Atwood water heated will not stay running.

Keith, I have the same WH in my truck camper, and started a Tech Issues topic on 3/4/19 regarding a similar problem I was having.

Atwood Water Heater Problem

At the time of my last post, I thought we had the problem licked, but the T-stat/ECO turned out to NOT be the source of the problem. Mine is shutting off, and then immediately turning back on before the water is fully heated up. It does that several times before finally shutting off for good when the water reaches 140*.

After replacing the T-stat/ECO switches, and confirming the problem still exists, I tried cleaning the connections again but that didn’t help. I eventually discovered that I could cause the WH to shut off/on by tapping on the igniter board with a screwdriver handle. In fact, one component on the board appeared to be especially sensitive.

Anyway, I ordered another igniter board and I wanted to pass along some info that may be of help to you. I was told that Dometic bought Atwood, and now Dometic is doing things differently with the parts. When you bought a new igniter board from Atwood, they included an adapter plug that converted the edge connector on the older WH’s to the pin-type plug on the new igniter boards. Now that Dometic is supplying the parts, that little $2 adapter plug has to be purchased separately. I’m currently waiting on an adapter plug to be shipped so I can finish fixing my water heater. :M

I’ll update my topic once I get the new igniter board installed.

:):)

thanks old biscuit ,you always have great advice. and how to check it out.

Thermal Cut Off is a 'One Shot Fuse'...BLOWS at 190*F and MUST be replaced.
Blow back from combustion chamber trips it.

The Zhongding circuit boards are faulty......and as of Sept 2018 should NOT be available. Atwood got rid of them, notified Dealers and Vendors to do the same.

No 'thermocouple' used on OPs model. Electronic Ignition which also is used for flame proving )Spark ELectrode)


Run for 10 minutes or so.....
Fault Light comes on-----
2 things trigger fault light
*Loss of Flame Proving signal----bad/dirty spark electrode, cracked ceramic insulator, dirty loose high tension wire/wire connector, loss of ground
*ECO (Energy Cut Off--HI Temp T-stat) opening (180*F---so water should be very hot cause T-stat failed to open at 140*F), bad/dirty-loose spade connectors

***Bad circuit board can cause either of the 2 items that trigger Fault Light

How old is it?

If newer look for this on the control board and if it's there call Atwood, they'll send you new board.

Perhaps the "thermal cut-off device"? (on the incoming power wire and is connected to the thermostat) If there is an obstruction in the burner or flue tube (mud wasps, eg) it will trip. Also the exhaust grill on the access door must be clear or it can trip the thermal cut-off. The wide band on the grill must be at the bottom. If at the top, pop it out and put it in right way up.

I am not a RV tech but it does sound like a bad thermocouple.

don,t no much about them ,but it has a thermocoupler on it it could be going bad.