RV anti-freezing temperature switch

I bought a RV that I want to keep from freezing. I bought a Thermo Cube TC-3 that was suppose to turn on my 500W heater at 35 degrees and turn off at 45 degrees.
https://www.amazon.com/Farm-Innovat...&qid=1572449250&sprefix=heatit,aps,213&sr=8-7

It is below freezing now, 27 degrees F, and it didn't work. The only thing that saved my water system from freezing is that I set the propane heater to come on at 33 degrees. I have 30Amp service where I park my truck and camper and prefer to use that for heat instead of propane.

I looked for other similar devices on Amazon but the other device is also unreliable. It seems that 20% of these temperature enable relays do not work or don't work at the correct temperature.

This is an alternative but it gets 1 star reviews by 20%
https://www.amazon.com/HEATIT-Freez...&qid=1572448767&sprefix=heatit,aps,213&sr=8-3

What I am looking for is something simple and reliable.
I don't want to buy a PLC just to turn on and off an AC relay.
I know someone has solved this problem before.
I looked at Omega but they didn't have anything this simple.

BTW, I am posting less because I go boondocking. No TV, internet, electricity, water, cell service but perhaps one rock&roll radio station.

https://www.amazon.com/WILLHI-WH143...=low+temperature+switch&qid=1572451249&sr=8-1

$29 from amazon

What about something simple like this?
https://www.amazon.com/Honeywell-Pr...mostat&qid=1572452395&rnid=468240&s=hi&sr=1-1

DIY grab a little klixon and wire you up a receptacle

https://www.amazon.com/Thermostat-S...ocphy=9023746&hvtargid=pla-560117259499&psc=1

Edit:
Can't believe you bought that thing, did you not see the poor chicken coop fire pics!

Thanks, I went with g.mccormick's first suggestion. It cost more but I can adjust it to compensate for any errors and modify the temperature band. 35-40 degrees would be better than 35-45 degrees.

I'm too late. I bought one of those thermocube socket adapters from Atwoods (local farm/ranch store) and used it to run the heat tape on my home water well head for a couple of years, then it died and left me a nice frozen fountain as a welcome home gift.

I have used a handful of cheap temp switches for panel thermal management that have not let me down:

https://www.automationdirect.com/ad...nagement/thermostats_-a-_hygrostats/011409-00

Combined with a relay (if you need a lot of amps) and a small box with receptacle and cord it should work, but it sounds like you found something.

OkiePC said:

I have used a handful of cheap temp switches for panel thermal management that have not let me down:

https://www.automationdirect.com/ad...nagement/thermostats_-a-_hygrostats/011409-00

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That is a backup option but the switch tolerance is +/- 7 degrees.
I understand that is cheap but 20 years ago I worked on a project that needed temperature compensate electronics. We used a small temperature sensing transistor that was accurate to within 2 degrees or better. I remember verifying it using a heat gun and ice from the freezer.

Christoff84 said:

What about something simple like this?
https://www.amazon.com/Honeywell-Pr...mostat&qid=1572452395&rnid=468240&s=hi&sr=1-1

Click to expand...

That was to be my suggestion. I have a few of that type around my building for different heat zones.

Gene Bond said:

That was to be my suggestion. I have a few of that type around my building for different heat zones.

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The first two reviews say "fire hazard" and "don't waste your money"
I can see where to set the turn on point but not the turn off point.

We have a thermal chamber for testing our motion controllers. I am going to see what temperature the Thermo Cube turns on at. Any device that advertises that it turns on at 35 degrees F should be accurate because if it turns on at 32 degrees f, or lower, the water can freeze.
What is really bad is that the Thermo Cube appears to be made in the US.
What happened to quality control?
Why is there so much garbage for such a simple application?

have a look at this self-regulating tape
https://www.amazon.com/EasyHeat-2102-Freeze-Heating-Cable/dp/B002KT5ZPO/ref=asc_df_B002KT5ZPO/?tag=bingshoppinga-20&linkCode=df0&hvadid={creative}&hvpos={adposition}&hvnetw=o&hvrand={random}&hvpone=&hvptwo=&hvqmt=e&hvdev=c&hvdvcmdl={devicemodel}&hvlocint=&hvlocphy=&hvtargid=pla-4583932699515360&psc=1

I have use similar taped for many years with out problems but it will only work if you have power to it
most people I know that have RVs winterize them for storage then you don't need to worry about power. if you don't know how to winterize it check with a local RV dealer ad they can show you how

I use a panel heater thermostat that needs to be set at 60°F in order to maintain 40°F. Ridiculous.

GaryS said:

most people I know that have RVs winterize them for storage then you don't need to worry about power.

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I bought a 1Ton DRW with a Arctic Fox 990 last summer and I have been using it every other weekend. The AF990 will be on the truck 99% of the time. It is like a class B only more portable. I went out last weekend even though it was freezing. I plan to use it all winter. On top of that, I want to explore some roads where a 4x4 is required. There are lots of logging roads around where I live. The Gifford-Pinchot National forest is near by.

When I have it parked at the office, I have electric power. A small 500W heater should keep the camper from freezing. The 500W heater will only raise the temperature to about 22 degrees F above the outside temperature but that is enough to keep the freezing unless the temperature gets abnormally cold. The problem now is that the heater is on all the time wasting energy because my Thermo Cube doesn't turn on when it should.

GaryS said:

if you don't know how to winterize it check with a local RV dealer ad they can show you how

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Yes, but I can read and following instructions. Plus there are lots of YT videos. However, I didn't spend all that money just to let the truck camper sit.

I am serious about this. This old dog can learn new tricks. I have been learning all my life. This is easy stuff compared what I normally do mentally. I won't like getting on top of the camper to apply the Dicor sealant.

Any reason you do not just buy a small air compressor to carry and blow your lines out when you are done? It takes very little time and a pancake compressor should do it.

Regardless devices fail. If you put that much trust into a cheap device, you are asking for trouble.

I apologize is you took what I said about getting help winterizing your RV
but I live just a little north of the Mason - Dixon line and I find the when you get much below that line they don't winterize their RV's. I just doesn't normally get that cold down their. I have even heard of some dealer in the south that don't know how to do correctly.
I would tend to stay away from heat taps in a stored RV as your only means to freezing protection things happen power goes off ( and always at the most inopportune time) then you end up repairing the damage
If as you state you are going to use it over the winter than a heat tape on both the supply line and the discharge line. and even a tank heated would be recommended