Hi experts. I've moved into a new home that has a rayburn oil fired range that heats everything, well sometimes! The previous owner had the heating/HW running continually and I have discovered that the HW cylinder was on max and the 3 way diverter was defective. I've replaced the motor on the 3 way valve and proved it moves ok by turning the cylinder stat up and down until it clicks. I now find that the pump is running continuously (timer set to on) and the boiler cycles on and off probably due to the outlet getting too hot. I feel I have a problem with either the 3 way valve or the pump yet both appear to be working ok. The valve moves and it appears that the flow changes from tank to rad. I can feel the flow in the pipes so the pump is doing its thing. I've tried changing the pump speed to no avail. Changing the pump is the easiest job if the isolation valves are tight. Anyone any bright ideas before I get a new pump?
