Case of the intermittent flame failures

This is not a single case but rather some common causes I have found for intermittent flame failures over the years. An intermittent problem is the most annoying type of service call. I'm sure you will have other experiences and would love hearing yours.

[@Hearthman1159]

Good stuff Ray. I use a circuit analyzer to detect excessive line voltage drop and resistance. Kudos to considering all the other factors besides the flame proving system itself. Most techs in residential just replace boards and flame rods over and over. It may have been inadequate inlet pressure/ pressure drop from skinny piping or a clogged valve. My favorites are venting obstructions and dropouts when other appliances come online. I use that rectification jumper to verify the electronics. Most rectification problems I see are due to distortion of the pilot flame and poor ground. I see cheap solderless ring terminals corroded- use original Thomas & Betts Sta-Kons. Scrape the mating surface clear of paint or powdercoating. Keep the CAZ clear of chemicals and dust. I've seen dusty fireplaces continue to have problems until the combustion chamber is vacuumed. Where the ground plane includes the pilot burner, torque the mounting screws as these may have been left loose when the last parts changer replaced the assembly. Other issues include testing the line voltage neutral to ground for less than 50 mv, xformer line to primary hot phasing, and plugged heat exchanger/ venting. Thx for sharing.

[@boilerroomdetective]

Wow I will have to include these on the next intermittent flame failure followup video I appreciate it.We have become a change and replace industry. I used to rebuild pneumatic controls when I was an apprentice

[@lnk4328]

All good points Ray. For forced draft boilers, the three top reasons for pilot failure are: #1, Dirty pilot, #2, Too much pilot gas pressure, #3, Not enough pilot (low fire) air. Modern techs sure have it a lot easier than us old timers that had to contend with vacuum tubed flame safeguard controls with no diagnostics. I remember that we used to build our own "mouse traps". A box with latching relays and lights that we temporarily wired into the customer's burner panel that would at least allow us to see if the lockout was pre-ignition, pilot or main flame.

[@boilerroomdetective]

Yes sir thanks for your top 3 list. I did have one of those "mouse traps"we made and used a lot. LOL As far as easier, I am not sure about that. While many devices have on board diagnostics, the moodiness of control boards is often tough to troubleshoot. Thanks again and have a great weekend

[@JohnDoe-ej1lw]

Good video Ray....always learn something new from your videos 👍

[@boilerroomdetective]

Thanks I learn something new every day in this industry Enjoy your weekend

[@l.crossjr]

This is gold. Enjoying your books too

[@boilerroomdetective]

Thank you so much I appreciate it

[@CommercialGasEngineerVideos]

Love the intro

[@boilerroomdetective]

Thanks Its a work in progress. Have a great weekend

[@NROhvac]

I’ve had to tighten wiring connections before

[@boilerroomdetective]

It's amazing what a loose wiring connection does. I have drilled it into my son and he tells every contractor to do it for the boilers we sell

[@christopherleubner6633]

Make sure to check for corrosion as well.

[@boilerroomdetective]

@@christopherleubner6633 Good point I could do a whole booklet on intermittent flame failures I think

[@christopherleubner6633]

I had a case like that and the infrared thermocouple that senses the main burner light was loose on the BCM simply tightening the screws on the probe snd she lit right up. Happened at a motel in Wisconsin in the middle of winter 😳

[@boilerroomdetective]

I'll bet you were the hero that night. I dread this calls at night in the middle of winter

[@christopherleubner6633]

@boilerroomdetective yup it was about 10pm and the guests were noticing as the outside temp was 22 below. 🥶

[@marriagepartnersministry5942]

I got an intermittent flame failure problem several years ago. I tried everything. after several visits the customer was so mad at me that they hired another company. There wasn't a pressure switch issue but the other guy took apart the chimney to find a partially collapsed chimney that was causing the intermittency. He got lucky and I lost the contract.

[@boilerroomdetective]

Ouch that hurts He did get lucky probably because of the ground work you did