Tank (Black Grey) Heaters

Question

Our new-to-us 2008 Coachmen Class C came with Tank Heaters - according to the PDF brochure.

If the motorhome is unplugged from shore power (on battey) and if I flip the coach switch marked Heater, the indicator light goes on, but my coach battery voltmeter doesn't drop at all.

No change.

I'm guessing that means the pads are not working anymore. (Or are there heaters that only work on 120V?)

Since we would like to do some cold weather camping, I'd like to see if the fix is easy.

Has anyone messed with their tank heater pads?
I'm wondering if someone else who's been in this spot would say "Don't waste your afternoon..." :)

ductape · Answer

Good ones have a built in thermostat and only draw current below the set temperature.

ron_nielson · Answer

There are heating pads that are 12V, heating pads that are 120V and heating pads that are both 12V and 120V. So you could have any of them.

One thing to know about heating pads is that most of them don't work unless the tank pads are below a certain temperature. You may have the switch turned on, as indicated by the light, but no electricity passes to the pads until they're cold enough to turn on.

Figure out what brand of pads you have, look up on the internet what their turn on temperature is (remember that's NOT the outside temperature) and then decide if you need to do some exploring.

old-biscuit · Answer

Sounds like yours are 12V DC (light came on when not connected to AC Power)

They are typically controlled by a t-stat on the heat pad.
Sensor detects temp below 44*F heat pads are activated......then deactivated when temp above 64*F

Indicator light is so you have a visual that they have 'power'.
On/Off switch should be OFF when ambient temps are above freeing and/or if tanks are empty. W/O liquids in tanks......pads can damage tank

You could dump bags of ice down toilet to chill black tank or buckets of ice water down sink drain and test pad amp draw

goostoff · Answer

Are you sure you are turning on the tank heaters and not the ignitor for the water heater to run on gas? My switched are both clearly marked. The water heater ignitor says "heater" and the tank heaters say "tank heater"

time2roll · Answer

Do you have access to see the heat pads?

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Tank (Black Grey) Heaters

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