Hot water heater issues...

[Advmoto18]

Right out of the blue, my never had an issue water heater is now acting up. Not the same as XJINT's post.

Turn water heater switch on, light stays on, no gas flow or ignition. Intermittently, it would light off but shut down on its own after ~5 minutes. Called Atwood. They were very helpful with suggestions.

Today, it never lighted. So I created a jumper to bypass the ECO (2 red wires). Water heater lighted off several times without issue. Stopped by an RV Center and purchased a new ECO for $13. Installed at tonight's dispersed camp site. Water heater lighted off and worked fine. Turned it off. About 10 minutes later wife turned it but no light off. Installed jumper...still didn't work. After about another 20 minutes, water heater lighted off and ran normally .

I beginning to think I'm now experiencing water over temperature lockout. What would all of a sudden begin causing this issue?

Thanks for any suggestions.

Bill

 

[Old Crow]

Bill- You might read through the following manuals for ideas....

Beamalarm's Atwood Water Heater Troubleshooting Manual

Atwood L.P. Gas Water Heater Manual for 4, 6, and 10 Gallon models

I don't have any practical experience with these but the intermittent nature of the problem would have me looking closely at connections (including the thermal cutoff), making sure the ECO and thermostat contact with the tank are good, looking for a cracked insulator on the spark electrode, looking for a crack in the circuit board, testing the circuit board. The Beamalarm manual makes the point that the circuit boards are pretty reliable so that's what you do after eliminating everything else. If you get to that point, call local RV shops to ask if they have the tester and adapter for water heaters (like this Dinosaur one) (I mention that because my local shop tested my furnace board for free)

And, of course, keep talking to Atwood tech support as you learn more.

Also--- a bit of visual assistance....

More detail on wiring, testing of thermal cutoff and gas-valve coils, etc....

 

[Advmoto18]

Thanks!
When I put the new Eco in, I ensured good contact with the tank. New springs are pretty stout.

If thermal connector was blown, I wouldn't be getting intermittent operation. Also, the jumper wouldn't allow the heater to operate as well.

I dropped by an RV center yesterday and they had a 12 day wait just to scan the board!!!! The migration north has begun!

Thanks for the vids!

I will call Atwood again Monday. But I'm fairly certain I'm experiencing water overheat lock out as described on the access door of the camper. Not sure what would cause that after installing a new ECO.

Bill

 

[Old Crow]

Agree on the thermal-cutoff. I was just thinking it also has connectors which could be dirty or intermittent. As you say, the fuse itself should be an "it-works-or-it-doesn't" thing.

If you are indeed having an overheat lockout, I'd think that indicates the thermostat sensor is bad. It normally tops out at 140 degrees to halt further heating. But if it fails, the Emergency Cut Off opens at 180 degrees, cutting power to the gas valve. That shouldn't happen in normal operations. And if it does, I'd think the water would be noticeably hotter than normal. I had the impression from your original post that the heater is shutting down prematurely rather than overheating (and perhaps it's a sometimes-this-sometimes-that situation).

That failure to start the burner would I think be related to the flame sensor (at the igniter electrode) failing to detect flame in 6-8 seconds of attempted firing and the circuit board putting the system into lockout. We don't know whether the culprit is lack of constant electrical connection or lack of gas. But you might look at about the ten-minute mark in that second video for some tests and observations you can do to help narrow down what it might be.

 

[Advmoto18]

Thx Old Crow! Sorry for the delayed reply...been off the grid.


Water Heater is still acting up. Doesn't light off when switch turned on, light stays on. After a random number of a few minutes, it lights off and runs for about 4-8 minutes then shuts down.

New ECO and T-stat installed last week.

Ordered a new board through Amazon. Going to Yuma tomorrow to pick it up at a friend's. If not board only thing it could be a gas selinoid valve.

If thermal cutoff were bad, heater wouldn't run at all according to Atwood.

ECO not the fault since heater doesn't work with a jumper. Could be a bad new T-stat. But doubtful.

More in the next day or two.

Thx!

Bill

 

[Old Crow]

I'm wondering about the igniter (the spark and sense electrode). If the sense portion of it is flaky, the board would interpret that as loss of flame and would shut down the gas valve.

I don't know what the return policy is on the board but some suppliers won't take boards back if they've been opened or installed. I believe I'd pick up an igniter along the way and replace that and try again before opening the board package. Also- I'd make another run through the Beamalarm troubleshooting sequence (see #11).

PS- I'm not sure that's your igniter I linked to.

 

[Advmoto18]

Great idea about igniter.

But if ther heater lights off OK, igniter shuts down unless loss of flame is sensed.

Sometimes, After my heater runs for about 5 minutes, the flame extinguishes. Yet The igniter continues to click about 4 times then stops. Doesn't do this every time.

The very inconsistent operation has led to Atwood customer service and others perplexed.

Boards or tracks on the board usually fail completely. However if a diode or two is failing that could lead to inconsistent operation.

I've replaced problematic diodes on appliance boards with success. $2 for a handful of diodes at Radio Shak is a good deal. However the Atwood board is potted so it must be completely replaced.

 

[Advmoto18]

Issue turned out to be the board.

I have a 2015 Hawk and the Atwood water heater had a P/N 90098 circuit board installed.

Atwood now offers P/N 93865 circuit board. While the boards share the same form factor, there are several notable design differences between the boards as well as the amount of potting material on the board. The new board has several diodes and chips unpotted. Perhaps the potting on the older board was causing an over-heating issue within the diodes/chips. Who knows...

All good now.