How to tell when water heater is at max?

Gdetrailer wrote:
1200W electric heating element can only put out about 4,100 BTU per hr.

Comparing that to the gas burner of the water heater which has a 40,000 BTU input gas burner and at say if the efficiency rate was only 60% conversion the water would get 24,000 BTU of heat..

4,100 electric vs 24,000 gas, you do not have to be a math genus to figure out that using gas is going to heat the water much faster, maintain the hot water temp for much longer even with extremely cold incoming water.

At a min it is going to take 6 times longer to heat the water with the electric heating element that it does with the gas burner.. Typically for my RV water heater it only takes 10 minutes or less to get scalding hot water using gas.. Mine doesn't have electric heating element but I can guess it would easily take 60 minutes or more with electric heating element only..

If you are looking for a long, long, long super hot shower on electric only, you are going to be disappointed.. Since RV electrical systems have considerable electrical capacity limitations like limiting the water heater electric element to about 1200W it is slow to heat, slow to recover and extremely fast to lose temperature when water is being drawn out..

A couple of things you can do to make the hot water in your shower last longer..

#1.. Take a "Navy" shower.. Turn on water to get wet, turn off water to lather up and turn on water to rinse off..

#2.. Do what I do, turn on water JUST ENOUGH TO GET A LIGHT SPRAY from the shower head.. Lets face it, you are not in a sticks and bricks with an unlimited supply of water and you are not going to get a shower that pins you to the shower wall if you want a long, long hot bath.. The faster you use your supply, the shorter amount of time you have to use it and the faster it goes down the drain.

Using this method, I can get a 20 minute shower with no noticeable drop in temp and 5 minutes later the next person can get a shower..