RV propane water heater

We have the propane/electric WH and I seldom turn the gas heater on. Our electric WH usually provides enough hot water for DW and me. This is the only WH I've ever had i an RV that works this way, on my previous RVs I had to run the gas heater when camping.

Old-Biscuit wrote:
20 mins of heating every 3-4 hrs. OR 30 mins of heating prior to use????

Another way to look at it:

Having hot water whenever you want it? OR waiting 20 - 30 minutes to get that hot water?

RV water heaters refire at roughly 110*F and then shut off at 140*F....they can cycle every 3-4 hrs for 20 mins. when not being used.

OR you can turn it ON 30 mins before you want hot water

Personally.....ours is on when we set up until we tear down for travel.
I want hot water when I turn faucet on damn the pennies spent. But that is personal choice.

20 mins of heating every 3-4 hrs. OR 30 mins of heating prior to use????

DSDP Don wrote:
I think several missed what the poster was asking.

He's asking is it more efficient to let his water heater run all day, which means it will come on every so often to maintain temp, or turn it on just before his shower and then off when he is done.

Personally, I think it would be more efficient to leave it running. They are well insulated and will hold heat for quite awhile.

You would actually be thinking wrongly, although it may not be enough of a difference to really notice one way or the other.

The heat loss from the water heater when not using hot water is basically just the heat loss through the insulation. This is proportional to the difference in temperature between the hot water and the surroundings. If you let the water cool down, the average temperature difference is lower, and so the amount of heat that is lost for a period of time is lower. Assuming you start and end at the same condition (i.e. the tank is full of hot water ready for use), the energy (propane) you put into the water to heat it must be equal to the energy it loses to the outside world.

This basic theory also explains why it is more efficient to turn your house thermostat down (or up in summer) when you leave and return it to the desired temperature when you return, rather than keeping the temperature constant.

The water heater is probably more efficient at heating water than the stovetop. However, if you only need a few cups of water for coffee, the stovetop will use less propane because you're heating a few cups (less efficiently) rather than a few gallons.

I think several missed what the poster was asking.

He's asking is it more efficient to let his water heater run all day, which means it will come on every so often to maintain temp, or turn it on just before his shower and then off when he is done.

Personally, I think it would be more efficient to leave it running. They are well insulated and will hold heat for quite awhile.

Not a Clue wrote:
We have a propane only WH. We turn it on when we get set up and turn it off when we are leaving. It takes so little propane I can't even tell the level has changed.

That's what I do and I have the same results on the propane use. In addition, I have hot water with which to wash my hands, etc. no matter when I need to do so.

Let's see. Running microwave when gen is on to charge batteries actually uses more fuel since the load on the gen goes up with the use of the mwave. Maybe not noticeable but there is no such thing as a free lunch.

When we were dry camping in our former coach with propane/electric water heater we turned it on 15 minutes before we expected to use it. For normal warm water to wash hands etc the tank usually would be fine even though it had been off of a few hours, it is very well insulated, thus you are not heating from cold each time.

We were less interested in the cost of propane than in preserving it so we didn't have to break camp and drive to town to refill. In the scheme of total cost of operations propane is small potatoes.

We have a propane only WH. We turn it on when we get set up and turn it off when we are leaving. It takes so little propane I can't even tell the level has changed.

We do the same as we do in a house. We keep it on electric and always have hot water available. You may use more power to keep reheating the water than you would to just keep it hot.

rjxj wrote:
We only run it for showers and use a kettle to boil water for dishes, coffee etc.

We do the same except microwave water to clean dishes. Need to run generator to charge batteries when off grid or use electricity in a campground so there is not extra cost to heat cleaning water.