Having some trouble with a hot water unit not firing consistently. Works fine for about 20-30 minutes, then burner exhaust starts blowing grey smoke a little; smoke grows worse until it stops lighting, blowing only smoke. I’ve cleaned up the flow switch, changed burner fuel filter, and checked fuel nozzle (visually looks good as does fuel nozzle filter). Even when lighting, it seems to be smoking a bit. I’m going to replace the fuel nozzle, but it seems that if the problem was the nozzle, wouldn’t the problem be consistent rather than only after running for 30 minutes?
is it a 12v system? Your battery may be weak and not creating a good spark. I Had that issue when i have a 12v system
Yes, but the battery is fine, tested at 12.25v
even if you put a voltmeter on a battery and it shows 12v, under a load the battery may not perform well. If you happen to have a spare battery laying around throw it on there and see what happens
Hmmm, good point. Thanks. But … if the battery dropped voltage causing the burner to malfunction, wouldn’t the battery still be too low after sitting for a bit? The burner seems to fire right up when cold, only to act up after about 20-30 minutes - in the middle of a job, I might add.
12.2 volts is dead. A charged battery is 12.6v. If a vehicle has an alternator it should read about 13.5v
1 Like
I have about the same issue with on me of my hot water machines… I’ve had it into the shop quite a few times and I think we’ve replaced just about everything… let me know if you figure it out. I did replace the battery this spring I’ll have to test and see if it still does that
I switched to a 110v burner in 2020 and have not had any problems. My 12v never worked reliably
2 Likes
Well, I checked it again, and it’s one of the strongest batteries I have at 12.9v.
You need to replace the ignitor. Yours has soft failed.
1 Like
Why do you thing it’s the ignitor rather than fuel nozzle or bad fuel?
when it’s smoking, is the smoke black or white
1 Like
White
@Shine , because the electrodes get wore out and get farther away from each other and won’t light correctly. If you keep dumping raw fuel in there and when it does eventually light with plumes of smoke /aka ,soot, it will eventually soot up the coil to where youll have to pull the whole coil out and de soot, MAJOR PITA ,buy new insulation wrap and re install. We get a beckett tune up kit and new fuel nozzle and replace it all every year. It even comes with a handy gauge,And watch YouTube vids to learn
how to install, All for under $100.
I highly recommend this.
Now it could be 100 other things but since you’ve installed a new flow switch and the battery voltage is good ,its probably time to do a tune up kit. My last time ended up being the thermostat . We checked that by bypassing it. But we’ve got 4 hot machines and they are all equally a pita,but we use them alot all year. Good luck Sir.
I’ve got a nozzle coming - the burner probably only has a couple hundred hours on it, so if it’s not the nozzle I’ll go after the electrodes; hopefully that’s the fix. Just in case, what’s your method for pulling the coil and re-wrapping insulation?
Because it works fine for first few minutes.
1 Like
@Shine .Weather you have a vertical coil or a horizontal, remove the incoming and out going fittings, thermostat wire,skin and old insulation. there should be a threaded hole to bolt in a eye hook or its already installed. Lift out coil. We use a forklift, its not light. A engine picker or lots of friends will do. Apply a degreaser then power wash. You can also run coil cleaner through the inside via 12v pump if scale is present. Let dry.
Reinstall coil, put on new coil insulation, hook up all the fittings,skin etc. Then your ready to roll. Its not a hard job. Just heavy, awkward and a very dirty one.
@Shine that enough hours IMO to install a tune up kit.
Understood, thanks.
Great, thanks for the help!
1 Like
