Circulating pump making a screeching noise?

[mutley racers]

Hi fellers, How you all doing? I hope most of you guys are off for Christmas. I have just finished today, until Wednesday. But, now in my own house, I have the above problem, and so am in need of some help.

Last week i power flushed my house and re-balanced the system. Everything has been working great for the last week. Then suddenly, a couple of hours ago, i heard a screeching noise coming from the airing cupboard. I have taken it out, checked to see if it was running dry, air in it. And all seem to be ok. Now, it seems that it is only doing it when, both hot water and heating is on. But, if i turn the pump down to 2 speed from 3, the noise stops. But then again, if i turn it on to only heating when on 2 speed, it makes the screeching sound.

Now i just can not figure out what the issue is? Is there a blockage somewhere?

To be honest, i have not got a clue.

Thanks for all your help guys

MUTLEY

 

[Gray0689]

Sounds like pump full of air

 

[diamondgas]

Screetchin pump is usually down to air in my experience Mutley. AIs your system open or sealed

 

[mutley racers]

Hi Gray, thanks for the quick reply. I thought it might have been air too. But, i have been bleeding the pump and water pours out of the vent. What else can i do?

 

[Gray0689]

Turn off then bleed if still same could be impeller is damaged

 

[mutley racers]

Hi Diamond, it is an open vented, Is there another way to get air out of a pump? Am definately moving closer to converting into a sealed system

 

[Gray0689]

Sealed in much better and more economical water heats better under pressure

 

[mcniven]

is there no auto air vent on the flow from boiler near the pump ??? i fitted one of these to avoid this in old systems.

 

[mutley racers]

Thanks fellers. I shall give that a try in the morning Gray. Am too knackered to keep trying now. I shall just put one circuit on at a time.

Am off to smithfields at 4am to get myself a big bird for my christmas dinner. As well as some other little delicacies.

 

[mutley racers]

Hi, yes there is an auto air vent there, but, i would not have thought it would be a good place to put one, on ths suction side of the pump? Are AAV'S able to draw air in?

 

[Gray0689]

Yes they can

 

[mcniven]

Hi, yes there is an auto air vent there, but, i would not have thought it would be a good place to put one, on ths suction side of the pump? Are AAV'S able to draw air in?

one thats faulty might.. if its in your airing cupboard it may be the highest point (above the pump and mv)

 

[mutley racers]

My flow and return pipes run up into the loft from the boiler in the kitchen, then down into the airing cupbaord. So, what could have happened, is, now that i have removed all the sludge, the pump is able to draw more and so is sucking in air. Is that a possibility?

 

[diamondgas]

Time to go to bed mate!! LOL .... up and over open systems can offer many compromising situations especially after major work ... let the system settle over night and see how it is in the morning

 

[mcniven]

is the f+r going into loft area not a bad design when dropping, that cant be good for gravity

 

[Captain.rick]

thread revival, did you sort this op? i got a customer with exactly same problem. i was planning on going back there monday armed with an AAV and a new pump. was going to put AAV in loft at highest point. Should i put it on flow or return?