Noisy Heating System

[rabruce]

I am currently nearing the end of extending my house. The aging inefficiant Baxi heating boiler has been replaced with a Worcester 24 Ri and the existing system extended. There are TRVs on ALL radiators and no room stat. The hot water and heating systems are controlled by 2 zone valves. Beside the zone valves is a Myson ABV. A new Gundfoss pump was also installed.

The sytem was flushed, filled and started up last week by my plumber, who is now unfortunately for me, on holiday for 3 weeks. Since he started up the system we have been plaqued by loud squeeling noises form the pipework. This can be rectified briefly by turning the ABV however it returns when 1 or both of the zone valves change their status.

I spoke to the plumber briefly before he took off for sunnier climbs. He mentioned that it could be the hot water zone valve that was causing it, and we may have to replace it.

My questions are:

1. Can anyone give me a clue what could be wrong?

2. Apart from being very annoying, will this damage anything, such as my new boiler or pump?

I'd be grateful for any advice.

 

[diamondgas]

A picture tells a thousand words, :welcome: to the forum rabruce

Is the pump one of the new grunfoss alpha's? Heard a bit about them being troublesome and causing noise issues on new installs?

 

[rabruce]

A picture tells a thousand words, :welcome: to the forum rabruce

Is the pump one of the new grunfoss alpha's? Heard a bit about them being troublesome and causing noise issues on new installs?

No. The pump is a Grundfoss 15-60. It is new but also old, as it was bought over 11 years ago (Jan 2001) for my previous boiler but never fitted. It just sat in my garage, all boxed up on a shelf just in case it was required.

The plumber was happy enough to fit it.

PS Thanks for the welcome. :yes:

 

[diamondgas]

Okay

Does the noise sound like it's generated within the boiler or outside? I know you said pipework but eliminating the boiler eliminates heat related burner/heatexchanger possibles! Is the pump fitted vertically i.e. the big silver screw on the top?

 

[rabruce]

Just called home and the joiner has described the layout of the pump..and it seems to be sitting on its side i.e. horizontal.

PS the pump is set to No 2 in case this helps

 

[rabruce]

I should also have said that it sounds as the noise is being generated by the pipes and not the boiler.

 

[diamondgas]

If you turn the programmer off on heating and hot water so that nothing is being called for the boiler and pump should shut off eventually! It does sound like you may have a dodgy zone valve if what I've described doesn't occur

 

[rabruce]

The noise only starts after the system is hot i.e. It's been on for a few minutes (5-10 mins). When the programmer switches everything off then the pumps does run on and the noise sometimes comes back, sounding like a dog being strangled, with the noise eventually dying off shortly after the pump switched off. :dizzy2:

 

[DirksPlumbing]

The noise only starts after the system is hot i.e. It's been on for a few minutes (5-10 mins). When the programmer switches everything off then the pumps does run on and the noise sometimes comes back, sounding like a dog being strangled, with the noise eventually dying off shortly after the pump switched off. :dizzy2:

I would rather point to the ABV. First of all as the noise responds to altering the setting and second of all as it sounds like a spring loaded valve as the cause. Which indeed does not necessarily rule out the 2-port valves. I take nobody tried to install a check valve for some reasons?
Other reason making me think of a faulty ABV is the fact that it appears to be delayed which could go in conjunction with the TRVs closing. Is it Danfoss (RAS C2/D2) revolvers? They can make a noise like that as well if the revolver is in the wrong direction.
Is there occasional banging or knocking noises apart from the crackling expansion noises some do get?

As for the pump I am not sure if that was a saving as this pump will draw in excess of 100W even a standard 15/60 now only draws around 50W and a Class A pump 15/60 average around 20W.
Depending on your setup this might be at an average run time of 4h a day and 15p/kWh an electric bill for the pump of £22 a year as opposed to £4 on a A rated pump.
By latest when you need a new pump its a nobrainer as you get your money back in almost one year or even quicker.

And for the noises I found the A rated pumps normally curing noise problems pretty effective. Just need to be careful on Y/S plans with the pump/ABV setup. You normally need the constant pressure profile (the one that is marked for underfloor heating) in order to safely open the ABV if required.

Oh and welcome to the forum.

 

[AWheating]

i would agree its possibly the abv.

 

[rabruce]

The ABV is new. I think our old system just had a manual gate valve. I'll go home to think a bit more about it, and see if I can shine any further light on the matter, in between carrying out my joiner and painting work.

Thank you for your advice, and also on the use of the older pump. I may still change it, but it was lying around anyway. They TRVs are Danfos RAS but I'm unsure of the model.

I may come back tomorrow with further info.

 

[DirksPlumbing]

Well if it is RAS ones I would eliminate them as source for the noise first.
Put your heating on and check which side of the radiator heats up first.
Then set the revolver accordingly with the arrow pointing in the right direction.
Should not take long.

 

[rabruce]

I've looked online and I may have revolver model. I'll check tonight and if so do as you have mentioned above and get the arrow pointing in the right direction.

Last night the noise came back. I turned the ABV and the noise went away and shortly after that I could hear gurgling in the pipes (from near the pump). Can the noise be from an air blockage in the pipes?

 

[DirksPlumbing]

Last night the noise came back. I turned the ABV and the noise went away and shortly after that I could hear gurgling in the pipes (from near the pump). Can the noise be from an air blockage in the pipes?

Not very likely in my opinion. I would still point to the ABV. I think the easiest way to walk is step for step. Exclude potential problems that do not cost you anything at first.
There can be multiple problems. Remaining air on a freshly filled up system is nothing unexpected. Should the air problem get worse over time then you could have a problem with your heating water quality.
But this is most likely independent of your noise issue.