John. I have attached the schematic from the Santon cylinder installation manual. It shows the balance cold water connection tee to come after the combo valve and PRV and before the EV tee. I have also attached a photo of the actual set up reflection those instructions with the balanced out after the combo valve and PRV. Are you saying there should be a non return valve installed on my system somewhere, Im not convinced I have one fitted? can you advise from my photo?
On your second query, I think the PRV combo valve was intec or intatec. How would I know if the PRV was drop tight.? Once again, would increasing the size of the expansion vessel to 25l (6l) greater than I currently have alleviate the pressure causing the Pressure release valve to open? I notice when the the boiler is on and the tundish is leaking, the pressure via my little Schrader gauge literally tops out and is at least 6-7 bar? its set to 3 bar when empty.
On your second query, I think the PRV combo valve was intec or intatec. How would I know if the PRV was drop tight.? Once again, would increasing the size of the expansion vessel to 25l (6l) greater than I currently have alleviate the pressure causing the Pressure release valve to open? I notice when the the boiler is on and the tundish is leaking, the pressure via my little Schrader gauge literally tops out and is at least 6-7 bar? its set to 3 bar when empty.