I had a megaflow system installed a year and half ago when the gravity system was converted to a closed system - boiler is a Worcester Bosch 19/24. Everything worked fine.
Some months later I had a loft conversion done and added 4 new radiators (one a towel rail). Two issues arose.
One: The radiators in the loft don't get heated until the hot water heating shuts off (or the hot water heating turns off when the water in the megaflow is hot enough - the other radiators in the house all get steaming hot as usual even with the HW heating on). Then the radiators in the loft get steaming hot like the ones in the rest of the house. Throughout the period since the loft was built I've been using the filling loop to top up the water in the central heating system when the pressure drops below 1 bar - every few weeks or so - there was a fair amount of air in the system and there are no leaks in the system.
Two: When the heating system starts to or appears to feed the loft there is a buzzing sound, like a hornet, coming form the airing cupboard where the loft is fed from. I can only really hear it when I'm in the bathroom next to the airing cupboard otherwise it's only very slight. The pump is a Grundfos set to max (3). Is the sound due to incorrect setting on the pump or is it due to more trapped air?
Thanks for any advice.
Some months later I had a loft conversion done and added 4 new radiators (one a towel rail). Two issues arose.
One: The radiators in the loft don't get heated until the hot water heating shuts off (or the hot water heating turns off when the water in the megaflow is hot enough - the other radiators in the house all get steaming hot as usual even with the HW heating on). Then the radiators in the loft get steaming hot like the ones in the rest of the house. Throughout the period since the loft was built I've been using the filling loop to top up the water in the central heating system when the pressure drops below 1 bar - every few weeks or so - there was a fair amount of air in the system and there are no leaks in the system.
Two: When the heating system starts to or appears to feed the loft there is a buzzing sound, like a hornet, coming form the airing cupboard where the loft is fed from. I can only really hear it when I'm in the bathroom next to the airing cupboard otherwise it's only very slight. The pump is a Grundfos set to max (3). Is the sound due to incorrect setting on the pump or is it due to more trapped air?
Thanks for any advice.
