tankless will usually cause you some grief and
you sepnd the next few years trying to "tweak it"
hopeing to recoup your investment......
its only normal when you got about a 1/2 inch or less
coil for the ot side and a 3/4 cold full line fighting eash otehr through
tha tpressure balanced valve.....
then when the coil begins to lime up, its all over