Atwood water heater problems

[mike6904]

I have a GC6AA-10E water heater that stopped working, won't work on elect. or gas the gas will light but goes right back out. The tank is full of water. Could it be the thermostat?

[MSHappyCampers]

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

I would doubt that it's the thermostat. I'm no expert on water heaters but I would think there's a control board there somewhere. It probably requires 12VDC to operate so a LV fuse could be blown.

Good luck, happy trails, and God bless!

[Ljwt330]

Originally Posted by mike6904

I have a GC6AA-10E water heater that stopped working, won't work on elect. or gas the gas will light but goes right back out. The tank is full of water. Could it be the thermostat?

The fact that the gas will light indicates that you do have 12v going to the heater. Whether or not that power is consistent, is another issue which may be a problem with the control board, as mentioned. You need 12v power for both electric and gas operation so a faulty board or bad connection is a possibility.


Some questions.

Have you checked that the igniter is properly in the flame of the burner?

Is the tip of the igniter free of soot and rust?

Have you checked and cleaned the connection of the igniter to the control board?

Have you checked/cleaned the orifice of the burner? What color is the initial flame that shortly turns off?

Did the failure to operate on both gas and electric happen suddenly and at the same time, or had you been operating on one source and when it failed tried the other?

Do your other gas appliances work properly, ensuring that all air is out of the lines?

Are you sure the water in the tank is cold (just have to ask?)

When was the last time the heater operated on electric?

Have you tested for 120v at the heating element or ON/OFF switch?

Lots of possibilities out there before your worry about the thermostat.

[Old-Biscuit]

'10E' Version uses common DC circuit for controls/functions
Both AC & GAS send DC to circuit board (White/AC & Orange/GAS)
Then DC from Brown wire (Top connector) goes to T-stat then 'thermal fuse' then back to circuit board via Brown wire (Bottom Connector)

DC then goes to ECO/Gas Valve via RED wire and at same time when on GAS the High Voltage is sent to Spark Electrode.
SO FAR you have those circuit energized on GAS


Flame Proving must occur within 4-6 seconds or Circuit Board DROPS DC on the RED wire (closing gas valve so raw fuel doesn't accumulate)
Flame proving is via 'rectrification' (Flame generates an AC current---ionization...which gets retrficied into a DC Milliamp current.

Circuit Board senses this milliamp current....w/o it DC gets dropped

Spark Electrode is used in this Flame Proving circuit
ELecrode needs to be 'engulfed' in flame

Electrode needs to be CLEAN-----soot/carbon will inhibit the milliamp signal(clean electrode with emery cloth)
Electrode wie connection needs to be clean/tight at Transformer on circuit board
Cermic Insulator needs to be clean & no cracks (silicone spray on a rag...wipe ceramic down)

ALL connections......
At circuit board and on spade terminals need to be clean/tight
T-stat/ECO terminals should NOT wiggle....if they do that can caus Intermittent connections (Replace with new...come as a set)


As for the electric NOT working....
Uses same t-stat AND ECO circuits which are working for GAS
**ECO Circuit (Red Wire)....when on Electric the DC sent via RED wire is a millivolt circuit so that ECO is part of temp control loop. Loss of that millivolt circuit stops electric heating cycle AND will trigger the RED Fault Light

With DC Circuit working (Brown wires/Red Wire---just like it is for GAS) then DC Voltage is sent to a DC/AC Relay via YELLOW wire
Relay closes and then allows AC Voltage from circuit Breaker to the Element

Common issue is with the AC wire connections ON the DC Relay
They can be melted at relay
Also is a burned out element
**remove wires from element and check continuity
Black to White.......No continuity----bad element
White to element flange---continuity---element shorted
120VAC 1400W element (most any hardware store)
1 1/2" thin-walled 6 point socket to R/R

DC Relay/Element are under protective cover on backside of WH Tank
Check ground wire connection to tank wall....they can break off












JUST a FYI
Look on the circuit board for VENDOR/MFG
Atwood had a slew of bad boards (2016---Sept 2018) that caused Intermittent Issues


You didn't post the year of your RV



The bad boards have 'Zhongding' as MFG
Atwood has replaced those for FREE

[mike6904]

Thanks for the info, I have a 2005 Coachman I have set up in Carrabelle, Fl. I like to fish offshore. I ordered a circuit board for it I'll try when I go back over there maybe a couple of weeks. Again Thanks for the info.

[shootist]

Originally Posted by mike6904

Thanks for the info, I have a 2005 Coachman I have set up in Carrabelle, Fl. I like to fish offshore. I ordered a circuit board for it I'll try when I go back over there maybe a couple of weeks. Again Thanks for the info.

If you have a winterize switch or manual valve it will not stay lit with that switch flipped, I had many a cold shower because I didn't know that.

[aether_one]

Old-Biscuit gave you all the technical info you need.

I'll give you the bottom line.

The control board is bad (known frequent failing item on these Atwood water heaters) - replace it with a Dinosaur board.

[mikeh2obury]

Originally Posted by mike6904

I have a GC6AA-10E water heater that stopped working, won't work on elect. or gas the gas will light but goes right back out. The tank is full of water. Could it be the thermostat?

Just had this problem with that unit on our Coachmen. Turned out to be the electrical board. Ordered one on Amazon, plug and play and had hot water immediately.
Just over $100 and didn’t have to pay someone for evaluation, install and the part. Figure it saved me $200 and the old board was upgraded due to problems the unit has produced recently.

[mike6904]

Thanks for the info changed out circuit board and thermostats, now it works on gas but not on electric. At least I have hot water

[Old-Biscuit]

Originally Posted by Old-Biscuit

'10E' Version uses common DC circuit for controls/functions
Both AC & GAS send DC to circuit board (White/AC & Orange/GAS)
Then DC from Brown wire (Top connector) goes to T-stat then 'thermal fuse' then back to circuit board via Brown wire (Bottom Connector)

DC then goes to ECO/Gas Valve via RED wire and at same time when on GAS the High Voltage is sent to Spark Electrode.
SO FAR you have those circuit energized on GAS


Flame Proving must occur within 4-6 seconds or Circuit Board DROPS DC on the RED wire (closing gas valve so raw fuel doesn't accumulate)
Flame proving is via 'rectrification' (Flame generates an AC current---ionization...which gets retrficied into a DC Milliamp current.

Circuit Board senses this milliamp current....w/o it DC gets dropped

Spark Electrode is used in this Flame Proving circuit
ELecrode needs to be 'engulfed' in flame

Electrode needs to be CLEAN-----soot/carbon will inhibit the milliamp signal(clean electrode with emery cloth)
Electrode wie connection needs to be clean/tight at Transformer on circuit board
Cermic Insulator needs to be clean & no cracks (silicone spray on a rag...wipe ceramic down)

ALL connections......
At circuit board and on spade terminals need to be clean/tight
T-stat/ECO terminals should NOT wiggle....if they do that can caus Intermittent connections (Replace with new...come as a set)


As for the electric NOT working....
Uses same t-stat AND ECO circuits which are working for GAS
**ECO Circuit (Red Wire)....when on Electric the DC sent via RED wire is a millivolt circuit so that ECO is part of temp control loop. Loss of that millivolt circuit stops electric heating cycle AND will trigger the RED Fault Light

With DC Circuit working (Brown wires/Red Wire---just like it is for GAS) then DC Voltage is sent to a DC/AC Relay via YELLOW wire
Relay closes and then allows AC Voltage from circuit Breaker to the Element

Common issue is with the AC wire connections ON the DC Relay
They can be melted at relay
Also is a burned out element
**remove wires from element and check continuity
Black to White.......No continuity----bad element
White to element flange---continuity---element shorted
120VAC 1400W element (most any hardware store)
1 1/2" thin-walled 6 point socket to R/R

DC Relay/Element are under protective cover on backside of WH Tank
Check ground wire connection to tank wall....they can break off

Originally Posted by mike6904

Thanks for the info changed out circuit board and thermostats, now it works on gas but not on electric. At least I have hot water

For the Electric issue....re-read the RED highlighted info

Voltmeter.....with water COLD and electric on/off switch ON check that you have 12VDC on YELLOW wire.
Got 12V DC then need to remove cover on backside of water heater tank and check for AC out of the Relay and to the element.
Check if element is bad.
120VAC thru it
Continuity thru it

ETC