Noisy central heating pump

Marakith

Marakith

Marakith

Associate
Joined
22 Nov 2004
Posts
412
Location
London
Hi there

I just had a new central heating system fitted. An Air Source Heat Pump as it happens.

It replaces our boiler that was under the stairs. Now there's just a hot water cylinder and a load of buffer tanks etc.

The problem is that the Wilo pump we have in there is noisy - it makes this droning sound that is audible in the hallway and even on the landing one flight up.

The irony is that we spent a fair bit of money getting a noise assessment done on the pump to prove it wasn't a noise nuisance not knowing we'd end up with a noisy pump inside the house.

The installer says that's just how loud pumps are. We've tried wrapping it with insulation and also lagging every pipe out of the boiler room but to no avail.

Is the pump defective or should we suck it up?

Thanks!
 
Marakith said:
Hi there

I just had a new central heating system fitted. An Air Source Heat Pump as it happens.

It replaces our boiler that was under the stairs. Now there's just a hot water cylinder and a load of buffer tanks etc.

The problem is that the Wilo pump we have in there is noisy - it makes this droning sound that is audible in the hallway and even on the landing one flight up.

The irony is that we spent a fair bit of money getting a noise assessment done on the pump to prove it wasn't a noise nuisance not knowing we'd end up with a noisy pump inside the house.

The installer says that's just how loud pumps are. We've tried wrapping it with insulation and also lagging every pipe out of the boiler room but to no avail.

Is the pump defective or should we suck it up?

Thanks!
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My thermal store has 2 20+ year old pumps on it, one for tank circulation and one for heating circulation and neither are very noisy. You expect a little noise like a slight hum while they are running but nothing that should be audible with the door closed. If you hear droning or vibration noises it sounds like an installation issue.
 
Marakith said:
The installer says that's just how loud pumps are. We've tried wrapping it with insulation and also lagging every pipe out of the boiler room but to no avail.

Is the pump defective or should we suck it up?
Click to expand...

What sort of insulation did you wrap it with?

Maybe hire a decibel meter to see how loud it is and then ask the manufacturer if that's normal?

Otherwise, proper acoustic insulation on the inside walls of the cupboard might work, although that might be expensive and take up space so probably not worth bothering with.
 
The pure decibels aren't the issue - it's the resonating hum that seems to be.

The engineer has offered to replace the Wilo with a Grundfos. Do you think it'll make much of a difference?
 
Marakith said:
The pure decibels aren't the issue - it's the resonating hum that seems to be.

The engineer has offered to replace the Wilo with a Grundfos. Do you think it'll make much of a difference?
Click to expand...

I don't know, not my specialty. You could try phoning some heating engineers before you do it ... I did once have a Groundfos pump fitted for my central heating and that was fairly quiet if that helps.

Have you checked that none of the pipework is vibrating unnecessarily? i.e. could be secured.
 
It might be worth recording a video so we can get a feel for how bad it is.

I have a heat pump with a buffer tank and 2 pumps in the airing cupboard and I don’t even notice them in that room. They’re not massively noisy and there’s no real vibration or droning.

Is it just the pump itself producing the noise or (as others queried) the pipe work around it?
 
Coran said:
It might be worth recording a video so we can get a feel for how bad it is.

I have a heat pump with a buffer tank and 2 pumps in the airing cupboard and I don’t even notice them in that room. They’re not massively noisy and there’s no real vibration or droning.

Is it just the pump itself producing the noise or (as others queried) the pipe work around it?
Click to expand...
It's definitely the pump. It's not noticeable outside the plant room if we have it on the lowest speed setting. But the installer advised putting it on the medium one.

What brand of circulating pump do you have? He's suggesting swapping the Wilo we have out for a Grundfos.

The issue isn't just with pure decibels - it's the pitched frequency that reverbs through the room and up the house.
 
Marakith said:
The issue isn't just with pure decibels - it's the pitched frequency that reverbs through the room and up the house.
Click to expand...

Can it be re-mounted or isolated better maybe?

For example my living room PC makes a really annoying noise... a better case and better fans would solve it for sure, but I've sat it on a rubberised mat type thing, and a thin layer of polystyrene packageing I cut up and it's helped it a fair bit.....?

Its not loud in terms of decibels, it's just a quiet annoying resonant humming that just irritates the crap out of me so much that I have to play the radio quiet in the background.. it doesn't matter when gaming or watching a film or whatever, as there's sound playing that drowns the humming out...but I can't just sit in silence surfing the web etc.
 
mattyfez said:
Can it be re-mounted or isolated better maybe?

For example my living room PC makes a really annoying noise... a better case and better fans would solve it for sure, but I've sat it on a rubberised mat type thing, and a thin layer of polystyrene packageing I cut up and it's helped it a fair bit.....?

Its not loud in terms of decibels, it's just a quiet annoying resonant humming that just irritates the crap out of me so much that I have to play the radio quiet in the background.. it doesn't matter when gaming or watching a film or whatever, as there's sound playing that drowns the humming out...but I can't just sit in silence surfing the web etc.
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Exactly! That penetrating sound. And when you're aware of it it just won't go away.

I'm hoping when the guy comes back and swaps to Grundfos he can mount it better.
 
How is the pump orientated? There are certain orientations that a pump should not be placed.

Sadly some pumps just whine, I replaced a faulty Grundfos one with an equivalent BritTherm pump and that was terrible.
 
Probably not the same type of pump, but I've had good results from installing a proper mat underneath our shower pump. Went from a defending drone to a reasonable hum when being used.

Although by the sounds of it, this isn't a floor mounted item
 
Marakith said:
Hi there

I just had a new central heating system fitted. An Air Source Heat Pump as it happens.

It replaces our boiler that was under the stairs. Now there's just a hot water cylinder and a load of buffer tanks etc.

The problem is that the Wilo pump we have in there is noisy - it makes this droning sound that is audible in the hallway and even on the landing one flight up.

The irony is that we spent a fair bit of money getting a noise assessment done on the pump to prove it wasn't a noise nuisance not knowing we'd end up with a noisy pump inside the house.

The installer says that's just how loud pumps are. We've tried wrapping it with insulation and also lagging every pipe out of the boiler room but to no avail.

Is the pump defective or should we suck it up?

Thanks!
Click to expand...

It's either defective or set incorrectly. I have a grundfos alpha 1 in a cupboard and I can't hear it when the door is shut.

Oh, I just read what you said. LOL! Yes, grundfos... quiet.
 
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@Marakith can you post some more details of your setup?

Usually heat pumps have the circulation pump in the heat pump itself and you wouldn't normally add any other pumps on the system as they reduce efficiency, sometimes it is required but it usually isn't.
 
b0rn2sk8 said:
@Marakith can you post some more details of your setup?

Usually heat pumps have the circulation pump in the heat pump itself and you wouldn't normally add any other pumps on the system as they reduce efficiency, sometimes it is required but it usually isn't.
Click to expand...
Thanks - yes: this is just the central heating pump.
 
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