I have a single cold water tank in the roof, an indirect hot water
cylinder and a wall mounted Potterton gas boiler.
The central heating pump has a standard 1" pipe into the bottom, and a
converter to a 1/2" pipe at the top. Actually, the pump seems to be
mounted upside down...
Anyway; the bottom, 1" pipe circulates the centrral heating water AND
the water into the cylinder coil. Both the cylinder and the main CH
pipe have electronic valves on them.
The problem: periodically during the day what sounds like a large
volume of air enters the system. The hot water vents into the roof
tank to truly alarming noises.
I've changed the cylinder thermostat; changed the programmer; taken
all the radiators off, flushed them through and refilled the system.
But the problem remains.
Can anybody advise me please?