Whats this switch do?

06-27-2012, 07:59 PM

I recently bought a 2006 2720 and I am wondering what this swtch does, its the one next to the furnace thermostat (see attachment). the dealer didn't know what the switch did either so I am at a loss. also does any one know how to use the water heater on electrical power. any help is appreciated.

thanks in advance

Jeremy

Brittany Dogs · 06-27-2012, 08:34 PM

To me, this does not look like a factory installed switch. Wild guess - it is a master switch to cut power to the furnace. The thermostat has an on-off switch in it by pushing the temperature lever all the way to the left past a detent.

But if the previous user would forget to push this lever on the thermostat each time they closed up the unit, the furnace might have been able to cycle on. So my guess is, the previous owner wanted a larger switch that was obvious as to what position it was in (off) when they closed up the unit.

My TrailManor unit will cycle the furnace even with the bathroom wall stowed away (releases the master kill switch) and I had the above concern about the furnace.

So take a look behind the panel and see (or feel) if a wire or two goes from the ivory household switch and goes to the thermostat.

hoverlover · 06-27-2012, 08:38 PM

In the manner of "This Old House": That switch is in case a child gets folded up with the TM, He, or she can activate the TM brakes and thus stop the towing and get rescued.

hillbillyhotel · 06-27-2012, 08:41 PM

Lol, lol
that was to good

MudDog · 06-27-2012, 09:00 PM

As far as the switch goes, as Brittany dogs suggested, I don't think that is standard. Someone added it. Look behind the panel and see where the wires go.

Hopefully that will lead you to what it controls.

It could be the heater as suggested....it *could* also be a way of controlling the water heater on electric from inside the TM rather than having to go outside.

Which is the second part of your question....

Normally to control the water heater on propane gas, you turn on the propane tanks and turn on the water heater from the control panel inside the TM below the kitchen sink (is there a water heater switch on your control panel...the control box on the far left of your picture?). It will then light the gas burner and after a few minutes you should have warm/hot water.

For electric on my TM you need to go outside and open up the water heater access panel on the driver side of the TM. There is a small rocker switch on the water heater. Mine has a cotter pin thru the switch so it is locked in the off position. You would have to remove the cotter pin and flip the switch. The water heater would then power the electric element as long as you have shore power and that switch is thrown.

You need to make sure the hot water heater tank is full of water (and air is purged) before using. You can burn out the electric element very quickly if there is little/no water in the tank.

I personally always run the heater on gas. I can turn it off/on from inside the TM - I can easily turn it on when I need it and off when I don't. The water in the tank will stay hot for quite awhile after it is turned off. It uses very little propane. I'm always afraid I'll forget to turn the electric switch off and then power up at home or somewhere else with the tank empty...not with the risk to me.

Check the wires on that switch...if they seem to be going to the water heater, you may need to flip that switch to turn it on in electric mode.

06-27-2012, 09:10 PM

Thats it!!!! It powers the electric water heater. I was able to trace the wires to find it. Thanks for the help.

Brittany Dogs · 06-27-2012, 09:30 PM

Considering I do exactly what MudDog does, reluctlantly uses the electric portion of the water heater for fear I'll forget to turn the switch off, this is not a shabby modification to have on the inside of the trailer.

The few times I use the electric heating rod on the water heater, I put the needle nose pliers in the power cord compartment in the bumper. I need the needle nose pliers to reinstall the power switch safety pin. So when I break camp and I wind up the power cord (which disconnects from the trailer using the Park Power modification) and then when I try to stow the 30A cord in the bumper, the pliers sitting in that spot in the bumper warns me "hey dummy, turn off the water heater and put the pin back in using these pliers". After I replace the safety pin in the off switch, I then stow the pliers in the water heater compartment.

And yes, I do have things that talk to me like pliers and martini glasses.

**ShrimpBurrito** · 06-27-2012, 10:45 PM

Quote:

Originally Posted by Brittany Dogs

The few times I use the electric heating rod on the water heater, I put the needle nose pliers in the power cord compartment in the bumper.

I do stuff like that too. I have a sheet of printer paper with "FILL WATER HEATER" written in black marker that moves between atop the stove (while in storage) to under the chair (while camping). Has not failed me yet.

Dave

Brittany Dogs · 06-28-2012, 06:15 AM

I'm in the process of making a "DUMBAZZ List" that I plan on taping to the top of the kitchen cabinet. I'm not sure if I'll give it a cleaver name like that or just say it like it is. There are no children around to see it.

**Bill** · 06-28-2012, 06:35 AM

That is a great mod - easy to do, and very valuable. I wish the factory would adopt it. With it in place, you never have to work with that outside switch again - and I hate that outside switch!

If you are electrically handy, and willing to undertake a small additional project, it is easy to make it even a bit more useful by adding some status lights.

If you look behind the panel, you'll find that the switch is mounted on a metal or plastic box, which is about 2 inches wide. Replace this box with a double-size (double gang) box that is the same height, but about 4 inches wide. You'll mount this box off-center, so that the left side of the box, behind the blank panel, is empty, and the right side holds the switch as you see it now.

Get two small 120-volt lights, one red (or yellow) and one green. They are readily available, and cheap. For example, Radio Shack has some that will work, part number 272-712 for red and 272-708 for green. No matter where you get them, you want relatively dim lights so they don't keep you up at night.

Drill two holes in the front panel, one above the other, and centered over the empty half of the box. Mount the red light in the upper hole, and the green light in the lower hole. Connect the two wires from the red light to the two screw terminals on the switch. Connect one wire on the green light to the output (switched) screw terminal on the switch, and the other wire from the green light to the white wire that is already in the box, probably in a wire nut.

In operation, when the red light is lit, it means the switch is off, but power will be applied as soon as you switch on. When the green light is lit, it means power is being applied to the water heater.

This is not failure-proof - you can still switch on the heater when it is empty, which will burn out the element. But it is a great stop-and-think reminder.

Bill