How much water in Tanks to use Tank Heaters

[ksucats]

Not sure which subforum to use so please move if necessary.

Will be using the coach later this month and have read where some have had problems after using tank heaters with empty tanks. So my question - any thoughts on how much water should be in each tank before using the tank heaters. I'll put a bit of fresh water in all tanks but wondering if anyone knows of a recommended amount.

Thanks in advance.

Ron

 

[danemayer]

Hi Ron,

You just need a little water inside the tank to dissipate the heat. But because you don't know exactly where the pads are, or whether the bottom of the tank is perfectly flat, I'd suggest keeping about 5 gallons in each tank. I ran both gray tanks open for about 6 weeks our first winter with tank heaters ON. The gray #1 tank was damaged. Gray #2 was not. Since then when dumping them, I close the valve while there's still a pretty good water flow coming out the sewer outlet - more than a trickle. I dump the gray tanks every other day and sometimes after using the washing machine for a few loads. I'll also try to dump the gray tanks 2 days before I plan to dump the black tank, so the water builds up in the grays to use after dumping the black.

I'm not sure how many people have damaged their tanks - I might be the only one who's admitted it.