I recently incorporated a temperature controlled 100w ceramic heater lamp, designed for a fish tank, into my water closet, hopefully to keep the manifold and other nearby exposed lines from freeze damage. I always blow the lines and then pump antifreeze thru all of the faucets via the winterize setting in the manifold. But that apparently wasn’t enough for the manifold in the Big Freeze we had here in 2021. In addition, my 5th wheel has an underbelly and I’m thinking of cutting a strategically placed hatch to install another heater of the same capacity while it sits in storage during the winter months. Any thoughts? I have to wonder why underbelly heaters are not built-in. This coming storm will be its first real test. —Ray, 2015 Jayco FLQS 339
What was the low temperature of your “Big Freeze” that evidently froze your manifold last year? Most of the cheap, large box store pink stuff has a -50 degree burst protection; however, I have seen a few -30 degree versions.
If you are using the -30 degree version, temperatures here in the Midwest just plummeted to -15 degrees. However, with a 40-50 mile gust it was recorded at -50 or lower, which would freeze your water lines with this type of RV antifreeze.
I believe the “manifold” you are referring to and water closet is actually the service center and water lines with elbows and “T’s” to divert water to different parts of the coach. This is an example of one in a Class A motorhome. You can see the RV antifreeze in the lines.
You can get RV antifreeze that is rated to -100 degrees. That should eliminate your freezing issues unless there is the possibility that you might not have gotten all the water from some of the lines. Since there are so many valves and lines going in different directions, it is not uncommon to have a line that does not get purged.
One last question I have is why the need for RV antifreeze if you blow all the water out of the lines? If you use compressed air, I would just get all the water out and not put anything else in. Drain the water heater and fresh water tank, and open all the low point drains. Then connect the air compressor dialed down to 40 psi and open the farthest faucet until it blows air, then shut it off and do the rest. Don’t forget the toilet and sprayer, outside shower, and the ice maker if you have one. For the ice maker, remove the filter under the sink and shut off the valve, then cycle the ice maker a few times until there is no water.
You will need to run the onboard pump a little to get the water out of the pump and lines, as the city water hoses bypass the pump when using compressed air. If you get all the water out, you will not need RV antifreeze.
You might also enjoy this from Dave
Can we just open RV’s drain valves to winterize?
Our RV will be stored in Myrtle Beach, South Carolina, for the winter. It has several low-point water drain valves that drain most of the water out. Do you think we still need to have it winterized to be on the safe side? I really enjoy your column; I read it every week. Thanks for any help. —Winfred, 2019 Jayco White Hawk 32KBS
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