CH Grundfos Pump

[maddyrocks]

Hi all hoping you can help. CH has been playing up last couple of days, one of the radiators has stopped working altogether, its making a terrbile racket when its first fires up sounds like someting is stuck in the rads and loud gurgling, after 10 mins or so the sounds does go away. A couple of times none of the rads have warmed up but we've had hot water, we've turned it off and left it off for 20 mins or so switched on and theyve come on.

Ive bled all the rads and cylinder, clean water comes out straight away. The 2 port valve is approx 5 years old so im wondering if the pump is on its way out. Ive attached a pic its a Grundfos but cant tell how old. Its on upside down as well ive noticed but would that make a diffrence? Ive turned the grey plastic slot in the middle but not sure what thats for? it only turns between the quarter to and 12 oclock position.

There are 8 rads in the house, boiler is a Glowworm approx 20 years old(i know its ancient but touch wood has never let us down) Its got a tank in the loft and cylinder in the airting cupboard and was powerflushed out in May this year.

Thanks in Advance

Untitled

• maddyrocks
• 21 Dec 2012
• 1

 

[Agile]

How is the tank in the loft?

Is it refilling?

Tony

 

[dcawkwell]

And the clue here is it was powerflushed.

Chances are the pipe from the header tank is blocked and not topping
up the system. You have air in the system.

Is there any water in the header tank?

 

[CBF]

is the pump sitting upright as per your pic ? if so you prob have air in the pump & if it's been like that for a while the bearing are prob knackered, pumps must not be installed upright