New owner with "pilot out" mystery

[Pelledan]

This is indeed perplexing. The fact that the unit works fine on propane, but does so on electric for only 60 minutes before going into fault is a head scratcher. On one hand it points again to the ECO-STAT. The STAT is not cutting the fuel when it's preset high temperature is satisfied, so the ECO takes over when the temperature exceeds its preset internal limit and cuts the fuel activating the fault. The only way to reset is for the tank temp to fall below the ECO's upper limit and the STAT's high temp setting then cycle the on/off switch to reset the fault which allows the heating cycle to begin again until over temp again causes the shutdown. If the ECO and STAT are still the problem, then the propane fuel would be subjected to the same series of events that causes the electric fuel to fault as it too uses the same safety components that electric does. Yet the propane fuel works fine. The electric heating element appears to be fine as either they work or they don't. Process of elimination then leaves the circuit board as suspect?
Dan

[Kg4izw]

You have explained things very clearly, so clearly in fact that I realize I may have not been as thorough in my testing as I have previously believed.
I do not believe I have left the propane heating on long enough to test the fault light since replacement of the stat and Eco. When I use propane, I heat the water enough to take a shower and then immediately shut it down.
I will try testing the propane side and leave it on a few hours this time to test again for the light.
Your description was very helpful.
Thanks.

[Kg4izw]

Well it has been well over two hours and the propane is heating the water without the red fault turning on.
What is my next move?

[Pelledan]

Like I said before, this is perplexing. The fact that the propane works says the ECO-STAT are not the problem. The fact that the heater works on electric for an hour before triggering a fault says that most likely the electric heating element is fine. That leaves only two component suspects. There is a relay in the heater that has a 12 volt DC controller that switches the 120v AC electric heating element on. If that relay has a poor electrical connection on the contacts that transfers the 120 volts, it MAY be heating up and causing the fault due to higher than normal amperage consumption. I THINK that relay is in the back of the heater. The only other component is the circuit board itself. At this point it may be more beneficial to call in a mobile tech to troubleshoot. The circuit board is relatively expensive and needs to be replaced only if PROVEN defective. A properly equipped tech will have a circuit board tester that will check that. The relay is inexpensive, but getting to it may be difficult. Maybe someone else on this board can chime in with other ideas or solutions?
Dan

[Kg4izw]

I have been reading other postings on older Atwood water heaters (mine is a 2004) and i read that older Atwood units had the propane Eco and tstat on the front and electric Eco and tstat on the back.
This would explain a lot though.
There has to be a way to find out without removing the entire unit.

[Old-Biscuit]

Originally Posted by Kg4izw

I have been reading other postings on older Atwood water heaters (mine is a 2004) and i read that older Atwood units had the propane Eco and tstat on the front and electric Eco and tstat on the back.
This would explain a lot though.
There has to be a way to find out without removing the entire unit.

Simple......just access backside and LOOK
But all you will see is a protective cover over electric element and relay

2003 and prior version had separate t-stat & ECo for electric (on backside) and propane (on frontside)
This is a GC10A-3E.....simple connections on circuit board as it only controls propane


You have a 2004 version. GC10A-4E
Electric and propane use SAME front mounted t-stat and ECO, DC controls and combined circuit board
This is what your Atwood 10 gal looks like.....dual connectors on circuit board...bundle of wires (white, orange, yellow, blue, brown, green, red)


As I mentioned in earlier post......
The RED wire from circuit board gets a MILIVOLT signal to ECO, Thru ECO to gas valve solenoid and to ground when using Electric heating.
This is so the ECO is a functioning part of the circuit.....safety feature
so that ECO can shut down heating should the t-stat NOT control as designed.
T-stat should OPEN at 140*F and CLOSE at 110*F to control heating cycle
ECO OPENS at 180*F to STOP heating cycle before temp goes to high
(T&P Relief Valve is final backup---Opens at 210*F/150 psi)

Propane using FULL 12V DC Voltage while heating.
12V DC from ON/OFF (orange) to circuit board, on BROWN wires (thermal fuse, t-stat) RED wire to ECO, to gas valve solenoid (Opening gas valve)

Electric only uses FULL 12V DC from ON/Off (white) to circuit board, on BROWN (thermal fuse & t-stat) and on the YELLOW wire to relay.
(IF 'relay' was issue you would not get FAULT Light....all that would happen is NO electric heating)
Then it is MILIVOLT signal to ECO/gas valve----just enough to function but not enough to open gas valve

IF that MILIVOLT signal is NOT coming from circuit board, NOT going to/thru ECO then FAULT
Even IF ECO is NOT opening (t-stat not opening) you will get FAULT Light if MILIVOLT signal is not leaving circuit board.

Normally the issue would be t-stat not opening and water getting TOO hot
Doesn't sound like that is the issue
So that points back to connections on circuit board OR electric circuit on board that triggers the Milivolt signal to RED wire

Measure water heater temp at end of heating cycle (propane AND electric)
and see IF different temps are happening OR if temp is going to high???


Best replacement board is a Dinosaur Electronics .....better quality and good pricing
Your Atwood board 93851 would be replaced with a Dino UIB 64 board
UIB 64 page

E-bay has it for $102.75....new board and protective cover
Dinosaur Electronics UIB 64 PC Board for the Atwood Water heater | eBay

[Kg4izw]

Well I figured a workaround:
If I heat the water with propane, turn propane off, and then turn on the 120v water heater, it is able to maintain the water temperature without tripping the fault.
It can recover from washing dishes, washing hands, etc without tripping the fault. The only thing it can't do is recover from a shower with hot water. It flips the fault light and shuts down. But all I have to do is turn the switch off and then back on (not the breaker) and it stays hot again.
I am going to live with this for a while.
I have this metal smell in my hot water that I need to figure out next before I spend any money on this water heater. I may need to replace it anyway if I can't get rid of the smell.
Thanks for all the help.

[Old-Biscuit]

How about measuring the water temp.....

On propane when it shuts down

And on electric .....deplete the hot water (shower etc) then turn electric on.
When you get FAULT then measure temp

Measure temp of hot....
Open hotside of nearest faucet, let run then collect hot in glass jar, cup etc and measure temp with thermometer

On propane OR electric hot water temp should be close to 140*F (+/- 5*F)
when normal heating cycle is completed (20-30 minutes unless supply water temp is very cold)

Temp of water will tell you IF water heater is functioning correctly

Post temps..

[Kg4izw]

Well my problem has not gone away, only worsened.
Without going into too much detail, it is looking like the control board. The board is over $100, but an entire new unit is only around $500. And ALL the parts on my current water heater are 13 years old and showing their age. I think I will replace the entire thing so I only have to deal with this one more time. My question: Is there a new version of the GC10A-4E model 94022 or 94018?
It looks like one version has these four silver looking "L" brackets on the front.
Is there any advantage to this version?
Any disadvantages? like wiring, fitment, propane connections, flame adjustment, etc.

I am going to need to start learning more about this.