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We have conventional Greenstar Ri central heating and hot water system with tank. When heating water only, it seems to take forever for the water to reach the target temperature of 60 deg C set on the tank stat. The pump works fine, but the boiler is modulating to the point that it only heats for maybe 20 seconds before reducing heat - it sounds as though it almost cuts right out, though the pump continues to run.
Once the tank water temp reaches say 55 degrees, the return isnt going to be less than this value. So if condensing boilers are supposed to maintain delta T of 20 deg C, how is the system ever going to reach target of 60 degrees unless it runs at 80 deg C?
From memory this is less of a problem in winter ironically, presumably because with the rads on, delta T of 20 is easier to maintain.
Any thoughts?
Once the tank water temp reaches say 55 degrees, the return isnt going to be less than this value. So if condensing boilers are supposed to maintain delta T of 20 deg C, how is the system ever going to reach target of 60 degrees unless it runs at 80 deg C?
From memory this is less of a problem in winter ironically, presumably because with the rads on, delta T of 20 is easier to maintain.
Any thoughts?
