That is what I thought, that the CV was more of a function for Winterizing. The CV is in the Water Heater outlet and I have a hand valve for the by-pass on the inlet. For now, I am leaving out the internal parts. The O-Ring was broke that goes on the poppet and the retainer that hold the spring onto the poppet is missing. I will pick up a spare CV or a shut-off valve, just in case I have to put antifreeze in the water system. But as long as I keep out the north during winter I should be OK for now. Thanks everyone for your input. Gary