0 and then right back up again as the flame flickered each time.

When this happened i also noticed the tjurnland power venters electrical board makes a pretty loud clicking noise that can be heard right as the flame flickers on and off.

I feel I’m getting closer to finding the issue and atleast can now narrow it down to a voltage issue and not a fuel issue.

Would like to hear from others on where I should go next in diagnosing the voltage drop issue. Thinking it could be one of a few things such as a bad board for the power vent , maybe a bad relay seems they can be replaced on the board , a faulty motor on the burner , or lastly a faulty pressure / vaccum switch. I appreciate the help so far and hoping to finally have some heat and my unit running normal again since the three techs I’ve had out so far tell me it’s ok and to just run the burner as is with the issues I’m having.

Heres a video showing the voltage drop.

https://streamable.com/4du4sa

SuperTech

Is the pressure switch chattering? Is the draft setting on the power venter set correctly? Is the blower wheel plugged up?

EBEBRATT-Ed

Sounds like the power venter is the issue. Put you meter across the pressure switch and you should have no problem when it is closed. If it is chattering you should see voltage bumps. Then track it down from there.

Boston0991

https://forum.heatinghelp.com/discussion/comment/1815317#Comment_1815317

blower wheel is good I checked it just now and replaced it myself end of last season along with the blower motor. Pressure proving switch has no noise coming from it. I pulled it off the unit and ohmed it out as I blew into it and it has continuity. Can they pass a continuity test but still be faulty? I also took the multi meter and checked incoming voltage to the board and that held steady with no voltage drop just steady 116 volts at power vent board. When the flame drops in and out super quickly you hear a click that sound like the boards relay making the noise. Also there is one light not lighting up and when it drops in and out there is a series of lights that are changing. I’m leaning towards a bad board since almost everything else has been checked that’s electrical on this unit. What do you think? I appreciate the help!

Here’s a few videos of what’s going on at the board when the power vent and furnace is running..you can hear when it cuts out momentarily.

https://streamable.com/l9fpoi

https://streamable.com/8p5pb7

https://streamable.com/5vqkej

Boston0991

I agree with you seems like a power vent issue and possibly a bad board at the power vent. I tested the incoming power at the board and it’s getting consistent 116 volts and when the unit goes on and off momentarily the voltage does not drop at the power vents board like it does at the motor on the furnace. It Stay steady the whole time. When the flame does drop out you can hear what sounds like the electrical boards relay clicking at the same time as well as a few different lights on the board going on and off. None of the pattern of the lights when I look up on tjurnlands hs1 documents show what they could mean they don’t match up with any of the fault codes.

here’s a few videos that show better then I can explain. Thanks for the help so far

https://streamable.com/l9fpoi

https://streamable.com/8p5pb7

https://streamable.com/5vqkej