Hi, this is my first post so please bear with me :-)
I have a potterson conventional boiler in my kitchen (downstairs) and a hot water cylinder in the airing cupboard in an upstairs bedroom. I have a control panel that sets when the h/w and c/h comes on. I have a grundfos selectric 15/50 pump, also in the airing cupboard. Recently this pump started making a loud whiring/vibrating noise (a bit like the noise made by Dr Who's tardis) when the hot water came on at 6:30am ready for baths etc. The boiler still worked, the h/w and c/h still worked but this noise was too much to take each morning.
I turned the pump up to 3 (was on 1) to see if this would fix it but made it worse. I assumed, not being a plumber in any way, that it could be air stuck in the pipes so I drained one of the upstairs radiators to see if this would fix the problem. Needless to say it made it worse!! Now when the h/w or c/h (or both) come on the boiler starts, the pump starts but after a few minutes the boiler starts making a noise like it is boiling which increases and then it cuts out (i assume this is to stop it over heating much like a kettle). The pump in the airing cupboard continues to work (i assume as i can feel it vibrating and changing the speed makes it faster/slower) but the pipes above and below it don't get hot.
Any suggestions would be very welcome before I call an engineer which could cost an arm and a leg, and how could I enjoy my nice warm house with only one arm and one leg?!?