My complex winter storage plan without antifreeze

[Bill Sprague]

Some of this might be useful and maybe not.   It dropped to 32 for the first time this week.  

If it freezes ……

Our motorhome is stored under a roof with 30 amp power in a commercial storage facility.  The HydroHot electric element, refrigerator, battery charger and a dehumidifier are on.  The furnace is set to 50.  Monitoring the Aladdin indicates that power consumption can vary from about 8 amps to about 22 amps if everything decides to run at once.

It normally stays above freezing here, but occasionally can get as low as 20 degrees.

I could winterize with the pink stuff.  It is reliable, cheap and I’ve done that. Instead, I like to keep the motorhome ready to go and hope for opportunities to head out.

There is a risk that the power could fail, the circuit breaker could trip, the shore plug could unplug or the Hydro Hot electric element could fail.  In fact, all that has happened, but I’ve caught it in time to prevent buying a new $8k furnace.

Gradually I came up with a plan to cover what I think are the primary risks.  It’s complicated.  Stop reading if you are in a hurry to do something.

We live near Tacoma.  To keep the interior dry and free of mold and mildew we always have a dehumidifier running.  I keep it in the shower with the shower door open.  Attached is an “optional” hose so that the water drains into the shower drain.  A byproduct of the dehumidifier is a little heat for the interior.  Even after 9 years, out motorhome always has a 'fresh' smell when we walk in.

I bought a 200 watt ceramic heater to back up the Hydro Hot element.  To do that, I installed a “utility” outlet in the HydroHot bay.  The outlet is wired into the 120volt feed to the existing electric element.  The heater is plugged in with a thermostatic freeze cube intended for and made by a plumbing heat tape company found at Lowes.  The heater does not come on, unless the temperature in the bay drops to near freezing.  That shouldn't happen unless the HydroHot element fails (again).

I did the same thing with another additional utility outlet behind the “hidden” tank bay door where access to the wiring for the “basement” outlet is accessible.  Now, if the HydroHot element, the tank bay heat exchanger or its thermostat fails, the freeze cube will turn on the second 200 watt heater.  

A third 200 watt heater is plugged into the existing “basement” outlet with a freeze cube.  That area is normally kept warm by heat coming off the inverter/charger.  Should the power to the motorhome fail and the inverter stop “glowing”, the extra 200 watt heater will come on and keep the bay above freezing.  

If the shore power is disrupted at the plug or there is a general power failure, the Onan is set to auto start when the batteries are only moderately low.  Because the dehumidifier will be running off the inverter, the batteries will draw down quickly enough that the generator will start before anything gets very cold.  The genset is not set for auto shutoff.  That serves as an “alarm”.  I expect that the manager at the storage center would call ifhe hears it running.

No plan beyond a complete “pink stuff” winterization is perfect.  I think I have improved my odds against freeze damage, reduced single point failure modes and made it easier to use the motorhome in the winter.  The cost for the three small heaters, freeze cubes and utility boxes was about $100.

[Sean Donohue]

Bill, Not sure if you were influenced by my posts about not using the Pink stuff, but I hear good bourbon is a great alternative. Just kidding. I did not notice if you have plans to drain the water from the low points and or blow out the lines? I do this with the theroy there has to be water to freeze to burst or damage a line. Also, manually pumping in Pink stuff to the Hydro Hot(mine is Aquahot so I am not sure if it is possible) might be another thing to consider. The other place water can cause problems and it did for me is there is on the water pump is a plastic cap looking filter that cracked when the freeze hit that I now remove after I drain and blow out the lines. I did all this last year and survived a few good cold snaps back in the 7000' of NE AZ. I do know that yours and my procedures fly in the face of most others here. I would state that plan you have is likely to work.

[Bill Sprague]

"Not sure if you were influenced by my posts about not using the Pink stuff, but I hear good bourbon is a great alternative. Just kidding."
No, not at all.  I did most of it last year.

"I did not notice if you have plans to drain the water from the low points and or blow out the lines?"
No.  My reasoning behind all this is that the motorhome is always ready to go, including the ice maker.

"Also, manually pumping in Pink stuff to the Hydro Hot(mine is Aquahot so I am not sure if it is possible) might be another thing to consider."
HydroHot and AquaHot are versions of the same thing.  On my version the plumbing on the back has a lot crammed into a tight space, but valves and fitting might be easy to install that would isolate it from the rest of the system.  

"The other place water can cause problems and it did for me is there is on the water pump is a plastic cap looking filter that cracked when the freeze hit."
That screen is part of the pump kit.  I had the same on previous trailers.  Mine is mounted on the bulkhead between the heated tank bay and heated storage bay, so I don't expect it to freeze.