If your tankless is Precision Temp call the service number 800-934-9690 and talk it through with Gary. He can explain how to resolve most of your problems. When working correctly it does not use a lot of propane as it only heats when you are drawing water. We have a one handle shower and just turn it off and back on when taking Navy showers. It works much better then the dribble closure which does not work at all with the Precision Temp. If you have the Girard my understanding is be prepared to eat the expense of changing out. I cannot imagine a dealer making the change for either of them at their expense, why should they, you bought a feature :)