Community Forums

Fireflies · 07-22-2018, 11:33 PM

Hi Guys

I have a problem with my Atwood water heater on my RV cutting out every 20-30 secs
I've only had the RV a few weeks and are some distance from the dealers here in the UK and are due to return there in a few months to touch base with them

I'd like to perhaps sort the issue myself if I can

The water heater ignites OK and roars furiously at various tones then slowly dies away and eventually stops. This is on a regular 20-30 sec cycle and will do this for about 15mins until it runs evenly. Constant igniting of the bolier can't be doing it any good

The heater dates back to 2007 but has seen very little use in that time

Any ideas please?

Pete

Old-Biscuit · 07-23-2018, 11:47 PM

Dirty orifice, burner tube, combustion/exhaust chamber would be place to start

Little use means bugs/insects/spider webs etc

So remove ignitor assembly...clean it off using emery cloth

Remove burner tube...clean it out using small bottle brush. Check that the flame spreader plate is parallel with end of burner tube

Remove orifice...screws into gas valve---soak in alcohol then blow dry (low air pressure so the orifice hole is not damaged....no poking things thru it either)
Run wire thru combustion chamber and out exhaust side...tie rag to wire and pull it back thru (chimney sweep)
\
Put it back together and give it a try.
When it lights off...adjust air shutter (plate on burner tube with slots) so flame is BLUE with slight roar

IF Flame still peters out.......LP Regulator is not keeping up with demand

SuperGewl · 07-24-2018, 12:24 AM

How does the stove flame look and act? If it acts the same way as the water heater the look more towards the regulator and or the propane itself.

Fireflies · 07-24-2018, 12:35 AM

Quote:

Originally Posted by SuperGewl

How does the stove flame look and act? If it acts the same way as the water heater the look more towards the regulator and or the propane itself.

Hi SuperGewl. All is fine at the stove with constant blue flame of good strength

I’m gonna do what Old-biscuit says and strip it down. I think that this would probably not have been done by the dealer if it worked OK after being left on to test and inspect later as it gets better once warmed up and guess they didn’t spot it at PDI

Old-Biscuit · 07-24-2018, 05:50 PM

Good flames at stove top is NOT a true indication that main LP Reg is holding/maintaining correct system pressure

Stove/oven uses its own reg for burners.
System pressure S/B 11"WC.......stove/oven reg is 10" WC
11"----0.4 psi
10"----0.36 psi
Hard to visually see 0.04 psi difference

IF system is only 10" stove/oven can still function properly BUT water heater will not due to low system pressure.

Manometer is what is used to prove LP Reg is holding/maintaining system pressure under demand

ftodaro · 07-24-2018, 07:12 PM

atwoodwaterheater.pdf

You can start throwing parts at it. A friend just went through this. He put in a new flame sensor then put in a new circuit board. It did not fix it. Took it to a local guy who replaced the new circuit board. His comment was that he did not have good luck with Atwood circuit boards. They cost about 100.00 for that part. There is an Atwood repair manual see above.

SuperGewl · 07-24-2018, 11:53 PM

I think you are best to go ahead and break it down and clean the gas tubes properly and then reassemble it and adjust it and see if things are better.

sfergie631 · 07-25-2018, 05:19 AM

Quote:

Originally Posted by ftodaro

Attachment 212278

You can start throwing parts at it. A friend just went through this. He put in a new flame sensor then put in a new circuit board. It did not fix it. Took it to a local guy who replaced the new circuit board. His comment was that he did not have good luck with Atwood circuit boards. They cost about 100.00 for that part. There is an Atwood repair manual see above.

Thanks for the troubleshooting manual-great to add to the “hope I never need it” archive!