CSV Placement

I recently installed a tankless water heater. I now notice the well pump cycling affects the temperature when taking a shower and would like to put in a csv, which I just heard about. Will this help the function of the tankless water heater? Where should the csv be placed? Thanks, Jim

Yes a CSV will solve this problem. The smaller the pressure tank the better though. This is because you have to wait for the tank to empty and the pump to start before the CSV can give you the constant pressure the heater needs. The smaller the tank, the sooner this happens. I don't recommend any smaller than a 4.4 gallon size tank, which holds 1 gallon of water.

they just replaced the pressure tank. It's the "usual size". We had it put underground next to the well head. Are you saying the pt should be smaller than the usual size? The well output is listed at 10 gpm. I believe it is a 20 gallon pressure tank. Is it necessary to have a smaller tank with the CSV or can the drawdown be less (ie set the low point at 55psi rather then 40psi)

20 gallon tank only holds 5 gallons of water. That tank is already too small without a CSV. That size tank will work fine with the CSV. The only problem is that the CSV must be installed before the pressure tank or any faucets. With an underground tank, that just means you probably have to install the CSV in the well.

they left the shut off, switch and union above groungd in the well cover. I should be able to place it there. I think it is a 20 gal bladder tank. So the CSV is before the PT....Thanks, Jim