2004 Vectra-Water Heater-OK Gas, Not AC

[viktor]

Friends: My water heater has decided to not work on AC. More accurately, it works sporatically. It works fine on propane. About 10 ohm resistance on heating element. I replaced the thermostats. The ECO was going from 0 to 10 ohm resistance so I replaced both. Still have the same problem. All connectors are clean and the fuses are OK. I have power to the inside switch and the breakers are not tripped. Any thoughts?

[Old-Biscuit]

Would that be an Atwood Brand?

Model?

2004 was crossover model year
Could be gas/electric with separate controls---8E (6gal)/3E (10 gal) version
Could be gas/electric with common controls---10E (6al)/4E (10 gal) version

different response vs which version

[emiddleb]

There was only one OEM water heater on the '04 Vectra - Atwood 10gal with Motorade. My model is the GCH10A-4E. Of course, after 18 yrs, he might not have the original water heater.

OP, what's your power source when you have the issue? By any chance are you on 30amp service? Wondering if your Energy Mgmt system is shedding the water heater.

Other than that, you seem to have checked everything I would do at first glance.

[Old-Biscuit]

That's why Year/Brand/Model are important

If that is the case......GC10A-4E (GCH10A-4E)
T-stat/ECO are common to gas & electric operation
Thermal Fuse is common to gas & electric operation

When on electric:
12VDC to on-off switch then to circuit board via WHITE Wire
With T-stat closed (temp below 110*F) 12VDC goes to DC Relay Via YELLOW Wire
DC Relay Closes allowing 120VAC from circuit breaker to go to element

*DC Fluctuating on Yellow wire.... 6 pin connector loose, grounds loose/bad or circuit board fault
*DC constant on Yellow wire....DC Relay issue/relay failing or AC wire to/from relay bad

[viktor]

10 gallon

[viktor]

Thanks to everyone that responded. If I leave the interior swith ON it will eventually heat the water maybe every other day. I have ordered a new circuit board. Everything else seems OK. Keeping fingers crossed, but not holding my breath.

[Old-Biscuit]

Did you measure the DC Voltage on the YELLOW wire when using the AC Element?

Did you do any testing?

[viktor]

Getting back to you. Brutal winter here caused a delay in getting back to the heater problem. Tested White at circuit board= 13.15. Then Yellow=11.47. A drop in volatage. Check brown wires to thermostat = 13.15. Can't find Relay. Wires go into the top front of the heater towards the back, but when I removed the inspection plate in the back of compartment there was only the heating element and no Relay. I believe that the unit is Locking out. A 30 second delay in turning the unit off and on does not reset it. Replaced inside switch. 13.15 voltage to switch. Replaced thermostats and circuit board. Connections clean and good ground. ???

[Old-Biscuit]

IF your model is either GC10A-4E ---no coolant lines form motor
OR the GCH10A-4E.....coolant lines from motor

The DC Relay is inside the cover that is on Back at bottom of WH tank
That is Atwood OEM.




Slight 1 volt drop thru circuit board is not an issue

There is no 'time delay' OEM.......there is a LOCK-OUT and has to be manually reset but turning On/Off Switch OFF...wait 30 then Back ON
LOCK-OUT:
*If Flame fails to light and prove it lit within 6-7 seconds of Ignition Trial
*If ECO OPENS due to Hi temp (180*F) on gas and/or electric

(on electric there is Millivolt current to/thru ECO so it is part of the 'Temp Control Logic'
on gas it has Full DC Voltage)

[viktor]

Thanks for the picture. However on my GCH10A-4E the back cover only covers the heating element. The picture you have provided appears to be the 6 gallon unit as shown in the puiblication MPD 93755. Unfortunately the publication does not show the location of the relay for the 10 gallon unit.

[Old-Biscuit]

Atwood OEM 6 gal/10 gal..uses same parts/same locations

Somebody had to remove the DC Relay and relocate it if NOT with the element
who/where......Winnebago mystery

https://pdxrvwholesale.com/products/...tune-up-kit%20

[Old-Biscuit]

Did you find the DC Relay with Yellow Wire, Green wire and 2 Black Wires?
*1 black wire from CB to Relay and then 1 black wire from Relay to Element

[viktor]

I have not looked. Parts to arrive this Thursday. Did call Dometic and received the picture showing the relay off to the side, but also, The technician’s 41 page service manual. It, however, does not show the location, but is otherwise extremely thorough regarding repair and diagnosis.

[Old-Biscuit]

Originally Posted by viktor

I have not looked. Parts to arrive this Thursday. Did call Dometic and received the picture showing the relay off to the side, but also, The technician’s 41 page service manual. It, however, does not show the location, but is otherwise extremely thorough regarding repair and diagnosis.

Pg 33 top 2 diagrams 6 gal and 10 gal