Water heater doesn't shut off

BandMedic · 01-09-2012, 08:07 PM

A couple of weeks ago I was winterizing my 2012 Copper Canyon 314RLS after it had been sitting with the power cord unplugged for a week. To drain the water heater, I took the annode out of it and found the water was still hot. Yes, I had left the gas on so I turned it off and thought that was that. There is a switch in the kitchen for the water heater and I'm assuming that's the electric on/off. It's set to <off>.

We're going camping this weekend so I plugged in the camper to get the refer going, and replaced the annode. The water heater is empty and the electic switch is off, but within a few minutes, the bolt head of the annode was very hot. I don't want to put water in it yet because it's supposed to be in the 20s before the weekend gets here.

What do I need to do to get the water heater OFF?

Festus2 · 01-09-2012, 08:22 PM

On some Suburban water heaters, there is a small, black rocker switch located near the bottom left-hand corner of the exterior HW compartment. It may have a tiny cotter pin in place preventing any accidental movement of the switch. If your HW heater has such a switch, press it so that it is in the OFF position. Your model may not have such a switch but if it does, turning this switch off should cut off the 110v supply to the tank.
If this doesn't work, go into your panel, find the fuse for the HW heater and remove it.
If you are heating an empty tank either by 110v or by propane, you will do major damage to it. The tank may already be damaged if it has been empty and being heated for a period of time.
If, for some reason, you can't get the water heater turned off, I would consider putting water in it so as to prevent any further damage.

BandMedic · 01-09-2012, 08:58 PM

Thanks for the quick reply. I'll check for that switch tomorrow morning.

The only time it heated up while empty was today and that was only for a couple of minutes.

Can I put water in just the heater without charging any of the lines? I don't want frozen pipes. It's supposed to get into the high 20s this week.

Festus2 · 01-09-2012, 09:22 PM

I don't think that you can isolate the cold and hot water lines that run throughout your trailer and just put water into the HW tank. You can, however, isolate the HW tank but that isn't what you want.
I forgot about the lower temps and the risk of freezing when I suggested putting water into the tank.
You still can still not plug your unit in to a 110v supply and that will certainly cut off any supply to the HW heater. If you want the fridge cold, run it on propane, or if it is that cold, you may not need to have your fridge on at all! Another option would be to leave the fridge empty and keep what you would put in the fridge in your house until you are ready to go.

SteveC7010 · 01-10-2012, 05:39 AM

If you can look at the backside of the water heater, see if there is a regular white 14-2 residential style electric cable going into it somewhere. If there is, there should be an on/off rocker switch somewhere on the back of the heater. Make sure that is set to OFF.

If it is a 110vac/propane heater, there should also be be a separate circuit breaker for it in the main electric panel. Make sure this is set to OFF.

My last trailer had a Dometic heater and looked like this:

You can clearly see the white 110vac wire entering the top of the heater at the blue strain relief. The on/off switch is to the left of it and is that thick black line with a piece of white foam on top of it. The Suburban heater will similar in appearance.

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