Atwood propane hot water heater

[sleeeper]

I recently purchased a 1999 Winnebago Adventurer 37G. The hot water heater would only run for 4 min and shutoff. I have cleaned the tank and replaced the thermostat and eco switch. I have replaced the 4 wire ends on those switches. I have cleaned the terminals on the circuit board. I have swapped out the circuit board with another known good board. I have run a tip cleaner through the gas jet. Cleaned the gas tube and blown compressed air thru the chamber. The tank is full of water and the pump is on. Cleaned the ground wires and run additional ground jumper wires. The heater starts up on the first spark and now runs for twenty minutes and shuts off. Cycling the switch inside and disconnecting and reconnecting the circuit board connector fails to reset the heater. Sits overnight and it will restart the next morning for 20 minutes. ,the water is hot for about 20 seconds after the heater is running for 20 min. Have a nice blue flame. It is a gas only heater. Any help is appreciated in advance.
Thanks
Patrick.

[Old-Biscuit]

OK.....
1st off NEVER poke anything thru the orifice.
It is a metered hole that allows the gas flow to mix with the air so the correct air/fuel ratio is achieved.
You state you have a nice blue flame so it sounds like you got away with it...this time.
Remove and soak in alcohol then air dry (no high pressure air either)


2nd.....
Water heater now runs for 20 minutes /shuts down and you get hot water flow for about 20 seconds.
Does the water continue to flow and just turns warm/cold
OR
Does water flow STOP????


20 minutes of operation is roughly the right amount of time to heata 6 gal tank of water to 140*F (set point of t-stat)
20 seconds on hot then warm/cold flow--------
Check that showers (inside/outside) are turned off using the cold/hot knobs and not just the button on shower handle
If just button on handle----shower faucet becomes a mixing chamber and cold can flow into hot water lines


Flow STOPS.....
THen check valve in HOT out is jclogging/jamming up


Water Heater heating BUT not coming back on.
Water temp has to drop below 110*F before T-stat will close for reheat cycle
If water in tank still hot...no reheat cycle cause t-stat not calling for it


Swapped circuit boards....
Could still be a faulty circuit board
Depending on which version/vendor board you are using




What model is your Atwood.......G6a-8E by chance?
What is the Vendor on the label on that circuit board??

[speed racer]

Does it have a water heater bypass. This could be set for bypass. The water heater should have a one way check valve. Is it in the correct place and is it working.

[MSHappyCampers]

Hi ! Welcome to IRV2! We're sure glad you joined the gang!

Noticed you are kinda new on IRV2 and wanted to say hello! Listen to Old Biscuit, he gives great advice! Have fun and keep her between the ditches!

Good luck, happy trails, and God bless!

[Deep Water D]

My bet is that you mixed up the thermostats. It heats the tank but goes out on eco rather than cycling on the normal thermostat.

[sleeeper]

Thanks for the reply speed racer. I am traveling this weekend and when I get back I will check under the sink for a bypass and also let some water out of the relief valve and see if is consistently hot. I think you on to something since there is nothing else to check out. Thanks

[Old-Biscuit]

Originally Posted by Deep Water D

My bet is that you mixed up the thermostats. It heats the tank but goes out on eco rather than cycling on the normal thermostat.

T-stat and ECO sit side by side'
Measure same tank temp'


T-stat IF functioning will OPEN 1st regardless of which position it is installed


ECO terminals/RED spade wire connections are larger then the T-stat terminals/Brown spade wire connections



Even If you installed the RED wires on the T-stat.......heating would be shut down when t-stat opened

[Deep Water D]

They can be switched despite the difference in terminal sizes. Fleetwood did that to mine. So if the lower temp stat is in the wrong place, it will open first and put the unit in ECO.

[sleeeper]

Originally Posted by Deep Water D

They can be switched despite the difference in terminal sizes. Fleetwood did that to mine. So if the lower temp stat is in the wrong place, it will open first and put the unit in ECO.

Thanks to old biscuit and deep water. I paid particular attention when I installed the new stat and eco switch. When I bought this bus it was still winterized. I am thinking that the hot water bypass valve was never turned back to normal use. I am going to check that first and if that is not the remedy I will look into those switches being reversed. Thanks to all who submitted ideas. They were all good ones and I will report back next week.

[Ray,IN]

Originally Posted by Deep Water D

My bet is that you mixed up the thermostats. It heats the tank but goes out on eco rather than cycling on the normal thermostat.

Terminals are different sizes/widths, no way to switch them. I just returned from going to the garage and trying to switch the Atwood terminals on the 'stats. It would be a miracle if terminals got switched on the wiring while my MH was parked in my locked garage, and it worked fine in June.
I'm having the same problem. I have accomplished every test in the Atwood service manual except gas pressure test. LP lights immediately, burner runs for 4 seconds and goes out like gas valve closed, and lockout light comes on. My model # is Atwood GCH10A-3E if you can assist either sleeper or myself. In fact, replacing the gas valve is my last old part.
Deep Water, just how can the 3/16" narrow terminals be forced onto the 1/4" wide terminals???

[Old-Biscuit]

Regardless of WHICH position the t-stat or ECO is in....
T-stat OPENS at 140*F
If it is in the ECO position so what....it is still going to stop the DC to gas valve be at the ECO red wires OR at the T-stat Brown wires.
DC Circuit is interupted.


ECO does NOT open until 180*F




Sleeper.....
You failed to answer ANY questions I posed.


Ray, IN...sent you a PM

[Det57]

Hi Old Biscuit.... Need some opinion here please....


I have a (new to me) 2000 Fleetwood Discovery with a G10-3E (Gas only) water heater.

I replaced the circuit board, thermostat, ignitor, on this heater when I bought the coach last October, as preventative maintenance, so I had fresh everything in it.

It was running great until about two weeks ago. Now.... I turn it on and after about 3-5 seconds I get ignition failure light in the cockpit. It tries three times and each time the fail light comes on...

I hear a click back at the heater when the switch is turned on...…. but the ignitor never fires or even attempts to. I believe I do smell propane so I am getting gas...
Ive cleaned all contacts including ground wire...
Could my (new) circuit board be bad again? Thoughts.

[speed racer]

Originally Posted by Det57

Hi Old Biscuit.... Need some opinion here please....


I have a (new to me) 2000 Fleetwood Discovery with a G10-3E (Gas only) water heater.

I replaced the circuit board, thermostat, ignitor, on this heater when I bought the coach last October, as preventative maintenance, so I had fresh everything in it.

It was running great until about two weeks ago. Now.... I turn it on and after about 3-5 seconds I get ignition failure light in the cockpit. It tries three times and each time the fail light comes on...

I hear a click back at the heater when the switch is turned on...…. but the ignitor never fires or even attempts to. I believe I do smell propane so I am getting gas...
Ive cleaned all contacts including ground wire...
Could my (new) circuit board be bad again? Thoughts.

This sounds to me like the flame indicator is not working and the circuit board doesn't know it lit.

[Old-Biscuit]

Originally Posted by Det57

Hi Old Biscuit.... Need some opinion here please....


I have a (new to me) 2000 Fleetwood Discovery with a G10-3E (Gas only) water heater.

I replaced the circuit board, thermostat, ignitor, on this heater when I bought the coach last October, as preventative maintenance, so I had fresh everything in it.

It was running great until about two weeks ago. Now.... I turn it on and after about 3-5 seconds I get ignition failure light in the cockpit. It tries three times and each time the fail light comes on...

I hear a click back at the heater when the switch is turned on...…. but the ignitor never fires or even attempts to. I believe I do smell propane so I am getting gas...
Ive cleaned all contacts including ground wire...
Could my (new) circuit board be bad again? Thoughts.

1st off
Oct of last year you got a new circuit board.
From 2016 thru Sept 2018 Atwood had faulty circuit boards from a different vendor they tried.
By Sept of 2018 Atwood factory & dealers had new stock.......aftermarket still had defective boards in stock.
Yours could be from that bad batch.
Check the bar code label on circuit board and see IF it is 'Zhongding' if so contact Atwood and inquire....they may send you a new board FREE







Course even if not a Zhongding board could be defective.


Sparl Electrode NOT firing....
*Wire connection AT transformer loose, dirty/corroded
*Wire not connected inside the ceramic insulator (broken off from electrode rod)
*Too narrow/too wide gap (1/8" - 3/16")
*Ground issue......spark electrode assembly mounting screw is ground source. Screw needs good clean/tight connection


Circuit Board....
Spark Electrode & gas valve get DC Voltage at same time
Gas Valve via RED wire

Spark Electrode via the transformer tower wire cnnection


Use BBQ lighter and see if you can light flame when someone turns Switch ON


New spark electrode is inexpensive to try.
But no sparking is most likely bad circuit board