Propane usage

[GoldenFalcon83]

Hi there 🙂
I do 100% full time RVing. I live in the North and the overnight temps can get to -30ish. I have plug in electric heaters and a propane forced air furnace. The propane lasts upto a week. I am wondering if anyone has any thoughts about whether turning the hot water tank off while I'm not using it (about 20 hours a day) will do a significant amount to reduce the propane usage. I have plastic u at all the windows, skirting and under floor heaters as well to help insulate.
Thanks for any input!

[sowego]

We often only turned on the water heater about 30 minutes before we needed it but that was in mild weather.

In extreme cold, down to -25F in our home location we kept the water heater on in electric mode because it kept the tank and lines near the tank from freezing. Even if your tank is gas use only, I'd run it on gas to better protect the unit.

We rented a residential size tank our local gas company would come refill to avoid taking the rig out when it was used up, which was indeed less than a week in extreme cold. In our area they would not come refill anything less than 200G though. Maybe in your area they will refill a smaller one.

[pianotuna]

Hi Kitty,

Heat generally rises. There will be a tiny radiant component from running the water heater--but probably not enough to make any significant difference to the stand pipe.

GoldenFalcon83 wrote:
Is it possible that by keeping the hot water tank on at all times it would help to prevent the water from frezing?
Thanks
Kitty

[Paw_Paw_John]

Golden

You might want to check into the cheap heat system from rvcomfortsystems.com.
If you camp where there is electricity, this system culverts your gas heater into an electric heater. I have mine for over three years and love it. This system heats my 36 foot Mobile suite evenly. Also keeps my underbelly heated. This is a DIY upgrade if you are a handyman.

[Old-Biscuit]

Only the 'hot' water
Cold water is still subject to freezing

Water freezes on occasion........where is is freezing.
Hose from stand pipe to RV???
Hopefully NOT inside RV!

Put water in your fresh water tank and use on-board pump

[GoldenFalcon83]

Thanks to everyone for the replies. My tank is inside the unit and the fifth wheel is definately kept at a reasonable temp inside. The tank lines are hooked up to a water stand pipe outside. The underside of the trailer is heated and there is a radiator inside an insulated box around the stand pipe. The water freezes on occasion in extreme temps but not often. Is it possible that by keeping the hot water tank on at all times it would help to prevent the water from frezing?
Thanks
Kitty

[Old-Biscuit]

Robert78121 wrote:

weathershak wrote:
Check this out. Problem solved

This is what I just did, and it works great and only uses around 400 watts.

Provided you have AC power available
Provided you don't have to pay extra for that available AC
Provided you remember to drain/flush WH routinely
Provided you got one with the small anode rod if Suburban

Workable gadget for propane only (not recommended by either Suburban or Atwood) provided.......

[Robert78121]

weathershak wrote:
Check this out. Problem solved

This is what I just did, and it works great and only uses around 400 watts.

[weathershak]

Check this out. Problem solved

[boogie_4wheel]

My opinion for leaving the WH on vs off greatly depends on where the WH is located. If it is on a FW and located in the basement/storage area, I would leave it on as there is the chance of it freezing.

In my case the WH comes right inside the trailer, and I have an access panel to the rear of the WH for the water lines and bypass valve. I have shut mine off in -14*F weather and it did not freeze, but there was a path for the heat from the cabin to get to it.

[Golden_HVAC]

Old-Biscuit wrote:
What size propane cylinder/tank----gallons??
In those temps you are getting up to a week on propane use then you are doing GREAT? Unless you have a motorhome with a large propane tank

In -14*F temps we had to get a 30# (7 gallon) filled every other day

'Golden_HVAC' makes a good point about the design of RV water heater.
That combustion chamber is wide open and runs up thru tank sucking cold air in/around water inside tank

That's alot of surface area in contact with the water.

In (-)degree temps I wouldn't experiment and just pay for the propane

Looking at the picture above, you can see there is a lot of surface area inside the tank to allow heat to escape into the nighttime air.

If the water is 120 F, then more air will be drafted out, and you will have much more heat loss than if the tank is only 40F. However at night, you will not be able to turn on and off the burner (unless you wake up hourly) to keep the tank at around 40-60F. During the day, if you are diligent, you can cycle the burner for only about 5 minutes per hour, and keep the water in the 40- 60F range to keep it above freezing, and not drop below 30. Because the temperature difference between outside air and tank water is less (at 50F average instead of 130F average) you will save propane. You will have about 1/3 the heat loss with a 50F tank compared to a 130F tank.

But leaving the tank on all the time is the SAFEST way to avoid it freezing and cracking. Otherwise consider draining all the water lines, and then you can shut off the water heater and use portable water jugs for any water use. Then you can lower the inside temps to less than 50F safely without damage to the RV.

However it is much more comfortable to keep it at 65F inside and enjoy the fresh hot and cold water, pay the propane bill, and not worry about pipe damage.

Fred.

[harley-dave]

Try adding electric heating to the water heater. Ours is a 6 gallon Atwood and uses propane or 120v. Eliminate the propane usage.

Dave

[edatlanta]

I have an external 150 gallon propane tank that I use in the winter since I don't want to have to change the small tanks frequently. I'm NOT in the extreme cold areas as others, but I do leave my water tank on all the time. It just isn't worth the risk when it does get down into the teens.

[pianotuna]

Hi,

There are 50 pounds of water in a 6 gallon heater. If the heater cycles to off at 140 degrees F, then it would require a heat loss of about 5400 btu's for it to freeze. The heater is exposed on only one side to freeing temperatures.

If the interior of the RV is kept at comfortable levels then even at -30 it would take a very long time for the water heater to freeze. I know that mine, which is a ten gallon unit, will not freeze at a daily high of -16.6 F during a 5 day trip.

[Old-Biscuit]

What size propane cylinder/tank----gallons??
In those temps you are getting up to a week on propane use then you are doing GREAT? Unless you have a motorhome with a large propane tank

In -14*F temps we had to get a 30# (7 gallon) filled every other day

'Golden_HVAC' makes a good point about the design of RV water heater.
That combustion chamber is wide open and runs up thru tank sucking cold air in/around water inside tank

That's alot of surface area in contact with the water.

In (-)degree temps I wouldn't experiment and just pay for the propane