Hot water Heater not working on Electric

[jnjeter]

When in camp if electric pwr is availbe, I switch our Atwood 6gal Gas/Electric to electric. Last time out, I switched to Gas for travel. That evening I switched back to Electric but it would not engage. Breaker not thrown . No problem with Gas operaton. This heater has a drain plug only, no anode.
Suggestions as to troubleshooting ?

[hotpepperkid]

Dick_B wrote:
We used to do the same thing; rely on electric for virtually all our water heating UNTIL I spent the weekend troubleshooting why our electric did not work and a couple of weeks to fix it. Turned out the switch by the heater melted along with at least one of the power wires to the switch all of which I replaced.
Now we heat on propane and save the electric for emergencies.

I burned up the relay once

[jnjeter]

Thx to all for suggestions.....looks like I have several trouble-shooting methods to hopefully resolve.

[Hank_MI]

Old-Biscuit wrote:

Hank MI wrote:

Old-Biscuit wrote:
Your Atwood model uses one set of t-stat/eco, one control board and same DC Voltage for heating with electric and/or propane.

How do you know what model he has? Are you basing it on year of his rig? I know that you know a lot about these units so just curious.

Our 10 gallon Atwood stopped working on electric. Only had to reset the ECO for electric. It's been working fine on electric since then, one year ago.

YES...OP has a 2005 RV

Atwood changed design/controls in 2004
2003 and previous models used 'separate' controls for electric and propane each with their own set of t-stats
2004 and newer....all combined into one control design

Thanks.

[dons2346]

Dick_B wrote:
We used to do the same thing; rely on electric for virtually all our water heating UNTIL I spent the weekend troubleshooting why our electric did not work and a couple of weeks to fix it. Turned out the switch by the heater melted along with at least one of the power wires to the switch all of which I replaced.
Now we heat on propane and save the electric for emergencies.

Same here. Had the cheap on/off switch fall apart. I took the switch out of the circuit as it really isn't needed because the heater is on its own circuit breaker. If you want to turn the electric off, flip the breaker I still heat with electric unless off grid.

[Old-Biscuit]

Hank MI wrote:

Old-Biscuit wrote:
Your Atwood model uses one set of t-stat/eco, one control board and same DC Voltage for heating with electric and/or propane.

How do you know what model he has? Are you basing it on year of his rig? I know that you know a lot about these units so just curious.

Our 10 gallon Atwood stopped working on electric. Only had to reset the ECO for electric. It's been working fine on electric since then, one year ago.

YES...OP has a 2005 RV

Atwood changed design/controls in 2004
2003 and previous models used 'separate' controls for electric and propane each with their own set of t-stats
2004 and newer....all combined into one control design

[Hank_MI]

Old-Biscuit wrote:
Your Atwood model uses one set of t-stat/eco, one control board and same DC Voltage for heating with electric and/or propane.

How do you know what model he has? Are you basing it on year of his rig? I know that you know a lot about these units so just curious.

Our 10 gallon Atwood stopped working on electric. Only had to reset the ECO for electric. It's been working fine on electric since then, one year ago.

[LittleBill]

Dick_B wrote:
We used to do the same thing; rely on electric for virtually all our water heating UNTIL I spent the weekend troubleshooting why our electric did not work and a couple of weeks to fix it. Turned out the switch by the heater melted along with at least one of the power wires to the switch all of which I replaced.
Now we heat on propane and save the electric for emergencies.

Your issue was prolly a bad connection, which caused a heat build up.

i would not be afraid to use it, if your corrected the wiring.

[Dick_B]

We used to do the same thing; rely on electric for virtually all our water heating UNTIL I spent the weekend troubleshooting why our electric did not work and a couple of weeks to fix it. Turned out the switch by the heater melted along with at least one of the power wires to the switch all of which I replaced.
Now we heat on propane and save the electric for emergencies.

[j-d]

wa8yxm wrote:
I would not use Scotch lock type (Like above) for anything that NEEDS to be connected, I've had to re-do far too many connections done that way.

120 vac is delivered via Romex to a box on the back (inside) of the water heater.. No need to remove unit from RV to check

AND I FULLY AGREE ABOUT NOT USING THESE! SEE CLARIFYING EDITS IN ALL CAPS ABOVE

Our Suburban has the connection box on what I'll call the "Front" (meaning outside wall end) of the water heater, making it all but impossible to access from inside a cabinet. That's probably why Jayco ran that pigtail of Romex to the punch-down box I mentioned.

[wa8yxm]

I would not use Scotch lock type (Like above) for anyting that NEEDS to be connected, I've had to re-do far too many connections done that way.

120 vac is delivered via Romex to a box on the back (inside) of the water heater.. No need to remove unit from RV to check

Inside this box is a 12 volt powered relay

Check for 120 volt, and 12 volt with the tank full of COLD water.

IF one or the other is not there, get back with us

Just above that box is the heat element. Disconnect one wire, measure the screw to screw resistance and get back with us on that as well.

[j-d]

Many Mobile Home and RV connections use "displacement" aka "piercing" or "punch down" connectors. Both Junctions and Receptacles, probably also Switches, can be wired using these. Clearest example is this Scotch Lock type where two wires lie parallel in the housing and then the little metal piece is squeezed down, cutting through the insulation and wedging onto the conductors. EDIT: THIS CONNECTOR IS PICTURED AS AN EXAMPLE OF WHAT NOT TO USE BECAUSE THEY FAIL!!!
Our RV had ONE OF THOSE junction boxes on the floor inside a cabinet connecting wiring from the breaker panel to a short pigtail coming back from the water heater. The Neutral (White Wire) side had arced and became an Open. I'd heard of this before on water heater circuits. I took the connecting metal pieces out, gutted the plastic to form a Box, stripped and mechanically twisted the wires together. I then screwed Wire Nuts over the connections, taped them against unscrewing, and "punched" the cover back on. Fine since.
Note: the splice where a flexible shore tie cable splices to the hard wire used within an RV often fails and has to be re-done. Running resistive electric heaters seems to contribute to that.

[Old-Biscuit]

Your Atwood model uses one set of t-stat/eco, one control board and same DC Voltage for heating with electric and/or propane.

The 120V AC to electric element is triggered via a DC Relay

White wire to circuit board is the DC from electric on/off switch
Then DC must go to/thru t-stat and back to circuit board
Then a very small millivolt goes to/thru ECO and gas valve so ECO is part of control circuit

THEN DC goes to relay to trigger AC to element
Any loss of DC prior to relay will not allow electric element to function

AC at the DC relay and element can be issue also....there are on backside of tank under the black protective cover......PITA to access
SO check DC circuit first

Here is the wiring scheme

[Artum_Snowbird]

First step would be to take the electrical cover off where the wires connect to the water heater and see if there is power there. Ensure you have positive power on the black lead when measuring it to the ground lead, and that you have power from the black to the neutral.

Next is shut off the breaker, remove the wires from the heater connection, and measure the ohms resistance across the heater element. It should be well less than one ohm, more like 1/10 of an ohm. If it is more than that, it is broken inside.

I haven't looked at many... not sure if they have a plug in connection like the fridge does. If that is the case, try with a good extension cord before anything, then do the tests.