Singing boiler

[Martino]

Hi Folks.
Over the last few weeks my boiler has got a bit noisy when the heating is on but not when the hot water is on and not when both heating and hot water are on together. It's a 20 year old Ideal Elan. System powerflushed and balanced 18 months ago. Boiler had new circuit board and fan assembly within last couple of years. New pump and 3 position valve also within last couple of years.
So.... when heating has been on perhaps 30/40 minutes it starts to sing a bit. I can only describe it as a deep whistle. Gets worse (noisier) as it gets hotter but does seem to settle down at a "highest" volume after a while. As we generally only have the heating on for an hour or so at a time I don't know if it will continue to get any louder.
In the room above the boiler the radiator has a thermostatic valve and I discovered that if I turn that up a bit it relieves the noise for a while although it will eventually start up again. To me as a layman that suggests that the noise is some kind of overheat thing and by opening the valve up a bit I'm giving the system a chance to dissipate a little bit of that heat into the radiator that I've just turned up. Probably/possibly a stupid theory but you never know.

Any thoughts folks? What can I do to stop this noise, which can be heard throughout the house and is starting to get a bit annoying. Obviously I can't keep notching the the thermostatic valve up....

Thanks.
Martino

 

[cross thread]

try adding silences it may work,sounds as the heat exchanger is scaling up.no suprise on a elan that old,also check the system by pass is set to give a good flow through the boiler

 

[Boilerman2]

If the above does not work, sign it up for the next series of Britain's Got Talent!!

(I'd vote for a Singing boiler every time

 

[JohnD]

...In the room above the boiler the radiator has a thermostatic valve and I discovered that if I turn that up a bit it relieves the noise for a while although it will eventually start up again. ...

rather than a talented boiler, this suggests to me that the TRV, as it approaches its preset temperature, and is closing, is giving a very narrow aperture that the water is squirting round driven by the circulating pump. This causes a whistle. Have a look to see if the TRV has a flow direction arrow cast into the body; and if the water is flowing in this direction.

In order of ease and cheapness, your remedies are:

-reduce the flow through that radiator by turning down the lockshield at the other end of the rad so it is only open a fraction of a turn, but just enough to let water flow through that rad

-if the TRV is on the wrong end, take it off and put it on the right end

-buy a new bi-directional TRV

If you post a pic of the TRV, or at least tell us what brand and model names it bears, this will help.

If you have a system with a HW cylinder, you can turn the pump to the lowest speed that still gets the rads hot. I am not a pro but I have been told not to do this with a combi.

 

[joe-90]

You could call it Susan Boyle-r.

 

[mysteryman]

It seems that you need a bypass on the heating circuit, or to remove the TRV from one radiator, preferably the hall rad. Then there will always be some circulation. You could have a room thermostat in that area for better overall control.

 

[Martino]

Thanks guys. I'll look at the RTV and how the lockshield is set. In theory as the rad is one of the first in the system and the system was balanced when it was powerflushed 18 months ago it should be OK - but you never know. The furthest rad in the system isn't getting as hot as it used to (but is hotter than it was prior to flush/balance) which suggests that the system can "unbalance itself" doesn't it?

My son, whose bedroom the rad is in, is a bit of a cold freak so doesn't often have the RTV turned up. Maybe it's sticking through lack of use? I'll make sure it is opened/closed frequently to see if that loosens anything up or does anything.

I don't have RTVs on all rads so there is always some circulation.

There is a bypass in the airing cupboard - as in some pipework that seems to come off off a pipe and straight back onto it with nothing in between except a gate valve - can't see what purpose it serves. But I checked and it is open... The pipe it comes off and on again comes up through the floor to the pump so I'm assuming is from the boiler.

Don't you just love all this laymans thought process?

 

[Martino]

Oops. RTV? I meant TRV of course. Dyslexic? Me. Nerev.

 

[expertgasman]

[quote="Boilerman2";p="1803486"]If the above does not work, sign it up for the next series of Britain's Got Talent!!

Is that a plug for BG Talent

 

[Agile]

A common cause of singing with a boiler that has not been properly serviced is that the power input has drifted too high.

A registered engineer needs to check what its set at. In many cases even if its set at the recommended figure it can be lowered to reduce the effect of the kettling.

The flow rate should also be checked by measuring the temperature differential across the flow and return pipes. On that boiler it should be about 11°C. The pump speed setting should usually be on "2" or higher.

If that does not completely cure the problem on its own then it can be treated with a chemical in the water. Sentinel X200 is the usual choice. Its very easy to use an can be left in the system.

Its best to close off the largest rads and add it in the F&E tank and have the boiler run for a few hours before diluting the concentration by opening the other rads.

Tony

 

[JohnD]

even though?

...In the room above the boiler the radiator has a thermostatic valve and I discovered that if I turn that up a bit it relieves the noise for a while although it will eventually start up again. ...

 

[Agile]

Of course my suggestions to remedy your boiler "singing" were based on YOUR own statement that its your boiler producing the noise.

Reading the thread again and your comments about the TRVs then its quite possible or even probable that its not your boiler singing but just one or more TRVs closing when you have no bypass and the puump is on setting "3".

Another aspect is what type of TRVs are fitted and if they are fitted on the flow ( hot ) end or the return end of the radiator.

To correctly diagnose remotely we need totally full information on your system and how its operating.

Tony

 

[Gasman77]

Ha Ha wrong again Tony! When will you learn that every fault is not caused by someone failing to do their job properly?

 

[PEDANTICVINDICTIVEMAN]

I know what Clint Eastwood would say to the TRV, "are you gonna heat that radiator, or whistle Dixie"

 

[gavinda]

I dont know what brand the british gas trv's are, but i know that if they are knocked too far onto the radiator tail when fitting (when the tail is longer than previous valve) that it will cause a whistling noise.