Brand new G6A-8E Water Heater short cycling

[DallanC]

Greetings,

I have a brand new toy hauler that has had hot water heater problems since the first trip out. I returned it for warranty work and the repair attempt took 5 weeks, and the dealer made it worse! We intend to return the trailer to the dealer at the end of the camping season, but I refuse to pay many 10's of thousands of dollars only to have my trailer sit at the dealer all summer. I'm more than willing to fix minor issues than wait on the dealer.

So quick history: Brand new 2020 Eclipse Attitude 19FBG trailer with a G6A-8E Water heater. The initial problem was the hot water heater started up just fine, but would not cycle back on after the hot water was used. The dealer took 5 weeks, "adjusted the gas" and said it was fine. I took the trailer home, found the heater turned on just fine but now would never shut off...! And the gas was completely out of wack sounding like a jet engine.

Some quick googling showed me similar issues solved with new thermostats, so I ordered some new ones (remember, this is a brand new unit!) and swapped them out and re-adjusted the gas. The heater started up just fine, ran great then shut off when the water temperature was 138F at the faucet. We ran the hot water out and the heater restarted and heated up the water just fine.

I thought we had it solved!

So, this past weekend we went camping again (2nd trip out in the new trailer), and noticed that after the hot water heater properly heated up the tank and shut off, it would cycle back on after a few minutes, run for about 1 minute, shut off... repeat, indefinitely until I turned off the power.

Could I have gotten a bad set of thermostats or is this more likely now pointing to a board issue? I thought I was pretty careful to make sure the thermostats were in full contact with the tank, but I will double check that again when I get home.

I can deal with this quirk for the remaining summer camping trips, at least we have hot water for showers. If it sounds like a board the dealer can deal with that come fall... although I am extremely unhappy with their service currently.

IDK what else to try. The unit is new, looks great with no corrosion on any wiring or connectors. Any thoughts?

Thanks, in advance!


-DallanC

[Old-Biscuit]

Couple of things you can check....

*Green wire connection........clean/tight --- need a good solid ground
*When t-stat OPENS (140*F) should still have 12VDC on Brown Wire to the T-stat
When t-stat CLOSES (110*F) should have 12VDC on Brown Wire at connector on circuit board
IF T-stat is causing the intermittent firing cycle then the 12VDC would fluctuate at the Brown Wire spade connector from t-stat to circuit board
*With 12VDC thru Brown Wire to circuit board then 12VDC is sent to/thru ECO to Gas Valve
IF circuit board is causing intermittent firing then 12VDC would fluctuate at Red Wire connections at ECO


You can also run couple tests on circuit board for continuity.....Unplug connector and remove circuit board
Use Voltmeter set to Ohms Scale

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


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


I suspect ground issue or circuit board fault

[DallanC]

So I carefully removed the T-Stat last night. It seemed like it had been seated flush with the tank, but still I rubbed the face of the T-stat with a scotch bright pad. I then did the same with the tank surface. I very very carefully reinstalled the T-stat (took a couple tries, twisting it in would sometimes misalign it).

All reinstalled I fired it up, it heated up quickly, when it hit max temp it shut off... I then started my timer and waited... and waited... the short cycling didn't happen!

So apparently the T-stat wasn't completely flush with the tank? If it wasn't, it wasn't off by more than a few thousandth's. So I'm happy, and I do appreciate the comments and suggestions.

-DallanC