Water Heater On or Cycle?

jplante4 wrote:
I would be able to figure this out using my extensive thermodynamics knowledge :B, but I'm missing a piece of information.

Is it better to leave the (propane) water heater on all the time while parked, or shut it off after you're done with the hot water and turn it back on when you'll need hot water again.

As far as cycling goes I figure it uses 4000 BTUs to get back to temp (50° temp rise, 80 pounds of water) and a gallon of propane contains 90,000 BTUs, so I use about .05 gallons for each cycle.

The piece of info I'm missing is what's the duty cycle of the heater in standby? In other words, at what temp does the burner kick on and off?

This is the kind of stuff that enters your head when you're sitting around all day at a campsite.

First off it's a 30*F rise
T-stat recloses at 110*F and opens at 140*F

Duty cycle is roughly 1X per hour

There's your missing pieces.....so figure away


For me............WH goes ON when we set up and stays ON until we tear down to relocate.

I like HOT water when I turn faucet hotside on....that is why I have a water heater.