hot water heater pressure drop

Larry Weingarten

Hello: A couple of simple things to double check are; do the cold inlets actually have dip tubes?.. and is the recirc pump actually pumping the right way?.. and does it have a working check valve in the loop? Cold water is getting to where it shouldn't. There aren't too many ways for that to happen. Let us know what you find!

john_27

confusing ....

we recently replaced a 199,500 btu gas fired 100 gallon( 180 gph first hour) with two 65k(60 gph) 130 gallon capacity (combined storage)......and noticed that, as hot water is drawn from the system (one appliance) the outlet temperature of the heaters slowly drops from hot to cold. We don''t think it is a sizing problem. The system has a taco 006 ( in the return before the parallel piping) and is piped parallel reverse return...one difference we note is that the previous hwh had its return piped into a knockout at the base of the heater, while the new installation has the returns piped into the dip tube at the top of each of the new hot water heaters.
Has anyone come across this ?

Tony_8

BTU's

you've reduced your input by a third. That has to have some effect. Is it firing up within 10 degrees ? Are you measuring the temp at the heater outlet or the appliance ?