Problem with Atwood water heater

[dmcrick]

My water heater is electric and gas. When I turn the switch on it does not work on electricity. It does operate and ignite on gas. However it runs until the pressure relief valve spews water. I have changed out the thermostat and ECO. What could the issue be? Does it need a new circuit board?

[js6343js6343]

Did you find a resolution to your electric water heater problem? I am having a similar issue. Gas works fine. No electric. I have replaced the thermostat and element with no success. I am getting intermittant 120V to the element but not long enough to bring the water to hot temperature.

[marcsbigfoot20b]

Mine didn't work on electric one day either.
Bumpy road to Mexico loosened one AC wire to the element and it simply fell off. Thankfully the inside of the tiny electrical box is insulated.

[dmcrick]

Is it possible I put in the wrong thermostat for my atwood model GC6AA-9E. The part I installed was part# 91447. My RV is a year 2000 model. Here is the link for it. http://www.amazon.com/dp/B0016ZBP1Q/ref=pe_385040_30332190_TE_M3T1_ST1_dp_i1

[JJBIRISH]

The T&P valve is functioning properly when it relieves pressure caused by thermal expansion, but frequent relief can build up natural mineral deposits on the valve seat, rendering the valve inoperative… If there is no discharge from the valve, there is no need to replace the valve… the wax isn’t a factor…

A good indication of thermal expansion is when the T&P valve releases about one cup of water for each 10 gallons of heater capacity with each heating cycle…

Losing the air pocket can cause the same problem… there needs to be enough air in the tank to absorb the thermal expansion, because the RV water system doesn’t have a water expansion tank anywhere in the system and water doesn’t compress… air does…

reestablish your air pocket first and see how it works first… or your need to measure the water temp and see if it is really overheating… the RV water heater is designed to provide super-hot water (above recommended temps for a home water heater)…

[DiskDoctr]

You may want to check your electrical connections. Your new thermostat should have two limit switches, one for the thermostat and one for the high limit.

It sounds like neither is working in a brand new unit? You ordered the set of two, right? What is the part number or a pic/link?

Are you sure you reconnected the wires in the correct place?

Connecting the thermostat wire to the high limit would make it far too hot, but should trip before the tpo, unless it is crapped out, too (maybe Scott was correct about the TPO being bad, in spite of the wax miswording 😉 )

[dmcrick]

The water heater model is GC6AA-9E. The PRV is not spewing but started pouring water out. The water was extremely hot and the water heater had ran for about 40 minutes without shutting off. I did replace the thermostat and ECO. I am quite sure they are both tight against the tank. There are two problems. First it does not run on electricity at all. Second on gas it does not shut off and starts running water out of the PRV. If it is not the thermostat is it possible it is the circuit board?

[dmcrick]

The model is GC6AA-9E. I am sure the new thermostat is properly seated against the tank. I did clean the spot off on the tank before installing. It runs on gas for about 40 minutes and does not shut off. The pressure relief valve is not weeping water it is spewing water. I shut off the water heater at that point and run the hot water and it is extremely hot. It will not run at all on electricity. The trailer is a 2000 Nomad. I have opened the pressure relief valve all the way and closed it. There are two problems. It does not run on electricity and will not shut off automatically on gas.

[DiskDoctr]

ScottG wrote:
Once a TPO spews hot water because of being over temp, it's shot because there's wax in it that melts. You have to replace it after fixing the root problem.

Your statement certainly seems to say that because the wax melts the first time the TPO is ruined.

I've had them wear out, but most often due to crud in the TPO, interfering with operation, mostly resulting in a leaking valve.

As politely as I can say it, I am quite certain TPOs do NOT fail, requiring replacement the first time they are tripped because of a melted wax component.

I didn't realize there was wax sealed inside the unit, however. That was an interesting piece of info.

[ScottG]

The wax portion hardens and doesn't perform normally time after time - that has been my experience.
So we can just agree to disagree.

[Old-Biscuit]

ScottG wrote:

Old-Biscuit wrote:

ScottG wrote:
Once a TPO spews hot water because of being over temp, it's shot because there's wax in it that melts. You have to replace it after fixing the root problem.

Where do you get this idea of 'wax' melting? It's not a fire sprinkler.

A T&P valve operates on 2 principles

1) High pressure (150#) overcomes spring pressure opening valve disc off seat and discharges water until pressure drops (125#). Drop in pressure is due to pressure being relieved thru T&P and the influx of cold water

2) High temperature (210*F). The probe is a thermostatic element that expands and lifts the valve disc off the seat relieving the overheated water which allows the influx of cold water. When the temperature cools below 210*F the thermostatic element will contract allowing the spring to close the valve disc against the seat.
And the T&P is ready to function again and again and again on high temp/high pressure situations.

You can (and should yearly) test the valve function by manually opening valve via lever and allow it to snap shut.

There is no wax that melts.

You are wrong on #2. There is wax in the section for temperature control (That's what expands) and it can and does fail completely. It is not designed to be triggered repeatedly. Link


Can you not discuss differing opinions without employing rudeness? Can you not offer another opinion and conduct yourself as a gentleman?

I misspoke.....
There is a wax fill inside the probe.

The wax doesn't melt and become unusable..it expands due to heat and then contracts when it cools. The wax is the means of the thermostatic element function. Can be used over and over and over.
T&Ps end up having to be replaced when spring tension weakens and/or valve disc/seat no longer seal.......not because they have operated.

[ScottG]

Old-Biscuit wrote:

ScottG wrote:
Once a TPO spews hot water because of being over temp, it's shot because there's wax in it that melts. You have to replace it after fixing the root problem.

Where do you get this idea of 'wax' melting? It's not a fire sprinkler.

A T&P valve operates on 2 principles

1) High pressure (150#) overcomes spring pressure opening valve disc off seat and discharges water until pressure drops (125#). Drop in pressure is due to pressure being relieved thru T&P and the influx of cold water

2) High temperature (210*F). The probe is a thermostatic element that expands and lifts the valve disc off the seat relieving the overheated water which allows the influx of cold water. When the temperature cools below 210*F the thermostatic element will contract allowing the spring to close the valve disc against the seat.
And the T&P is ready to function again and again and again on high temp/high pressure situations.

You can (and should yearly) test the valve function by manually opening valve via lever and allow it to snap shut.

There is no wax that melts.

You are wrong on #2. There is wax in the section for temperature control (That's what expands) and it can and does fail completely. It is not designed to be triggered repeatedly. Link


Can you not discuss differing opinions without employing rudeness? Can you not offer another opinion and conduct yourself as a gentleman?

[Old-Biscuit]

ScottG wrote:
Once a TPO spews hot water because of being over temp, it's shot because there's wax in it that melts. You have to replace it after fixing the root problem.

Where do you get this idea of 'wax' melting? It's not a fire sprinkler.

A T&P valve operates on 2 principles

1) High pressure (150#) overcomes spring pressure opening valve disc off seat and discharges water until pressure drops (125#). Drop in pressure is due to pressure being relieved thru T&P and the influx of cold water

2) High temperature (210*F). The probe is a thermostatic element that expands and lifts the valve disc off the seat relieving the overheated water which allows the influx of cold water. When the temperature cools below 210*F the thermostatic element will contract allowing the spring to close the valve disc against the seat.
And the T&P is ready to function again and again and again on high temp/high pressure situations.

You can (and should yearly) test the valve function by manually opening valve via lever and allow it to snap shut.

There is no wax that melts.

[ScottG]

Once a TPO spews hot water because of being over temp, it's shot because there's wax in it that melts. You have to replace it after fixing the root problem.

[westend]

Take it to Camping World.