Water pump problem

[ElPasso]

I had a glowworm micron with a grundfos multihead G pump fitted by british gas a year and a half ago.
Yesterday the pump was making a noise that sounded like it was struggling to work, a kind of intermittant whirring. I have recorded the sound and it can be heard at http://www.fromsmallpixels.co.uk/pump_sound.wma if it helps.
Very little hot water is getting through to the tank - after 2 hours the some of the radiators were only luke warm.

I am wondering if anyone can advise me on what the problem may be, if it can be fixed or requires a new pump and in either case what kind of price I would be looking at. Or is it something simple that I can sort out myself?

Thanks

 

[LUNAT]

HI


it sounds like pump is dying.replace it before it is completely dead.

 

[mickyg]

sounds more like air to me. Not like the noise of a duff pump. Go check your header tank, make sure water in it.

 

[ElPasso]

Thanks for your quick responses. There is water in the header tank. Some water at least is being pumped through as the radiators became warm and there was some warm water out of the tap.
If the pump does need replacing what kind of price am I looking at?

 

[mickyg]

it doesnt need replacing, definately sounds like air. Possibly blocked cold feed. tie up ball valve, drain some water from system. Header tank level should drop. If not you have a blocked cold feed pipe from header tank.
come back with results