Propane water heater

I have a whirlpool propane water heater
It was installed 4-4-13 so it is 4 years old.
I turn it from on to pilot depending when I have family
visiting. Gets very little use.
Recently I checked my propane tank and it was near empty
and had no usage in a long time and had been on "pilot".
The propane guys said this is very strange, you are on pilot and
the water is scolding hot. I called my plumber who installed it and he said it has to the control box.
I called Whirlpool tech line and they said "don't you know that the pilot will heat the water over time.....There is nothing wrong with your controls!

Am I wrong for siding with the propane people and the plumber that say it is the fault of the control box?