Hot water heater too hot

[johnsobc]

I was getting too much hot water in comparison to last season. I’ve changed the thermostats, and made sure the air pocket was replaced. Still heating too hot. I used to shower with only the hot water on.. now I have the cold water on full at the same time.. Could things still work to this level but still have a bad circuit board? The two lights on it arent lighting while in demand..

[mobeewan]

X

[bguy]

If you were showering with the water full hot I would suggest the WH by pass valve may have been open allowing a blend of water. If not then you heater was definitely not working properly before.

[wa8yxm]

I had to change tanks and suddenly my 120 hot water is 160.. I just mix in some cold.

There is (For the shower) a special mixer valve you can use. it is thermostatic. Alas. I no longer have links to it but google Thermostatic shower valves.

One of them looks like this one, only for a hand held shower the outlet shoud be on top. Or you can add a vacuum breaker and hook the hose to the bottom

Option Number 1

Thought I had an option 2 but no joy

[Traver8]

I would like to suggest another possibility from personal experience. My Atwood overheated on electric a couple of times once when the system was "off".

What I finally found was that the 120v relay in the back was stuck closed and continuosly providing power to the element.

Mint be something else to check.

Terry

[Old-Biscuit]

johnsobc wrote:
Just electric..

Correct......
ECO terminals are larger then T-stat terminals so BROWN wires will not FIT on ECO\Atwood only uses 140*F t-stat

When you pulled the RED wire off ECO were you just heating with electric, with propane or both?

From your description sounds like 'power track' on circuit board is shorted
NO ECO (RED WIRE removed)...NO Heating electric OR propane unless circuit board is bad

Test the board.

[johnsobc]

Just electric..

Correct......
ECO terminals are larger then T-stat terminals so BROWN wires will not FIT on ECO\Atwood only uses 140*F t-stat

When you pulled the RED wire off ECO were you just heating with electric, with propane or both?

From your description sounds like 'power track' on circuit board is shorted
NO ECO (RED WIRE removed)...NO Heating electric OR propane unless circuit board is bad

[Old-Biscuit]

Here is the test procedures for circuit board PER ATWOOD

Atwood potted circuit boards can be tested using a multi-meter.
This test must be performed with the circuit board removed, and the meter set to the ohms scale.
This will check the continuity of all tracks on the harness connection of the board.

The following steps should be used to test each track.
A. Cross leads of meter to ensure it is registering continuity.

B.TO TEST POWER TRACK:
Place negative lead of the multi-meter to ground (green wire) track of edge connection and positive lead of the multi-meter to top power (brown wire) track of edge connection.
If no continuity, board is defective.

C. TO TEST LAMP TRACK:
Place negative lead of the multi-meter to ground (green wire) track of edge connection and positive lead of the multi-meter to lamp (blue wire) track of edge connection.
If no continuity, this indicates blown lamp track.
Circuit board will still fire unit but lamp light will not come on. This is caused by a short in the blue wire between the unit and the switch.
Wiring must be corrected before the board is replaced.

D.TO TEST VALVE TRACK:
Place negative lead of the multi-meter to ground (green wire) track of edge connection and positive lead of the multi-meter to valve (red wire) track of edge connection.
If no continuity, this indicates a blown valve track.


Simple...quick tests
So before doing anything else.....test the board

[Old-Biscuit]

johnsobc wrote:
I replaced one at a time to avoid confusion, but I believe the wire posts are different sizes and wouldn’t allow for this?

dougrainer wrote:
1. Air pocket has no bearing on hot water
2. The standard tstat is either 130 or 140, depends on the year of the Atwood. EITHER tstat, you could NOT just shower on HOT only. You would be scalded. That points to a problem prior to this problem
3. Let it continue the heat cycle and see if the ECO trips and/or the pop off valve opens. No harm if it does
4. It is very easy to install a ECO in place of the tstat. That means the temp of the water could reach 180(ECO Temp trip). I would suspect you have installed the ECO instead of the correct tstat in the tstat mount. Doug

Correct......
ECO terminals are larger then T-stat terminals so BROWN wires will not FIT on ECO\Atwood only uses 140*F t-stat

When you pulled the RED wire off ECO were you just heating with electric, with propane or both?

From your description sounds like 'power track' on circuit board is shorted
NO ECO (RED WIRE removed)...NO Heating electric OR propane unless circuit board is bad

[johnsobc]

Is this in the ECO?

donn0128 wrote:
Then your upper limit switch is stuck closed.

[johnsobc]

I replaced one at a time to avoid confusion, but I believe the wire posts are different sizes and wouldn’t allow for this?

dougrainer wrote:
1. Air pocket has no bearing on hot water
2. The standard tstat is either 130 or 140, depends on the year of the Atwood. EITHER tstat, you could NOT just shower on HOT only. You would be scalded. That points to a problem prior to this problem
3. Let it continue the heat cycle and see if the ECO trips and/or the pop off valve opens. No harm if it does
4. It is very easy to install a ECO in place of the tstat. That means the temp of the water could reach 180(ECO Temp trip). I would suspect you have installed the ECO instead of the correct tstat in the tstat mount. Doug

[johnsobc]

GC6a-10E..

Swapped both the t-stat and eco sensors.

Removing ECO wire did not turn on any lights, and I could still hear the high pitched sound of the heater active. Removing t-stat wire did not turn on any lights, but did stop the high pitched sound.

No light comes on to indicate demand either?

Old-Biscuit wrote:
Atwood 6 gal...............?????


WHICH MODEL of Atwood 6 gal?

GC6a-10E uses on set of t-stat/eco for temp control
t-stat OPENS at 140*F (Closes at 110*F)
eco OPENS at 180*F (Closes at 150*F)----triggers FAULT Light and 'Locks Out' ALL heating

Atwood XT Model GE6EXT uses one set of t-stat/eco PLUS a mixing vlave
t-stat OPENS at 160*F (Closes 130*F)
eco OPENS at 180*F (Closes at 150*F)----triggers FAULT Light and 'Locks Out' ALL heating
MIXING Valve set for 130*F output......HOT HOT water is mixed with cold to maintain steady output



Standard model.....BOTH T-stat & ECO would have to FAIL CLOSED
XT Model....BOTH T-stat & ECO would have to FAIL CLOSED OR the Mixing Valve Cold INLET is not mixing with the HOT HOT out




To Test 'heating cycle' (either model) with water heater ON and heating ----remove a RED wire from ECO terminal....all heating should stop and fault light should come on

[dougrainer]

1. Air pocket has no bearing on hot water
2. The standard tstat is either 130 or 140, depends on the year of the Atwood. EITHER tstat, you could NOT just shower on HOT only. You would be scalded. That points to a problem prior to this problem
3. Let it continue the heat cycle and see if the ECO trips and/or the pop off valve opens. No harm if it does
4. It is very easy to install a ECO in place of the tstat. That means the temp of the water could reach 180(ECO Temp trip). I would suspect you have installed the ECO instead of the correct tstat in the tstat mount. Doug

[Old-Biscuit]

Atwood 6 gal...............?????


WHICH MODEL of Atwood 6 gal?

GC6a-10E uses on set of t-stat/eco for temp control
t-stat OPENS at 140*F (Closes at 110*F)
eco OPENS at 180*F (Closes at 150*F)----triggers FAULT Light and 'Locks Out' ALL heating

Atwood XT Model GE6EXT uses one set of t-stat/eco PLUS a mixing vlave
t-stat OPENS at 160*F (Closes 130*F)
eco OPENS at 180*F (Closes at 150*F)----triggers FAULT Light and 'Locks Out' ALL heating
MIXING Valve set for 130*F output......HOT HOT water is mixed with cold to maintain steady output



Standard model.....BOTH T-stat & ECO would have to FAIL CLOSED
XT Model....BOTH T-stat & ECO would have to FAIL CLOSED OR the Mixing Valve Cold INLET is not mixing with the HOT HOT out




To Test 'heating cycle' (either model) with water heater ON and heating ----remove a RED wire from ECO terminal....all heating should stop and fault light should come on

[donn0128]

Then your upper limit switch is stuck closed.