Help with suburban sw10de electric WH

[tshryock]

Problem: Gas side of WH works fine; electric does not work.

After reading as many previous posts on this topic as I could find, I did a methodical test of each piece of the water heater (a suburban sw10de) using a multimeter. Here's what I found:
Switch -- tests out ok
thermostat -- tests ok
element -- I have 120v on BOTH wires (one lead on wire lead and the other to ground).

Another post said this means it's a problem with the return wire and I needed to trace it, but that's all the instructions provided. The white wire from the element disappears behind the cover.

When I go inside the camper and look at the other side of the heater, I don't see any white wire returning. On the left side (as viewed from inside the camper - the end where all the water connections are) there are a lot of colored wires, and this appears to be the DC igniter system for the gas side. On the right side, there is a heavy cable that runs near the heater and exits directly through the cover, about where the switch is, so I'm assuming that's the power going out to the unit.

On the upper part on the right side is a metal junction box. Inside of that are a black and white wire that go through the cover (to the outside) and another pair (black/white) that enter a thinner protective cable and disappear down a hole in the floor under the sink.
I checked the connections and they appeared to be good, but redid them anyway.

And now I'm at an impasse. What else should I be checking? Where does the wire that goes down through the floor go? Is there other wiring I should be checking? Where does the white wire from the heating element go - is it the one entering the junction box?

I'm not really sure where to go from here...all help appreciated!

Thanks

[cavie]

Originally Posted by tshryock

Problem: Gas side of WH works fine; electric does not work.

After reading as many previous posts on this topic as I could find, I did a methodical test of each piece of the water heater (a suburban sw10de) using a multimeter. Here's what I found:
Switch -- tests out ok
thermostat -- tests ok
element -- I have 120v on BOTH wires (one lead on wire lead and the other to ground).

Another post said this means it's a problem with the return wire and I needed to trace it, but that's all the instructions provided. The white wire from the element disappears behind the cover.

When I go inside the camper and look at the other side of the heater, I don't see any white wire returning. On the left side (as viewed from inside the camper - the end where all the water connections are) there are a lot of colored wires, and this appears to be the DC igniter system for the gas side. On the right side, there is a heavy cable that runs near the heater and exits directly through the cover, about where the switch is, so I'm assuming that's the power going out to the unit.

On the upper part on the right side is a metal junction box. Inside of that are a black and white wire that go through the cover (to the outside) and another pair (black/white) that enter a thinner protective cable and disappear down a hole in the floor under the sink.
I checked the connections and they appeared to be good, but redid them anyway.

And now I'm at an impasse. What else should I be checking? Where does the wire that goes down through the floor go? Is there other wiring I should be checking? Where does the white wire from the heating element go - is it the one entering the junction box?

I'm not really sure where to go from here...all help appreciated!

Thanks

Did you look for a switch inside? Mine also has a 120-volt switch under the kitchen sink.

When checking the element, remove the neutral (white) wire Then check each screw to ground. or each screw to the loos wire.

[bob213]

Remove one wire with power off and use the ohm setting to check the continuity of the element. infinite reading is bad.

[tshryock]

With power off I tested both screws of element using lowest ohm setting on multimeter. One lead on screw and one on frame gave a 1 on the meter for both sides. Both leads on screws gave a 9.8.
Does this tell me anything? Other tests I should do?

[rockfordroo]

Originally Posted by tshryock

With power off I tested both screws of element using lowest ohm setting on multimeter. One lead on screw and one on frame gave a 1 on the meter for both sides. Both leads on screws gave a 9.8.
Does this tell me anything? Other tests I should do?

It sounds like you are setting the meter for ohms, but using like you're measuring for voltage. You have to remove at least one of the leads on the element in order to check it's continuity with an ohm meter. Then put one lead on each of the two screws on the element. That way you are reading through the element.

(When you read ohms, the meter actually sends current from its battery through the device you're measuring and determines the resistance from the voltage drop through the device. You lift one of the wires from the device so that the current can't go anywhere else but back to the meter. If you don't lift one wire, you are not only reading through the element, but you're reading the other way through all the other wiring and back to the element.)

[tshryock]

Yes I removed one wire to do the test to get those results. I also hooked wires back up and I have 120v on both wires when one lead is on screw and one on ground. Shouldn't I have 0v on white wire?

[bob213]

Try taking both wires off and test at both screws with ohm setting and see what reading you get.

[bubbles]

9.8 ohms would be about right for the element.

[rockfordroo]

Originally Posted by tshryock

Yes I removed one wire to do the test to get those results. I also hooked wires back up and I have 120v on both wires when one lead is on screw and one on ground. Shouldn't I have 0v on white wire?

If you have 120 volts on each side, that implies there's no current flow through the element, so there's no voltage drop. So I agree that you have somehow lost the ground. You need to trace that white wire.

[tshryock]

OK - back at this over the weekend. Thanks for the help so far. I'm trying to trace the white wire back through the rig and here are my observations from before:

When I go inside the camper and look at the other side of the heater, I don't see any white wire returning. On the left side (as viewed from inside the camper - the end where all the water connections are) there are a lot of colored wires, and this appears to be the DC igniter system for the gas side. On the right side, there is a heavy cable that runs near the heater and exits directly through the cover, about where the switch is, so I'm assuming that's the power going out to the unit.

On the upper part on the right side is a metal junction box. Inside of that are a black and white wire that go through the cover (to the outside) and another pair (black/white) that enter a thinner protective cable and disappear down a hole in the floor under the sink.
I checked the connections and they appeared to be good, but redid them anyway.

Question: Is my assumption that the junction box is where the power is returning correct, or is that the power on the way to the switch and the other cable would be the return?
And if there's some easy way to trace a wire, please let me know!

[rockfordroo]

There should be an 120VAC outlet near your water heater; the water heater will be plugged into it.

I replaced the RV "speed outlet" with an electrical box and house style 120V outlet so I could switch it on/off with an inside switch with pilot light.

Here's what a "speed outlet" looks like:


I installed the new electrical box right where the original "speed outlet" was located. See the pic below. The water heaters white insulation is the white you see in the upper left corner of the pic, above the 2x4 the box is attached to.



The wiring is very simple. The white wire should go back the plug, along with the black wire and ground wire. See the left side of the wiring diagram below (this diagram should be in your owners manual, too). The three wires on the far left should go right to the 120VAC plug.



Once you've figured out your problem, if you want to install an inside switch, I've attached the wiring diagram as a PDF below. You leave the outside switch ON and turn the water heater on/off with the inside switch. Here's a pic of my installed switch:

[rockfordroo]

BTW: Here's a Service and Training manual for you.

[tshryock]

Your setup must be different – I don’t have any electrical outlets near the water heater. The electrical cables from the heater both disappear through the floor.

[rockfordroo]

Originally Posted by tshryock

Your setup must be different – I don’t have any electrical outlets near the water heater. The electrical cables from the heater both disappear through the floor.

Hmm. Interesting. Be sure to let us know when you figure it out.