Water Heater Not Working on Electric

[Bob Landry]

I won't have access to a meter or a manual until I get home tomorrow, so this is just a quest for information. My water heater(Suburban SW6DEL) stopped working on 115V, but works fine on gas. Just wondering how the 115V is switched to the heating element. The wall switch has to be a 12V switch because all of the switches by it are for lights(12V), so that leaves me to think that switch is operating some kind of control board with a triac or relay that switches 115 to the heating element. Any hints on where to start looking? Reset switches? I'm sure the schematic will tell me a lot but I'm sitting here in the campground really bored.. LOL

[PARAPTOR]

Looking at the schematic for my 12 gallon suburban. For the electric portion it shows a simple series circuit 115 VAC to a rocker switch to the Hi Limit/thermostat to the 1440 watt heating element then back.

Only 12V circuitry is on the gas side where the control board controls spark, gas valve, and monitors limits

I would assume the 6 gallon tank would be the same

[JRTJH]

You can download (or view online) the manual here: http://bryantrv.com/docs2/docs/operating/swinstall.pdf

If the electric heating element is not functioning, it's either burned out, a wire connection has come loose or the "high temp switch" has opened. The "reset button" under the black rubber cap opens at 180F and will not reset until the temperature in the tank is below 100F. If you've been operating the water heater on propane, you've probably never been below the 100F internal temperature, so the high temp switch will never reset to allow the electric element to function. You might want to turn off the propane, run water until the faucets run cold, then try to reset the black button.

[Bob Landry]

When we camp, we run the water heater only on electric, so propane was shut off. I'm home now si I'll look at the schematic. I would not have suspected that 115V would go through that wall rocker switch since I thonk all of the other switches are 12V(I think) I'll know more once I look at the manual. If I had to make a guess, it would have been that the wall rocker switch put 12V to a control board or relay to send 115 to the heater. By the way, the wall switch for the heater does illuminate.

[therink]

Bob, I believe you are correct about the rocker switch on the panel. All circuits on the main control panel are 12 volt. I agree that the switch for the water heater element sends signal to a relay on the board that turns on the 120v heating element.
The elements do go bad. I believe you can test the element using an ohm meter. I did it once on mine but forgot how I did it.

[Bob Landry]

The schematic shows a relay with a single set of contacts, so that makes me think that it is somewhere on the heater, I just have to find it, and I may not even need to, I just need to see if I have 115 to the heating element. I have to find that since the whole unit is incased in a styrofoam shell. I'll just have to be careful how I cut it away from the heater so I can tape it back together.

There is a black box that says RESET. Is that where the thermostat and reset switch is located?

[PARAPTOR]

Bob; Just looked at my manual again for my Suburban 12 gallon HWT as well as the manual for the 6 gallon model which John made reference to. Neither of these schematics show a relay. Neither schematic show a 12v circuit for a relay in the 12v wiring diagram, ie a rocker switch and a relay coil. Again, only 12V circuit shown is for the Gas portion of the tank.

On the 120VAC portion of the schematic no relay contacts are shown. There is a symbol that could possibly be interpreted as a relay however on these schematics are labeled as "HI Limit/T-STAT" which I think are the HI LIMIT and thermostat contacts.

Since I have a Suburban HWT, can you send me a link to what you are looking at. THX

[Bob Landry]

The manual John linked to is for a different model heater. Mine is the SW6DEL so there must be some subtle differences in the electrical portion. Mine does show a relay in the 120V diagram(fig.2 in my manual) where yours may show just a switch. The exploded diagram and parts list also shows a relay, but only shows the single set of contacts that go to the thermostat, not 12V that would control it. All of that should be in the electrical box which I hope I can access through the cabinetry without having to disconnect the gas and water lines and pull the heater. If I do I do, it's just a PITA. If it's not a bad heating element and I do have to pull it, I'm going to replace everything 120V and be done with it.

[JRTJH]

First of all, I'd ask you to make sure you have a Suburban water heater. Keystone has used Atwood and Suburban water heaters. The both have the same features (DSI propane and electric heating capability, foam tank insulation, reset buttons and electric switch on the face of the heater) but they differ significantly in how they are wired and how they function. The following is applicable to Suburban water heaters, not to Atwood !!!

If the document you're referencing is the one in the link I supplied, (Suburban SWE series water heaters) there is no relay shown in the 120VAC circuit. Shown on page 6 (figure 9) is the entire 120VAC wiring circuit. There is a "front mounted" switch (usually found under the propane supply line on the front of the tank) and a "return/ground" that are wired to the connections. These are normally enclosed in a junction box behind the heater. Any "user supplied" switches inside the coach and any wiring "to the heater" that were installed by Keystone could easily differ from model to model and even from coach to coach of the same model. That part is not Suburban so it wouldn't be included in the Suburban manual. As for whether Keystone installed an electric switch (120 VAC or 12 VDC) isn't covered in the Suburban manual. There is no relay supplied by or installed by Suburban on the heater. If Keystone provided a 12 volt interior switch and relay, they are not located on the heater. My "hunch" would be that if Keystone used any wall mounted switch, it would be a 120 VAC switch, not a 12 VDC switch and relay, so your wall switch is probably a "high voltage switch" connected to 120VAC.

As for "Suburban wiring" within the heater, the wire goes to the front power (off/on) switch, directly to the "high temp/T-Stat" and then to the heating element and to the return. There is no relay, no light anywhere in the Suburban wiring diagram. If the "single set of contacts" you're referring to are the "dots inside the circle", that is the heating element connection points that are located on the heating element. No relay is shown on the 120 VAC wiring diagram (figure 9).

There is a "service manual" available here: http://hometips.me/Mar/Suburban_Wate...ice_Manual.pdf It has expanded information complete with troubleshooting block diagram for the entire Suburban water heater series.

As for your question about the reset button, yes the two black rubber discs on the front of the heater cover the thermostat and the reset button. When you push on them, you'll feel a button under one and "nothing" under the other. That's because the thermostat doesn't have a reset button. Push both black discs (when the water temperature is below 100F) and the reset should latch to provide continuity at the "high temp cutoff switch" and allow voltage to flow to the electric heating element.

The electric heating element is located on the lower center of the face of the water heater behind a black plastic cup. There is no need to cut any of the foam insulation to access any part of the heater for replacement.

ADDED: While I was posting the above information, I guess you were posting your response. I did find the SW6DEL manual and you're right, there is a relay in that model heater that controls a 12 VDC switch and relay to turn on the 120VAC heating element. Your wall switch includes 2 switches and one light to control the propane and electric heating functions and a light to show that one or the other (or both) are in operation. The light should be on in either propane or electric operation and both switches are 12 VDC.

I would suggest that before you start tearing into the back of the water heater, you check continuity of the electric element. Disconnect either lead from the front of the element and use an ohm meter. I can't remember for sure and can't find the values right now, but if memory serves me, you should have 10 Ohms for a good element, but don't quote me on that value, it's been 10 years since I last did any troubleshooting on that part of a Suburban heater. Good Luck !!!

[PARAPTOR]

OKAY now I have the schematic for your HWT and yes the DEL model versus DE has a relay and as expected the 12VDC wiring diagram shows the rocker switch and relay coil. On the 120VAC wiring diagram the actual relay contract is shown. If we can believe that schematic it shows the relay contact feeding the actual 120VAC rocker switch on the tank. So from the 120VAC side if you popped out the rocker switch on the tank you would be able to see if the relay via its contacts was supplying 120VAC to one side of the rocker switch and obviously by pushing the rocker check if that switch is bad. The schematic if correct shows that 120VAC JB as a wiring JB and the actual relay outside there somewhere.

As far as an ohm meter I would think you would only need to check for continuity rather than if it is partially shorted (ohm meter reading). Either have continuity or its toast. I assume you tried the manual reset which is in series with the actual heater element.

This model number explains the various prior posts concerning number of switches on the electrical portion of the HWT. On my 12 gallon DE I only have switch on tank and the actual breaker to shut off the electrical portion of the tank.

I guess I am the slowest at typing

[Bob Landry]

Problem resolved. The reset switch had burned up. Interesting since neither the terminal on the switch or the connector going to is showed any sign of burning or pitting, even though the plastic on the push on connector had some heat discoloration. Probably overdrawing current over a long period of using 30A outlets at campgrounds. I have already had to replace a couple of shore power connectors because of that. My heater does have a rocker switch that is in the on position and I didn't mess with that. I don't know why they would put in a rocker switch and a relay to remove 115V, but then I didn't design the unit. It doesn't matter because before I stick my hands in anything, power gets shut off at the main breaker panel. With the breaker on and the wall switch on, I get 115V at the wire going to the thermostat and 10 ohms on the heating element. I'll go out tomorrow and replace the thermostat and anode and all should be good until the gremlins strike again.

[PARAPTOR]

Good Job and Thanks for letting us know what you found.
If you were referring to the 120VAC rocker switch on the actual tank and the one in series with the relay contacts, I refer to that as the stupid switch, ie before I drain the water out of the HWT I turn that switch off and pin it. So stupid me never accidently turns on the breaker with no water in it.

Now its time to sit back and enjoy a few adult beverages

[Coduckhunter]

Mine has a rocker switch in the panel outside the you have to switch for Ac I did not put the clip in once and bump the switch to the off position spent the hole weekend trying to figure it out. And then my son says dad why is this off.


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[Bob Landry]

I think that for the units that are controlled by wall switches and relays, the switch at the heater serves as a safety switch to insure that electricity is removed from the heater for troubleshooting or component replacement. I don't understand the rational behind only being to control the heater with an exterior switch where you have to go outside and remove a panel to operate it.