Loud kettling noise from boiler

udip

Hi there,

I hope someone out there helps me out.

We have a Potterton boiler (4yrs old) installed by the builders when we moved into our house. All these years we have had no problem with it. Except last november(2009) we got our attic converted and had construction work carried out at home and since then it has been acting up with a series of problems starting from the boiler not heating up, broken thermostatic valve to loud kettling noise when the heating starts up.

At the moment the boiler is working fine except that it is making very loud scary kettling noise when it starts up (for 2-3 mins) and then the noise stops. We had this boiler serviced couple of months ago by Bord Gais and the guy told us we need to power-flush the system seeing that there was some debris in the filter when he had a check. Since then we got the system power-flushed which cost us 400 euros and looks like that wasn't really the problem since the noise is still the same.

One thing I would like to add is when the construction work was going on there was a sharp increase in the water temp for about a month or two....the plumber guy could have cranked up the temp while carrying out his work (i would say that he did goof up a few other things in the house as well)...which leads me to believe that could have caused some damaged to one of the parts inside the boiler. I am really frustrated cause we have spent over 500 euros and haven't found a solution yet...all this work comes for a price.

I don't mind paying the money if there was a guarantee the system could be fixed. The next thing that has been suggested to us is to replace the heat exchnager which would cost another 400 euros (approx).

Please help....would really appreciate some advice here from experienced boiler experts as to what the problem could be.

Thanks in advance.
udip

JohnnieK

Don't go down the heat exchanger route yet (and it shouldn't cost €400 euro either) It dose'nt sound too bad if the noise goes after a couple of mins. Did the guy who power flushed the system put an inhibitor into it when he was finished? There should be a sticker on the boiler if he did. If not one should be put into it. Another additive you can try is a noise reducer.

Also the boiler might not be vented properly and have trapped air in it, and the fact that the noise goes after a couple of mins.

items

Sounds like your system has built up a great deal of iron oxide (internal corrosion). As above before going into great expense by replacing parts best be sure system has been cleaned and flushed properly along with the addition of inhibitor during system refill.

The cleaning / flushing process is complicated enough, the top notch heating engineers will take a sample of heating system water and add cleaning chemicals required at the correct dose to break down sludge enough to fully flush out system.

Its possible you've had some kind of an attempt of a system clean / flush which was unsuccessful.

udip

JohnnieK wrote: »

Don't go down the heat exchanger route yet (and it shouldn't cost €400 euro either) It dose'nt sound too bad if the noise goes after a couple of mins. Did the guy who power flushed the system put an inhibitor into it when he was finished? There should be a sticker on the boiler if he did. If not one should be put into it. Another additive you can try is a noise reducer.

Also the boiler might not be vented properly and have trapped air in it, and the fact that the noise goes after a couple of mins.

Thank you so much for your reply.
Yes, the guy who power flushed the system did add de-scaler and also an inhibitor to it when he was done. A noise reducer could be something that we might have to try out. Btw, the guy who did the power-flushing also did bleed all the rads in the house just to make sure there was no trapped air. Did you mean the same when you said the boiler might not be vented properly?? I could try and bleed the rads again....just to be sure.

GopErthike

Which Potterton is it? If it's a Potterton system, and he has already cleaned the filter well then you need to try a new thermister. A faulty thermister will cause a kettling noise by letting the gas valve ramp-up higher than required, therefore heating the water too quickly. They're not expensive, but again he must be RGI to do it.

JohnnieK

udip wrote: »

I could try and bleed the rads again....just to be sure.

Bleeding the rads will do nothing. System boilers have no vent to vent air when filling. it has to be physically removed from the boiler. This will cause the boiler to be noisy when starting and then you would hear it every now and again when the boiler is running. Also monitor the pressure gauge on the boiler if it fluctuates when you hear the noise it's air.

Another way to know is to empty your kettle and turn is on briefly if the boiler noise resembles this then it's ketteling. If this is the case Try the noise reducer. If this dose not work get an RGI to look at it. Make sure he services and repairs boilers all the time.

GopErthike

Hey Udip, any joy with this? Just curious.

Kingpowerflush

Hello Udip.

When you read these posts did you get the right answer to your problem?

If not, can I ask you a few questions of my own?

1 Did the noise start before or after the boiler service?

2 Is the system sealed with no header tanks (system boiler) ? If it is then check the pressure. Between 0.9 and 1.3 bar is good for most system boilers but check the user manual and stick with that.

3. Did this noise start after the powerflush was done?

4 Do any of the radiators have a camel-shaped cold patch at the bottom?

fours years after a proper clean, they shouldn't have (except in unusual, but not impossible, circumstances). but if they do then you might need a real powerflush done.

5 Do you get a guarantee? We do quite a few powerflushing/problem solving jobs each week. And here, in Wiltshire (UK) British Gas claim to give a lifetime guarantee with each job. (Which is arguable - as anyone booked to do ex-Bg customer powerflushes could confirm)

If you were guaranteed why not make a claim against them? If you were told that you needed one then they should have made sure it did the job. Or negotiate an alternative with you at no extra cost.

Incidentally, 400 euros is still just about less than 400 pounds, isn't it? I've no idea but I bloody hope so. And really, if t he problem is solved for you for good by someone who truly knows what they are doing, it's not a huge amount. Really. For that peace of mind? Not to mention the lack of sex from the missus stressing about being cold and all.

If the gas man refuses to face up make merry hell with them. Squeaky wheels get oiled first. Excluding your good lady of course.

6 Have you spoken to Potterton about what's going on? No doubt you have but, if not,

Potterton Myson (Irl) Limited
Unit 7 Whitestown Business Park
Tallaght Dublin 24 Ireland
Email : post@potterton-myson.ie
Tel +353 (01) 459 0870
Fax +353 (01) 459 0880


7 Just a thought, but did the builders cover any unsealed pipework when the work was going on?

My post has gone into bold type and I can't turn it off.

8 that's not a question. It's late and question time is on any minute.

If you are still looking for an answer and would like some un-biased advice, I promise that I am either too busy/too far away/too expensive to blow smoke up your ass.

Best wishes (blimey where'd the bold type go?)


kbo

Ian