tankless water heater

thanks for the responses. I'll have to get back tomorrow on the brand in my trailer as I am away from the trailer right now. Not sure how the check valve would work as the on/off button on the shower head would work as a check valve (from my way of thinking). The insulation sounds worth a try -- I'll check tonight how hard it will be to add the insulation. I can easily get into the back area of the heater unit.