My present Honeywell 3 port valve V4073A1039 is probably on its way out as I noticed that some radiators were getting a bit warm when only hot water should have been on during last summer.
My question is: What is the difference between V4073A and V4073 when it comes to replacement. I note there are a lot of New units advertised on E-Bay at competitive prices but the packaging just shows V4073.
My question is: What is the difference between V4073A and V4073 when it comes to replacement. I note there are a lot of New units advertised on E-Bay at competitive prices but the packaging just shows V4073.