Air in Grundfos Alpha 2

[Jon Cottingham]

If he thinks he can service your boiler properly and bleed some radiators in 25 mins you should almost certainly be smelling a rat - most proper boiler services should take longer than that! What boiler do you have?

That's what I though. We have a Worcester condensing boiler (Greenstar?). Its ran very well since it was fitted about 6 years ago.

 

[Jon Cottingham]

Just been on to BG. Another engineer is attending.

 

[Nozzle]

If that small aluminium cylinder with 3 ports in the side and one in the top is what I think it is (an air separator), then it should be mounted above the suction level of the pump, rather than below it.

Just a guess.

Nozzle

 

[Jon Cottingham]

If that small aluminium cylinder with 3 ports in the side and one in the top is what I think it is (an air separator), then it should be mounted above the suction level of the pump, rather than below it.

Just a guess.

Nozzle

Yes that's exactly what it is. I'll mention it to the engineer on Saturday.
Like I said, to be fair the system has ran faultlessly for the best part of three years so far.

 

[Nozzle]

They LOVE it when you tell them what you read on the internet! Be coy about your idea.

Nozzle

 

[Jon Cottingham]

They LOVE it when you tell them what you read on the internet! Be coy about your idea.

Nozzle

Best be careful then. I'll play it by ear. It's not a BG installation though.

 

[ollski]

The very best you could expect is a quote to repipe. Noise and air ingress are almost always from the pump running faster than it can shift the water pulling air through the vent causing more corrosion and restriction. Then someone comes along and turns the pump speed up making the problem and restriction worse. Then you drop the pump speed to quiet it down and it's so clogged up it won't circulate.

 

[Jon Cottingham]

The very best you could expect is a quote to repipe. Noise and air ingress are almost always from the pump running faster than it can shift the water pulling air through the vent causing more corrosion and restriction. Then someone comes along and turns the pump speed up making the problem and restriction worse. Then you drop the pump speed to quiet it down and it's so clogged up it won't circulate.

I hear ya. Hopefully he'll be an approachable engineer with fixing it all in mind.

 

[Jon Cottingham]

So, the long and short of it:

Engineer arrived, diagnosed old pump as shot, replaced in 10 mins, no more noise.

Score.

 

[J_N30]

It's quite rare for a grundfoss pump to become faulty after a couple of years IMO. did you see the condition of it? Any sludge? What colour is the water when you bleed the rads? Glad it's sorted!

 

[Jon Cottingham]

It's quite rare for a grundfoss pump to become faulty after a couple of years IMO. did you see the condition of it? Any sludge? What colour is the water when you bleed the rads? Glad it's sorted!

I didn't get to see it sadly.
Water from the rads is slightly off clear if that makes sense.

 

[D_Hailsham]

It's quite rare for a grundfoss pump to become faulty after a couple of years IMO.

I agree. I have just had mine replaced due to a faulty speed control. It was 20 years old and working perfectly.

It's all very well replacing the pump, but was the pump the cause of the problem or has the pump failed because of the problem? If the second case, the pump will need replacing in another three years. The engineer appears to belong to the parts-changer brigade.