Singing noise related to water pump

[benawhile]

Since our central heating system was upgraded in October we have noticed a singing noise in the house when the water circulating pump switches on. It is a new Grundfos UPS2 15-50/60 pump with 3 speeds. Reducing the speed reduces the noise but it doesn't go away, and we need to use the maximum speed to heat the house effectively.

The noise sounds like a musical tuning fork. It comes from any part of the house where there are pipes or radiators, as well as from the pump, but is not easy to pinpoint. It is not loud, just annoying. How loud it is depends on where you are in the room and what direction your head is turned. It is as though the noise from the pump transmits to the water everywhere in the system.

The system works well otherwise, there are no other clues, although there is a slight unrelated whistling from the boiler flue which is being investigated.

A Magnaclean filter was fitted and has removed about a cupful of black rust already.

 

[ShaunCorbs]

try shutting one trv at a time off unit the noise is gone

 

[SimonG]

What did the upgrade consist of?

Was the system balanced afterwards?

 

[benawhile]

try shutting one trv at a time off unit the noise is gone

That is a very interesting suggestion and I will try it. There are 6 rads in the system, plus two others that are in an unused and uninsulated conservatory that are always shut off. There is no bypass as yet, so what is the max no of rads I can shut off at once?

 

[benawhile]

What did the upgrade consist of?

Was the system balanced afterwards?

Original system was about 30 yrs old at least, no time switch, one thermostat operating one pump. 5 rads, hwc, open vent, one Rayburn coal fired boiler. It had been unused for at least two winters.

Our "upgrade" last October was to replace the boiler with an Intergas boiler, plumbed in at a different location on exterior wall, but retaining the open vent, and add a timer, new pump and magnaclean filter, and add a radiator to the kitchen where the Rayburn was.

It probably hasn't been very well balanced as some of the balance valves are still seized. They look as though they are all full open. We have already removed about a cupful of sludge from the Magnaclean. In December we found air in the top half of the upstairs radiators and bled it out and it has not re-appeared yet.

 

[chris watkins]

A 15/60 on max, feeding 8 rads, there has got to be a problem there with restricted pipes.

 

[townfanjon]

When the pump was changed, were the pump valves changed or just closed .

 

[Welder]

Did the installer have an apprentice who was a 'The Voice' contestant who got left under the floorboards?

 

[townfanjon]

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[Pickwickpick]

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What's PH?