Hot Water on at night or off?

sgh77 · 10-16-2015, 01:57 PM

We are dry docking (off the grid), does anyone know if it uses more gas to heat water from scratch or keep it hot all night.
Suburban Water Heater. 6 Gallon (22.6L)

**Bama Rambler** · 10-16-2015, 02:02 PM

It's most likely a wash or very close to it. Since you're dry camping I assume you're using propane to heat the water. I'd probably leave it on just so I didn't have to try and remember to turn it back on every time we needed it. You'll waste precious water running some out and then figuring out you forgot to turn the heater back on.

oxcamper · 10-16-2015, 02:08 PM

For your size heater, i would turn it off at night, it won't take long to heat it up in the morning.

phillyg · 10-16-2015, 03:06 PM

I leave mine on 24/7.

OldCoot · 10-16-2015, 03:21 PM

Wouldn't dream of turning it off. It will stay hot for hours, might come on one time for about 5-10 minutes during the night and it will take a lot longer than that to start it from scratch in the morning.

CNYCamper · 10-16-2015, 03:21 PM

Turn mine off if I think of it (about 50% of the time LOL). Don't know if it actually saves much as I don't hear the tank heat up too often when I do leave it running. I do know that if it is off all night the water is still hot in the am.

OldCoot · 10-16-2015, 03:25 PM

Quote:

Originally Posted by CNYCamper

... I do know that if it is off all night the water is still hot in the am.

If it is still hot in the morning, why turn it off?

CNYCamper · 10-16-2015, 03:59 PM

Quote:

Originally Posted by OldCoot

If it is still hot in the morning, why turn it off?

Good point, OC. A few people had mentioned doing it to save energy so I started doing so. I had been thinking that if its still hot in the am then why leave it on all night. When I do restart it in the morning it doesn't take long to shut back off.

OldCoot · 10-16-2015, 04:06 PM

Quote:

Originally Posted by CNYCamper

Good point, OC. A few people had mentioned doing it to save energy so I started doing so. I had been thinking that if its still hot in the am then why leave it on all night. When I do restart it in the morning it doesn't take long to shut back off.

I still fail to see the need to shut it off. With CRS, I'd forget to turn it back on and end up getting another tongue lashing.

sgh77 · 10-17-2015, 12:25 AM

Thank you... advice taken

RamblerGuy · 10-17-2015, 05:15 AM

The water in the heater will cool off and it takes energy to reheat it. It's easy to figure out how much.

1. Run the hot water until the heat, gas or electric, comes on.
2. Wait for the heat to go off.
3. Run as little hot water as possible to measure the temperature.
4. The next morning, measure the temperature again.
5. It takes 1 BTU to heat 1 pound of water by 1 degree Fahrenheit. A 6 gallon water heater has 6 gallons X 8.34 pounds per gallon = 50.04 pounds of water.
6. Propane has about 20,000 BTU's per pound. Electricity has 3412 BTU's per kilowatt-hour. The electric heat is 100% efficient, but the propane heat is not. I'd guess it's about 70% to 80% efficient, so you'd get 14,000 to 16,000 BTU's into the water. The rest goes out the exhaust.

Do this and you can decide if for yourself which way you want to go.

As an example, using a wild guess for temperature drop, say it loses 60 degrees overnight:
60 degrees X 50 pounds X 1 BTU/lb-F = 3000 BTU.
Then 3000 BTU divided by 14,000 BTU/lb = 0.2 pounds of propane.

Just remember that the colder it is outside, the more heat will be lost overnight. The heat loss will be proportional to the difference between the hot water and outside temperatures. (I.E., loss at 30 F is not twice as much as at 60 F.)

PS When the tongue lashing starts after you forget to turn it back on in the morning, just say, "Gee, it's taking longer than usual for the water to reheat" and quietly turn it on before she finds out. It worked for me.

KQ2N · 10-17-2015, 06:40 AM

For one night, I think it's a wash. Longer than that - turn it off.

aceinspp · 10-17-2015, 06:55 AM

I turn mine off. Turn it on at supper to heat for DW shower turn off when she is done. I turn it on in the am when I get up to get our coffey have to walk right by it and by the time we are done drinking the coffey in bed water hot time to get up. Turn off as I pass into bathroom. Just a routine been into for as long as I can remember. Later RJD

**KyDan** · 10-17-2015, 07:12 AM

This is more of a personal preference than a large saving of LP gas I think...
I'm a light sleeper and the WH will probably wake me if it fires during the
night. When we are boondocking we typically wash dishes every other
night. We might only turn on the WH while we're eating supper so there will
be hot water for that chore OR of course if we're gonna take showers.
Otherwise we usually leave it off. In this case I'm pretty sure firing the burner once in 48 hours is gonna use less LP than leaving it on 48 hours. It typically re-fires at least 4 times a day if it's left on. That flue running right up the middle of the WH tank is drawing out the heat when it's not on.

LandJ · 10-17-2015, 07:59 AM

To me this seems like a silly discussion.... we are talking about pennies while we spend thousands on this hobby.

The first time DW has to wash her hands in cold water, any money saved will be spent on dinner out to "warm" her back up.

**KyDan** · 10-17-2015, 08:21 AM

Quote:

Originally Posted by LandJ

To me this seems like a silly discussion.... we are talking about pennies while we spend thousands on this hobby.

The first time DW has to wash her hands in cold water, any money saved will be spent on dinner out to "warm" her back up.

I suppose you might say that but we like to be frugal when possible.
I don't consider a $30+ tank refill to be pennies and I have to lug it to
a hardware store that is 10 miles and several stop lights away.
AND it usually wakes me up when it fires during the night.
To each his own fer sure....

Happy Trails!

Iwannacamp · 10-17-2015, 08:41 AM

I guess I am stupid. First...what is dry camping? I will admit. I am spoiled. I want electric and water. I am also VERY conservative. I just assumed you should turn it off when not using it. I will tell you that we are different. That would be for a different topic.

Sent from my iPhone using Forest River Forums

B and B · 10-17-2015, 08:43 AM

Quote:

Originally Posted by KyDan

I suppose you might say that but we like to be frugal when possible.
I don't consider a $30+ tank refill to be pennies and I have to lug it to
a hardware store that is 10 miles and several stop lights away.
AND it usually wakes me up when it fires during the night.
To each his own fer sure....

Happy Trails!

$30 a tank? I live in Canada and we pay double for everything and I pay only $18 for 30 lbs at Costco. I would say you are getting a bad deal for propane.

OldCoot · 10-17-2015, 08:48 AM

For those that turn them off, I hope you do the same at home where you can save big bucks and not pennies.

Don't forget your home furnace either.

LandJ · 10-17-2015, 08:52 AM

Quote:

Originally Posted by KyDan

I suppose you might say that but we like to be frugal when possible.
I don't consider a $30+ tank refill to be pennies and I have to lug it to
a hardware store that is 10 miles and several stop lights away.
AND it usually wakes me up when it fires during the night.
To each his own fer sure....

Happy Trails!

Point taken, and I did consider the costs and thought the thread might be on to something...

Propane is a lot cheaper for me, I pay $18 on the reservation near my house for 30#. I did the math, assuming the .2lbs mentioned earlier was correct, it is only like 12 cents difference to leave the tank on. Even if I take DW out of the equation, that's not enough savings for me to have to wash my hands in cold water, or wait for the tank to heat back up.

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