Holding Tank Heaters

[Skip76]

We have a relatively new 2019 Jayco Greyhawk 31F. We are unexpectedly using it where the nights are going into the mid 20s and days in the 50s. I wanted to use the holding tank heaters but read not to use them if the fresh water tank and feed lines are empty. As we are hooked up to city water, two of my three tanks have freezable water or substances in them. Sooo, to use or not to use with the fresh water tank and feed lines empty and one switch turning on all tanks and line heaters. Found discussions on their use with all three tanks being used but not with the fresh empty and others full. Thoughts?

[Jagiven]

We do not have an enclosed underbelly nor tank heaters. We commonly camp in those temps and never have an issue.

You do need to disconnect the fw hose at night. Or it will freeze, small thermal mass. I recommended filling the fw tank for night use. It does not need to be full.