New Combi Boiler Hum

[panthro]

We had a new Worchester Combi put in our loft yesterday, before agreeing to put it in the loft we asked the plumber if there would be any noise issues in the bedrooms below. He said there wouldn't be.

After installation, in the bedrooms we can hear a lo whir when the heating clicks on, which slowly builds, but the real issue is when a hot tap goes on, there's an audible hum.

Is this normal? What can be done about it? Thanks!

 

[Dan]

All boilers make a noise.

Things with the boiler are perhaps set it on a timer so it's off during the night heating wise. Turn the water preheat right down so it's not needing to heat that up. If it has one.

You could also stick more insulation down above the ceiling if your bedroom. Put loads down around where pipes come in and out ceiling etc. (Loft Side though).

Don't cover the boiler or anything directly connected to it mind.

 

[ShaunCorbs]

Yes normal the noise your hearing is the boiler ramping up to full heat eg when your opening the hot tap

Nothing can be done sorry, is your loft insulated (might cut down on the sound)

is your loft boarded with a light and loft ladder (required for the warranty)

 

[townfanjon]

I dont do Worcesters but have always thought they were pretty quiet , I would ask your installer to come back and have a listen .
We all have different tolerances to noise , some may think its quiet , some will say its noisy .

 

[Chuck]

After installation, in the bedrooms we can hear a lo whir when the heating clicks on, which slowly builds, but the real issue is when a hot tap goes on, there's an audible hum.

Your description of an 'audible hum' when running a hot tap might be a form of 'water hammer, i.e. the pipework vibrating. If this is the problem, getting the installer to add some more clips / support to the pipework will be an effective fix.

IIRC, the default circulation pump factory setting on Worcester boilers is 'maximum', which is unecessarily high and noisy in many cases.

Are you able to record a sample of the noise, e.g. on your phone, and provide a link to the sample so we can hear it for ourselves?

 

[panthro]

Thank you all so far, much appreciated.

I've tried capturing some audio, but its such a low frequency hum i'm finding it hard to capture.

IIRC, the default circulation pump factory setting on Worcester boilers is 'maximum', which is unecessarily high and noisy in many cases.

Oh so this can be set - do you think it will help with the hum? The water hum is much much louder than the heating hum.

 

[king of pipes]

That is quite normal the boiler will run a high rate to heat the hot water and modulate down on the heating side and be quieter but there will always be boiler noise when it's operating . Kop

 

[panthro]

Yes, I understand boiler noise, but should it really be heard in the rooms below? I was assured by the plumber that noise would not be an issue if we put it in the loft.

 

[Chuck]

Oh so this can be set - do you think it will help with the hum? The water hum is much much louder than the heating hum.

The pump setting will only affect the 'heating hum' and only if it is the source of the noise, which may not be the case. I was was trying to cover all possible bases.

The 'normal' noise made by a typical combi fan is not silent, but nor is its pitch so low that it is difficult to record.

What's the boiler fixed to? Directly onto a nice solid wall or some other arrangement?

 

[panthro]

What's the boiler fixed to? Directly onto a nice solid wall or some other arrangement?

It's attached to the outside wall in the loft.

The 'normal' noise made by a typical combi fan is not silent, but nor is its pitch so low that it is difficult to record.

But is it normal to be heard in the rooms below the loft?

Thanks!

 

[Scott_D]

It's attached to the outside wall in the loft.



But is it normal to be heard in the rooms below the loft?

Thanks!

All that separates you and the boiler is 12.5mm thick plasterboard and some loft insulation.
Yes you are going to hear it unfortunately

 

[king of pipes]

Yes it will be amplified think about its a big room up there technically so will sound noisier I think you have been slightly misled , I personally will not fit a boiler in a loft although it is perfectly ok to so providing the regulations are followed, you could try adding extra insulation in the loft and adding insulation to the loft hatch or fitting a cupboard around the boiler . Kop

 

[panthro]

Thanks for all your responses, will fitting a cupboard around it have much effect?

 

[gmartine]

I don't think there is any blame to handed out here as new boilers are quiet (usually<45db) just not as quiet as you hoped and your plumber probably thought. You could add insulation to the loft, the pipes should be insulated but seeing how quiet you'd like it to be I'd retro fit a cabinet around the boiler. Buy something off the shelf and cut the back out and even insulate it to be sure allowing adequate access for servicing.

 

[Scott_D]

Any pictures?
is it straight onto block work, how are the pipes fixed to the walls/floor?

 

[king of pipes]

A insulated cupboard will help not only to help quieten the boiler but will keep it cleaner,

 

[panthro]

Any pictures?

I will try and take some tomorrow, but we don't have a ladder up there (I know it's required, but no one told me until I read it on here just recently).

A insulated cupboard will help not only to help quieten the boiler but will keep it cleaner,

Great advice, is it dangerous at all? What insulation?

Thanks everyone so far for your help!

 

[king of pipes]

Sheet armaflex I would recommend you will need clearance around the boiler so no not dangerous, more dangerous not having a loft ladder , boarded permanent walk way and rail , wired in lighting , smoke and co alarm ? I am guessing you will be missing a few of the above

 

[Brambles]

I don’t want to be the bearer or bad news, but my advice would be to get your access to the boiler in the loft sorted to meet regulations: Access ladder, handrails around the opening, properly boarded access to the boiler, working area around the boiler boarded, adequate lighting, ability to isolate the gas and electricity / control of the boiler without accessing the loft space. If you don’t, you run the risk of a manufacturer’s (OEM) engineer refusing to access the boiler if you need a warranty repair. It might sound very pedantic, but if you call and the engineer refuses on grounds of access, it is very difficult to get a return visit from the OEM.

With respect to noise - a properly constructed compartment may help - the problem is that once you have heard boiler noise (or any annoying noise) your brain seems to constantly search for it.

It reminds me of hotels that put fridges in bedrooms - the noise at 3am is really annoying!!