Atwood water heater won't stay lit.

[Leardriver]

Originally Posted by nvs4602

I'll ask the dumb question. Is the hot water heater full of water with the air bled out of it?

Funny you should ask. I am just coming inside from solving the problem, and saw your post.

Problem solved!!!

Pure operator error.

I pulled the heater tank drain plug out again, and only got a trickle of water, not the 4 gallons I suspected.

Hmmm. The water pump is on, and the water heater bypass valve that I have been staring at for days is in the correct position....but it wasn't! The tank was mostly empty. If only someone would design a system that shuts it off when it got too hot....

The ECO was doing it's job precisely, because it was too hot in the partially empty water tank.

I am re-labelling the confusing normal/bypass valve so that a numbskull like myself can't even screw it up.

SO, nothing was ever broken, I got a great lesson in how that system worked, did a spring parts replacement tune up, and if I get to use it again this year, I will have to find something else to mess up. It was only staying lit for 3-4 seconds at first, so I probably replaced a failing part along the way. I keep telling myself that.

Thanks to all who helped.

[nvs4602]

A lesson well learned from my dad was to always check the easiest things first.

[Deep Water D]

Good to have spare parts on hand!

[Old-Biscuit]

Glad controls were doing their job.


Sounds like you lucked out and had enough water to keep electric element from burning out (they don't last long dry firing)




Don;t understand you DC Voltage readings
BRN 3, White 2, OR 1


I get White 2/OR 1
That is DC from electric (white) and gas (OR) on/off switches to circuit board


BUT BRN 3???
With electric or gas on DC from circuit board goes thru thermal fuse to t-stat via BRN 1 (bottom connector)
With t-stat closed DC goes from t-stat back to circuit board BRN 3 (top connector)


Can't have DC on BRN 3 and No DC on BRN 1.......
CAN have DC on BRN 1 and No DC on BRN 3 when T-stat opens


T-stat should have opened when tank got hot
ECO wouldn't open until tank got HOT-HOT (180*F) and it would have triggered the RED Fault Light plus locked out any attempts to refire w/o reset


????

[Old-Biscuit]

Originally Posted by Old-Biscuit

Glad controls were doing their job.


Sounds like you lucked out and had enough water to keep electric element from burning out (they don't last long dry firing)




Don;t understand you DC Voltage readings
BRN 3, White 2, OR 1


I get White 2/OR 1
That is DC from electric (white) and gas (OR) on/off switches to circuit board


BUT BRN 3???
With electric or gas on DC from circuit board goes thru thermal fuse to t-stat via BRN 1 (bottom connector)
With t-stat closed DC goes from t-stat back to circuit board BRN 3 (top connector)


Can't have DC on BRN 3 and No DC on BRN 1.......
CAN have DC on BRN 1 and No DC on BRN 3 when T-stat opens


T-stat should have opened when tank got hot
ECO wouldn't open until tank got HOT-HOT (180*F) and it would have triggered the RED Fault Light plus locked out any attempts to refire w/o reset


????

Forget about DC statement in above that I have struck.
Had my thinking cap on backwards
(Sometimes I get dyslexic)



DC comes from On/Off Switches via White 2 (electric) or OR 1 (gas) and goes to Tstat via BRN 3

With Tstat closed DC goes thru thermal fuse and back to Circuit Board via BRN 1


T-stat opens DC on White 2, OR 1 AND BRN 3 would be normal

[imnprsd]

Many thanks to everyone who contributed to this post.

I will keep it in my library for the day I need help understanding how my hot water heater works.

Thanks!

[Soflotony1]

Make sure your replacement part works. I checked continuity and voltage on circuits as mentioned before. Found brand new replacement control/spark ignitor/sensor board was bad. Board could not sense flame was lit and kept turning off gas control valve.

AUTOBABA 91365 Circuit Board (Amazon) $48 - DID NOT WORK.

Atwood 91365 Circuit Board Kit for Water Heaters (Amazon) $88 - Use with Gas/Electric 12 VDC - Atwood Store - Worked 1st time !!
https://www.amazon.com/dp/B019COT1HC...fed_asin_title

38' 2005 Monaco Knight , South Florida
Kept me in hot water with the wife ! All good !
Soflotony