Foretravel Owners' Forum

Foretravel Motorhome Forums => Foretravel Tech Talk => Topic started by: Tim on November 29, 2018, 05:02:38 pm

Title: Rapid Carbon Buildup on Electrodes
Post by: Tim on November 29, 2018, 05:02:38 pm
See photo. The Atwood hot water heater failed to ignite. Carbon was building up quickly on the electrodes for the electronic ignition. So I just cleaned and gapped (1/8 inch) electrodes last week. The propane flame looks normal because there was just a few yellow tips on the flame.

I have since replaced the electrodes and ignition module, so we'll see if this fixes the problem. I am just curious how carbon could build up so quickly on the electrodes.
Title: Re: Rapid Carbon Buildup on Electrodes
Post by: wolfe10 on November 29, 2018, 05:12:14 pm
Running rich will cause that. Dirt, debris or insect next in the "U" tube will cause that.

First thing I would do is used compressed air to blow out the "U" shaped burner tube.  Be sure to stand beside the water heater when you do it so you don't get a face full of dirt.

Less likely if all other appliances are working correctly is high propane pressure.
Title: Re: Rapid Carbon Buildup on Electrodes
Post by: Pierce & Gaylie Stewart on November 29, 2018, 05:48:53 pm
After Brett's suggestion, check the air slider to make sure the screw has not come loose. This can cause a rich mixture. Any yellow other than orange and yellow flashes in the flame means it's generating carbon monoxide and is a rich mixture.

Have you observed the arc from the electrodes when the heater is trying to light?

Pierce
Title: Re: Rapid Carbon Buildup on Electrodes
Post by: DavidS on November 29, 2018, 06:44:41 pm
Glad I have an Aquahot ;D

just wanted to throw that out there ... Just kidding.. I heard  in the last few days that there is never a problem with the propane heaters.. guess they were not correct.



in its defense I never had an issue with my propane on my trailers and very minimal issues with my aquahot , mostly maintenance and upkeep..
Title: Re: Rapid Carbon Buildup on Electrodes
Post by: Caflashbob on November 29, 2018, 07:19:59 pm
Fixed a lot of propane heaters long ago as a Foretravel manager.  No aqua hots installed in the 80's and early 90's

If it's got parts it will need fixing.  Duh.

Title: Re: Rapid Carbon Buildup on Electrodes
Post by: Old phart phred on November 29, 2018, 09:59:38 pm
Near as I can tell my water heater, and one furnace are 29 years old and still working.
Title: Re: Rapid Carbon Buildup on Electrodes
Post by: Tim on November 29, 2018, 10:27:21 pm
Thanks for the tips.
All screws were and are tight. If the flame shape and tip looks normal; blue with with some occasional small yellowish flashes, this shouldn't foul the electrodes, yes?

I will blow compressed air tomorrow.

BTW, Aquahot is maintenance-free, yes?  ;)
Title: Re: Rapid Carbon Buildup on Electrodes
Post by: Caflashbob on November 29, 2018, 10:54:40 pm
The  perfect machine has no moving parts. Quote from "childhoods end" by Arthur Clark
Title: Re: Rapid Carbon Buildup on Electrodes
Post by: Tim on November 30, 2018, 05:29:37 pm
The propane hot water heater has one moving part: the gas solenoid. How many moving parts does Aquahot have? Just curious.
Title: Re: Rapid Carbon Buildup on Electrodes
Post by: craneman on November 30, 2018, 06:40:03 pm
The propane hot water heater has one moving part: the gas solenoid. How many moving parts does Aquahot have? Just curious.
How many moving parts does your coach heating system have? AH is both
Title: Re: Rapid Carbon Buildup on Electrodes
Post by: Roger & Susan in Home2 on November 30, 2018, 08:23:20 pm
You don't have an AH Tim.  What's your point? When my AH is on 120v heat has one pump, two heat exchanger fans in the LR. That is all we need.  No additional parts to create all the hot water we need too.  And it makes no noise to annoy your neighbors like an LP water heater and LP furnace make.

Be happy with what you have.  I am. Don't complain about what you don't understand and what you don't have.
Title: Re: Rapid Carbon Buildup on Electrodes
Post by: NancyS on November 30, 2018, 08:32:27 pm
Word of advise, Whole House Propane Regulators have a life span of 10 years per our dealer.  Soot build up can be from in proper pressure adjustment, or stale propane. If you have gas delivered to your coach ask the delivery guy about having the service guy come out and check your pressures, they usually do it for free.
Title: Re: Rapid Carbon Buildup on Electrodes
Post by: Old phart phred on November 30, 2018, 09:15:44 pm
Just curious about the AH, does it also exchange heat from the engine while driving?
Title: Re: Rapid Carbon Buildup on Electrodes
Post by: Pamela & Mike on November 30, 2018, 09:26:46 pm
Just curious about the AH, does it also exchange heat from the engine while driving?
Yes
Mike
Title: Re: Rapid Carbon Buildup on Electrodes
Post by: Tim on November 30, 2018, 09:29:43 pm
Hmmm, the propane tank dial says it is just below 1/4 tank. That should leave about 10 gallons of propane left. Shouldn't that be enough LPG to provide enough pressure? I plan on filling it up next week.

Don't get me wrong, I am a fan of Aquahot, but it is quite complex. It would be nice if I was a full-time RVer.
Title: Re: Rapid Carbon Buildup on Electrodes
Post by: Roger & Susan in Home2 on November 30, 2018, 10:24:10 pm
Drive, heat the AH from the engine, heat the coach while on the way.  Hot water when you get somewhere,  no diesel, no electric and still plenty of hot water in the morning.
Title: Re: Rapid Carbon Buildup on Electrodes
Post by: wolfe10 on December 01, 2018, 09:23:02 am
Hmmm, the propane tank dial says it is just below 1/4 tank. That should leave about 10 gallons of propane left. Shouldn't that be enough LPG to provide enough pressure?

Yes, as long as there is liquid propane, gas (vapor pressure) is sufficient.  Remember, it is reduced to under ONE PSI by the regulator.
Title: Re: Rapid Carbon Buildup on Electrodes
Post by: amos.harrison on December 02, 2018, 06:16:21 am
But tank gauges are notoriously inaccurate.
Title: Re: Rapid Carbon Buildup on Electrodes
Post by: wolfe10 on December 02, 2018, 09:04:13 am
If the stove and furnace work normally, assume propane in the tank is not the problem.