I have a home with a Bosch 125 Tankless waterheater. The heater works fine after the water gets to the fixture but it seems to take forever for the hot water to start flowing. The delay on the two fixtures closest to the tank is acceptable but the fixtures at the other end of the house have to long a wait for hot water. I have a small 2.5 gallon electric heater I would like to install in the hot supply line to provide the initial supply of hot water. Originally I was going to install the small tank heater directly in the hot supply line close to the fixtures but now I wonder if I should use a tempering valve instead? My concern is that one of the fixtures is a shower and I’m thinking that the water temperature would drop as the small tank emptyed even though the main heaters water would be available. My thoughts are that by using the tempering valve I could eliminate or minimize this drop.
My questions are where should the tempering valve be installed and does anyone have a recommendation as to a make, model or manufacturer of the valve?
Replies
I think I would install a small tank right next to the tankless heater and a recirculating loop to the remote fixtures. It shouldn't be too difficult to set the thermostat on the tank heater to the same temperature as the output from the tankless, thus avoiding any temperature change.
Of course, you might want the tempering valve anyway, for safety reasons.
Thanks, I hadn't thought of that. However it would be a real pain to run the line for the loop without tearing up half the house. I've got the tankless set fairly low so we don't have to blend much at the fixtures, our laundry and dishwasher make their own hot water so we don't need to set the waterheater for these high temperature needs.