Boiler noise - HELP please.

3 Feb 2006
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United Kingdom
Good morning all.
My central heating system is 5 years old. It is standard gas fired pumped open vented system. Boiler is a glowworm 60f economy plus ff.
The problem is the noise from the boiler when the burners are heating the exchanger.
The noise is gone as soon as the fllame drops out on temp.

System has been treated with fernox restorer. Pump is new. Water feed is fine. All rads etc heat quickly & have no air in them during normal running.

Noise can be made to go or reduce by running pump on speed 3 & turning boiler stat down to about 1/4.
But noise increases as you drop pump speed down.
Have I got a nasty scale build up in heat exchanger? Advice please
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Yes sounds like classic kettling. A few people on here swear by boiler silencer but to me this masks a problem and doesnt cure it. Pesonally id replace the heat exchanger and get the system water looked into.
I would love to just get the heat exchanger replaced. But those nice service people want £225 +VAT to come out to look. This covers all parts except guess what? HEAT EXCHANGER. When I told the nice lady that I am 99.9% sure thats the noisy bit she eventually got me a price for it ----£389 + VAT. The cheapest I can find on line is £250 + VAT. I know everything costs these days, but this seems excessive in the extreme!
As I can get a Super dooper condensing boiler for £599 & Just pay for the install I will go that way rather than pay more to fix the same old boiler.
Fernox DS40 just gone in system (did not think it was worth wasing time with restorers etc an more). I will run it for the max 7 day period. Hope the bad things Ive read about it wont happen to my system....
elsmirkio said:
Fernox DS40 just gone in system (did not think it was worth wasing time with restorers etc an more). I will run it for the max 7 day period. Hope the bad things Ive read about it wont happen to my system....

Brave move!
Personally I love the stuff but I get the feeling other plumbers dont share my views.

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Its fine replacing the whole boiler but whats stoping the new boiler going noisy in 5 years time?? Id be getting the system properly flushed which is as least a days job to do properly.
If this DS40 treatment does the trick, I will "completely" flush the system & make sure the water is treated to the best of its ability.
If I change the whole boiler, I will do the same & keep on top of it. I am just astounded at the repair prices compared to brand new, & besides the boiler operates fine & the system does all its meant to, its just this poxy resonance & having to run the pump on 3 to make the noise tollarable.
Quick question for you guys.....
I have been told a "hot flush" is a good idea?
Alledgedly this entails opening one of the lowest drain offs, then running the system whilst checking the make up of the header matches the outflow.
Sounds rational to me.... Any views?
UPDATE ---- DS40 (now decided its good stuff!) been in system 4hrs now. I have just been able to drop the pump speed to number 2 without a tractor with no big ends sound effect.
Looks like its working its magic. At this rate I will be back on speed 1 tomorow FINGERS CROSSED.
I've posted a thread on almost exactly the same problem with the same boiler. I've just put Sentinel X200 in to see if they fixes it.

If that doesn't do the trick, can you use DS40 in the same system that has X100 (about 3 years old) and X200 in it, or does it need a flush? I'd rather keep this quick and cheap as I've just exchanged on selling this house! :)

The stuff is good but it will find leaks on a poor system!

Remeber to flush it all out. This needs doing properly through every drain point with certain parts of the chs shut off.

Dont be tempted to drain it out before your 7 days are up even if you can see small gains so quickly.

Best of luck and may you be pin hole free for the next week. Sleep with one open eh.

Its quite spooky that we had identical boiler problems.
DS40 has not eaten through anything yet, but the improvement is incrediable. Just dropped pump down to speed 1 & all is quiet.
Amount of gassing up is amazing--- I suppose its chemical reaction from it eating limescale. But a nighlty bleed is no hardship. It is tempting to remove it before the 7 days, but I will be good & patient.
I looked at all the products & even put 1 & half bottles of fernox heavy duty restorer in, but my system was not blocked up or sludged.
Thinking about it the heat exchanger has so much opportunity for having limescale, it being a tube type rather than a cast iron one. My fault completely, during ongoing building works, I ran the system without any additives for over a year. We live in a very hard water area.
ive used ds 40 a lot & had no redress. if your system has weak spots it finds ,then they were weak spots.not the fault of the ds 40.if ya gona have a weak spot go u might as wel be prepared for it as it happen when your away. as long as you follow the instuctions with the neutraliser & flush well over the top I swear bye it. do leave in the maximum though cos the scale can return even with good inhibiter in. it may of soon removed the smallest bore blockage in the heat exchanger but u cant see how much is still in there thats not causing any noise.Belts & braces & it wont hav ur pants down!

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