P
Poolman
I have just installed a keston Q37 to open vented system, tank is 4m above boiler and feed and expansion is 28mm teed into return within 2metres of boiler as per instructions. Radiators getting hot ok and hw circuit ok, but boiler is locking out on E37 lack of water pressure. instrctions say min static head should be 9ft which we have easily got that. Bar pressure at boiler is 0.32, instructions say we need a min of 0.6. Any suggestions, am reluctant to convert to sealed system as existing system was installed in the 80,s. poolman