Blackwater tank heater lightswitch

[Silver Palace]

Light on switch will not come on. Assume heater is not working. Cant find fuse. All fuses at circuit box ok.

[Alumaholic]

Just like:
A gallon of relative bearing grease; or
One hundred yards of flight line; or
The mail buoy...
There is no black water tank heater.
Ergo, there is no black water tank heater switch.
What is your question?

[Aage]

Originally Posted by Silver Palace

Light on switch will not come on. Assume heater is not working. Cant find fuse. All fuses at circuit box ok.

You don't give the year of your trailer anywhere I can find, so I'll just say that on my '74, there are two smaller air pipes from the furnace that go down through the floor to the fresh water tanks, and the waste tanks.

This practice went on for several years, to my knowledge.

There is very little control over them; turning on the furnace would pump part of the warm air below in order to prevent freezing.

I would not trust that for outside temperatures much below 32F though...

[Protagonist]

Originally Posted by Silver Palace

Light on switch will not come on. Assume heater is not working. Cant find fuse. All fuses at circuit box ok.

I see three possibilities for the light in your lighted switch not to work:
1 - There's no power to the switch, but the switch is good;
2 - There's power to the switch, but the switch is bad, so no power past the switch;
3 - There's power to the switch, and the switch is good, but the light in the switch is bad. You could still use the tank heater this way, until you can replace the switch.

Pulling the switch from the wall and using a circuit tester should tell the tale.

[Moflash]

I assume you are talking about your hot water heater if so the only time the light comes on and stays on for the water heater is when there is a malfunction.When you initially push the on button for the hot water heater it will give one quick flash then go off when ignition occurs.

[Pahaska]

Originally Posted by Alumaholic

Just like:
A gallon of relative bearing grease; or
One hundred yards of flight line; or
The mail buoy...
There is no black water tank heater.
Ergo, there is no black water tank heater switch.
What is your question?

Dig a little deeper before you poke fun. Some recent Airstreams have electrical tank heaters. As far as I know, this is limited to smaller models. I think they first appeared on the 22' models.

[Protagonist]

Originally Posted by Pahaska

Dig a little deeper before you poke fun. Some recent Airstreams have electrical tank heaters. As far as I know, this is limited to smaller models. I think they first appeared on the 22' models.

My Interstate has electric tank heaters on both the freshwater tank and the graywater tank; the blackwater tank is above floor level for improved drainage and so is kept from freezing by the furnace. The rocker switch for the tank heaters has a red light built in, that comes on whenever the heaters are switched on. There's a thermostat in the line, that activates the heaters when the tank temperature drops below about 45 degrees. It will keep the water from freezing, but won't actualy warm the water much. When I used mine Christmas weekend, even with the tank heaters on, the water coming out of the fresh tank was nicely cold.

That's why I understood what Silver Palace was asking about. His is a heater on the black tank, but otherwise similar to what I have on my gray and fresh tanks.

If the switch turns out to be working all right, and the fuse is all right as Silver Palace said, the next culprit to check would be the thermostat.

[Alumaholic]

Thanks for the thoughtful explanation, Protagonist. I knew about the heaters you describe, but had never heard of a dedicated, black-water, tank heater. I apologize to Silver Palace for poking fun.

[AtomicNo13]

My 91 Excella had electric tank heaters factory installed on fresh, gray, and black.

Apparently some from 2008 on have them as well.