Radiator banging / clicking - possible reaction to F1 protector?

[TheGiantHogweed]

Hi.

We’ve had rather a lot of noise issues with our radiators since we had a new boiler installed. Our radiators other than 2 more recent ones are all over 30 years old.

When the boiler got installed in the middle of 2020, after the first few days, we had several loud airlocks each day. Probably up to 10 times in total until we got the plumbers round to sort it out. I can’t remember exactly what they did, but the air locks stopped occurring then. But what then was the case was that whenever the heating was on, the main radiator that must remain on all the time seemed to have a sound similar to a cold tap permanently running. That sound was amplified to the room above, unless the TRV on this radiator was either on 5 or totally off.

We got the plumbers back, and they then drained the system (not a blast out though) and added some Fernox F1 Protector.

This seemed to remove the issue I described with the sound like a tap was running, but introduced a whole load more.

The system clicks and bangs occur very regularly when the heating is on. It however is much more noticeable in my bedroom, but the noise is very similar in many other places in the house. It is not coming from the radiators, but they are what makes it more audible as upstairs all the pipes are under the floorboards. The F1 Protector I’m guessing caused some sort of chemical reaction. Every single day, loads of air / gas was generated and the radiators could be bled very frequently with more build up of whatever this was. The water was also very dark grey and smelt strong. We kept dealing with this throughout the winter ourselves and although the noise remained, the issue with the gas does seem to have gone now, probably because the radiators hadn’t been used this last summer.


Now, the clicking decreases when the heating is off at the boiler, but it still clicks or bangs randomly usually at least once an hour through the night. Sometimes it can be incredibly loud.



From what I’ve read, this now could be many things:


Boiler kettling – It seemed that F1 protector it supposed to help with this, but it seemed putting that in caused trapped air and other nasty reactions.

Expanding / shrinking pipes – This sounds like it could indeed be the case. As I can lift and move my radiator slightly and feel it rubbing in the hole in the floorboards, and I can almost create the identical sounds myself by doing this. However, the radiators and pipes have not changed since our boiler got replaced, so as that is the case, I can’t understand why this should be related. Our heating with our old boiler just bade a very quiet and consistent tinkling while on, and no noise when off.

Dirty pipes – While we had the F1 protector put in supposedly to clean the system, given the reaction it caused, it probably has made it worse. We don’t have air / gas in the system now and the water seems clean, but I obviously can’t tell what the pipes are like. I don’t believe it is related to the radiators now, as I can turn them off at both the TRV and other valve and the noise still occurs from the pipes.


As it is a new boiler with very old pipes and radiators, it is hard to know if a full system flush will solve this issue. I know that these radiators and pipes can be quiet, and nothing physically should have changed about them. Just likely to be something in them.



This clicking / banging has been irritating me so much that I’ve done rather a lot of recordings of it. So I can explain what it is better.



This first link below is actually from last year. This was during the day when I was at my desk. The microphone easily picks up me pressing a few buttons on my keyboard, but then it just sounds like a hard metal object hits the radiator hard. The radiator is nowhere close to my microphone, which just shows how loud it can be. This is a good example of what can occur in the night.

http://www.wetherby.me/wiki/pub/Sandbox/RandomImages/1_Radiator_Sound.mp3

This next clip is close up to the pipe when there was an obvious reaction of some sort. You can hear what sound like fragments rolling around in the pipes, spitting, gurgling and then this clicking and banging begins. The gurgling has long since stopped, but the banging and clicking remains.

http://www.wetherby.me/wiki/pub/Sandbox/RandomImages/11_Radiator_Sound_Close_Up.mp3

Number 6 was only from a few days ago when the boiler was on, but my radiator off. I’ve edited the recording and joined many of the sounds closer together. They sound similar, but can vary a lot regarding how far apart they are.

http://www.wetherby.me/wiki/pub/Sandbox/RandomImages/06-Left_Pipe_-_Morning_Noise.mp3

This is an awful lot of information, but I’m really stuck with what this is most likely to be, and what sort of people would know most about it and be able to sort it.







Many thanks.

 

[TheGiantHogweed]

Thanks for this.

I am unfortunately not very good at understanding instructions, so I could do with it breaking down a bit more if that is ok.

I have highlighted in your quote the parts I don't fully understand.

Was it making noises when (if) you tried it with both CH&HW off and the hot tap opened?.

I have looked back in this thread and tried to understand what you are referring to here, but unfortunately can't work it out.

This is the plug end you remove after opening the vent (screwdriver slot),

Unless I am missing something, it does seem that my radiators are different.

Here are some examples:

This above is our main radiator where the system can be bled (left picture), and the only one without a TRV. Though it doesn't look like it, the part above the copper pipe joining the radiator is only just over a year old. I think this initially having a poor fit was possibly related to the airlocks we were first experiencing, as this is what we had to adjust to stop them when they occurred. The other image above to the right is on this radiator where it is bled.
The two below are the two newer radiators.

And this is one that seems to look slightly different again, but is one of our very old radiators. Most of the radiators in the house have the same style valve as the top left picture.

you first (after first shutting valves at
both ends of rad) open the vent to ensure no pressure, then remove that blank end, open the vent a few more turns, syphon off a litre or so of water and pour in the F1 via a plastic funnel or whatever, close up the rad, reopen valves top up pressure if required, flash up the boiler and wait for the silence!!.

The rest of what you have said here, I may understand when I work out how to use the vent.

I assume you mean F2 here!

I also may as well know what type may be easiest for me to use. I've seen this style in a 265ml bottle elsewhere: Boiler Noise Silencer F2 Express 400ml - UK - https://fernox.com/product/boiler-noise-silencer-f2-express-400ml/

Seems more appropriate for the number of radiators.

Hopefully I will get to understand what you mean.


Many thanks.

 

[John.g]

CH is Central Heating. HW is Hot Water. Thought I suggested in some post (maybe on your other thread) or other to shut both (switches) of these off at the boiler front and open the same hot tap that was opened when you heard the boiler whistling noises, if no noise, at least you know the problem is with the boiler or/and system water.

I wouldn't advise removing any of those vents, might run into problems, don't know of any other easy method to add the F2.

 

[TheGiantHogweed]

CH is Central Heating. HW is Hot Water.

Thanks. I think it is more likely to be coincidence, but maybe it is related to hot water and not just the central heating. As this morning had pretty much the same pattern as the image I showed you. Noise when it first comes on at 06:00, and then went quiet until later on, which when I think about it is often when our shower is used. I haven't noticed this pattern in the evening though, which is why I'm not so certain. Our shower is just gravity fed from a cold water tank and heated up by the boiler (if i understand correctly)

Thought I suggested in some post (maybe on your other thread) or other to shut both (switches) of these off at the boiler front and open the same hot tap that was opened when you heard the boiler whistling noises, if no noise, at least you know the problem is with the boiler or/and system water.

I haven't heard any noise from the boiler itself that sounds at all worrying. The airlocks when we had them was extreme noise and vibration from the pipes near the TRVs, but this soon got sorted. The rest of the noise is just these clicks and bangs now.

It is entirely possible that I have filtered some things out that you have said, or misunderstood them due to my poor memory though! If the hot water system for the taps and shower could be related, them that admittedly isn't something I have yet tried turning off and running cold, though I don't know how I would do that exactly.

I wouldn't advise removing any of those vents, might run into problems, don't know of any other easy method to add the F2.

Thanks for making this clear, I'm not surprised I didn't understand. At least I know that if I want to try this, i will have to try and contact a suitable plumber. We've just put this off as each time any have come, the issues seem to have got worse. At least we know that things change each time, so hopefully it will go in the right direction next time.

Just not sure if the call out cost for adding the F2 would almost make it worth finding someone that can do a power flush, though I know little about the rough price for what this could be.





This is likely unrelated, but I've found an old picture that my dad took of how the plumbers originally installed our pump, which wasn't in the position the manual stated it should be:

 

[John.g]

I think I've mixed up threads and thought you had a combi so obviously cant carry out the "cold water" flow test.
May have asked this previously the boiler might display the temperature on its front, if so see what its showing, if > 65C reduce it to 62/63C and see if any difference.

 

[TheGiantHogweed]

I will have repeated myself enough in this thread, so don't worry that you have. Yes, you did mention this earlier and I have changed it. It was originally installed and put to 69 degrees. We now have it at 62 / 63 which we have had it at for some time now. This is the same temperature we had our old boiler at.

My next option then is probably to find someone who can add in the F2 protector correctly, and would probably be ideal if they would also be able to do the appropriate power flush should the first option fail. Or may even be better to avoid the cost for both and do a full power flush. But could do with someone working out what it could possibly be. I will look around this forum. I'm not yet sure on how or if you can ask for jobs here and if there are any limitations.

Many thanks for your help.

 

[John.g]

I feel that you will have to grasp the nettle and get a full power flush done professionally.

 

[TheGiantHogweed]

Well, no luck.

Had the radiators power flushed. The water was confirmed to be rather brown and dirty. So I should still accept that it will have done the system good, but these bangs and clicks are still there.

As every different company / plumber or any place will be like, everyone tells you different things. They said the speed of the pump should never have been touched and left on what it was when it got installed. They put it back to speed 3 which I still think is seriously overkill for a house this size with 7 radiators. The noise this pump makes is just too much on this speed. You can hear the hissing from it at ever radiator in the house. Basically making it sound like the boiler is in every room. I will try and get hold of them regarding the other sounds still being there, but despite what they say, I still plan to switch it back to speed 1, as the heating was just as effective at keeping the house warm with it set to this over the last year.


It is still really puzzling as to what this is. I would not be against it being related to pipe movement with heat expansion and shrinking it it wasn't for the fact that this suddenly started the same day that the system was bled with f1 protector them added. The pipes occasionally tinkled before, but they didn't bang and click all over the house. There has never since been a heating cycle without this happening. It is still almost exactly the same as the picture I last uploaded. There seemed to be very little noise when the plumber first tested it for half an hour when the boiler was set to the highest temperature possible. But when it was reduced to eco (69 degrees), it then started.

I can only guess that something really odd happened relating to the method they filled up the system when they added the F1 protector. This noise is not from the radiators, they are just acting as amplifiers. It is from the pipework. When downstairs, i hear bangs, clicks and pops all over the place. being very sensitive to directions, it has basically allowed me to learn where all the pipes must be, that I never knew before. Why would they be making these clicks all over, at different random stages when they didn't do so before?

Having spent £800+ on a power flush that has failed to get rid of this, as well as attempting different boiler temperatures, pump speeds and all sorts, I am baffled as to what this can be. I accept that heating is nearly impossible to get to make no noise at all. but me being as sensitive as I am, this disrupts my sleep and even focusing on listening to the TV. Although the clicks are obviously not always happening every second, they really are not quiet at all. It just sounds like someone tapping the pipes with a screw driver.

The picture of the audio is an hour of the heating in the evening. You can see just after 45 minutes, it switches off which gets rid of the pump noise, but then the clicks and bangs go crazy for a while. This was not the case until after the power flush, but may be related to the excessive pump speed. The audio attachment is the stage where the pump switches off. Where this is recorded is on the other side of the house to the pump.

I've also just found a video from ages ago before the system got bled and the F1 protector got added. This was well after we got our new boiler and pump. The heating instead sounded like the video shows unless all the TRVs were on full. Whenever they were reduced, it made this main radiator sound like a cold tap was running. This sound could be heard in my bedroom. This infact would still be far better than what is now the case with intermittent bangs. Something strange caused this, but I don't know what.

Sorry for all this info, but just trying to list everything I've tried to make it as clear as possible. I myself am desperate to reduce this noise as it is incredible disruptive.

 

[Ric2013]

Given the chaotic (but sadly not uncommon) state of the floor void: pipework, electrics, and general debris typical of any house built without care or modified on several occasions during its life, it doesn't surprise me particularly to hear clicks and noises. I do wonder whether the noise may have come into play when the boiler or pump was replaced and whether some of the existing pipes may have been moved or twisted very slightly and whether this may have led to them grip/slipping against adjacent surfaces during expansion or contraction phases while, perhaps, the air noise was masking these quieter sounds. Indeed it is incredibly hard to work on pipework that is not fully supported without moving it al least a little. That said, I may be going up a dead end in that I find it hard to entertain the idea that the F1 was a cause of the noise, and I may be wrong.

I do have a hunch (no more than that), that someone has fiddled with the balancing of the system. The balancing may now be out or it may have been out previously and is now correct (but is now making a noise it didn't used to due to the return pipes being warmer or cooler than they were in the past).

As every different company / plumber or any place will be like, everyone tells you different things. They said the speed of the pump should never have been touched and left on what it was when it got installed. They put it back to speed 3 which I still think is seriously overkill for a house this size with 7 radiators. The noise this pump makes is just too much on this speed. You can hear the hissing from it at ever radiator in the house. Basically making it sound like the boiler is in every room. I will try and get hold of them regarding the other sounds still being there, but despite what they say, I still plan to switch it back to speed 1, as the heating was just as effective at keeping the house warm with it set to this over the last year.

Essentially, the test for correct pump speed on a modern boiler is that, once the system is warm through and with all radiator manual on/off valves or TRVs fully open, the water leaves the radiators at a temperature no more than 20°C cooler than it went into the same radiator. This would be measured at each radiator; the flow though each radiator can be adjusted (called 'balancing the system') but the pump speed would be set to be fast enough for the radiator that seems to be least easy to supply sufficient water to.

In the old days, the old boilers were coupled to system that would give return water 20°F or 11°C cooler than the flow when the boiler flow was at maximum (around 82°C), but that was largely arbitrary and much to do with the need to avoid thermal stresses to the boilers of the day. This is relevant to you as your system would largely have been designed to work under these conditions: older radiators may not give enough heat on a 20°C drop, so your drop may need to be set at less than this.

At a guess, I would imagine speed 1 would be sufficient for 7 radiators, especially radiators of that age which are unlikely to require a huge amount of flow.

I can only guess that something really odd happened relating to the method they filled up the system when they added the F1 protector.

Or some small change that took place at the same time and they didn't even think to mention (I'm clutching at straws here!).

The picture of the audio is an hour of the heating in the evening. You can see just after 45 minutes, it switches off which gets rid of the pump noise, but then the clicks and bangs go crazy for a while. This was not the case until after the power flush, but may be related to the excessive pump speed. The audio attachment is the stage where the pump switches off. Where this is recorded is on the other side of the house to the pump.

Ticking noise certainly sounds like thermal expansion to me, and the plethora of ticking after the pump switches off would suggest thermal contraction.

I've also just found a video from ages ago before the system got bled and the F1 protector got added. This was well after we got our new boiler and pump. The heating instead sounded like the video shows unless all the TRVs were on full. Whenever they were reduced, it made this main radiator sound like a cold tap was running. This sound could be heard in my bedroom. This infact would still be far better than what is now the case with intermittent bangs. Something strange caused this, but I don't know what.

That running tap noise in the old video with partially open valves is the result of the water, pressured by the pump, squeezing through the restriction created by a partially open valve. It would be undesirable in a properly designed system, but can be unavoidable if modifications to an elderly system (such as fitting higher output radiators) means that the only way to shove sufficient water through some parts of the system without creating excessive flow in other parts is to up the pump speed. In such a case, the pump may need to run at top speed with some of the circuits heavily throttled back. Ideally, the radiator with the most restrictive (longest, usually) pipe run would have its valves fully open and the pump would be set just right to feed that circuit, with the rest of the radiators throttled down and you'd hope the pump would not then need to run so hard as to create this kind of noise.

From your description, I would suggest that what is happening is that the pump is set to a fixed speed (as all old pumps did - modern pumps can (if set to a proprtional pressure setting) vary their speed to give more flow when required and less flow when not required, but this setting tends to provide less pressure than the fixed-speed setting, so does not always work on a legacy system that might simply require more pressure). The fixed speed means the pressure increases when there is little flow through the other radiators, so, having nowhere else to go, it's getting shoved through your only non-TRVd radiator.

Sorry for all this info, but just trying to list everything I've tried to make it as clear as possible. I myself am desperate to reduce this noise as it is incredible disruptive.

I get it. Noise is, actually, one of the (several) reasons I switch my heating off altogether at night. Sometimes theory and practice don't quite go together and there are factors we cannot see. Which can sometimes be more annoying than the symptoms themselves!

 

[TheGiantHogweed]

Right, going over a few more things.

Now I think about it, I do remember that when the plumber had completed the power flush, they tested the system by leaving it running for about 40 minutes while they just waited outside in their van, which I think was quite nice of them as they wanted to make sure it made no noise. This test however was with the boiler set to it's maximum temperature, which obviously is overkill.

Thinking about what Chuck mentioned on the first page, maybe this new boiler does cycle on and off when set to a realistic temperature for the heating (69 degrees). So maybe this is the reason why it can sometimes be quiet for nearly 20 minutes while the heating is on, but maybe when it gets to a certain temperature, it switches off and makes the pipes contract and bang for ages. At this rate, I don't really care if I have to use a less efficient way - I will accept to have to have more input in my parents heating bills given how much I'm suffering with this noise. If there was any way of balancing the system so that when the heating is on, it doesn't constantly need to change the pressure in the pipes. I'm guessing our old boiler did things differently.

The main confusion is just that this dramatic change did occur when the system was bled and refilled with F1 protector. It may well not be the F1 protector, I just know that went in. Maybe it could be related to what happened for about a month after this? More or less instantly when they got refilled in October 2020 with F1 protector, there was loads of air / gas beign generated with no leaks anywhere. Daily, I would bleed the radiators and get a load of black dirt and froth and didn't get to just water until the radiators had been bled for over a minute. This seemed to calm down later into winter and whatever muck was in there had settled / hardened in the pipes over summer when the heating was never used.

Now, is it possible that this reaction was that strong that even a power flush has failed to clean the pipes? Long term damage or something?

The heating still functions fine, although there still is regularly small amounts of air in the radiators when bled. The water is very clean now though. But the noise is now worse than it was just before the power flush.

The only improvement I can think of myself is putting the pump back to speed 1. I will wait until after the plumbers come back as I don't think they agree, but the specific pump noise is loud enough that even my parents are wondering why that makes so much noise. Although in reality, it is quieter than the clicks, just permanent when the heating is active.

Any other suggestions for things I could try will be worth knowing. It may involve ripping up floorboards at some stage, but that should be left until I'm out of other possibilities, as I still don't get what exactly it could be that so suddenly started this banging and clicking in the October before last!

 

[TheGiantHogweed]

Had the plumbers come round again after the power flush had been done, but as i thought may be the case, they were unable to do anything further.

The system water is now perfectly clear, so i still think the flush was worth it. The pump got changed back to speed one, which is certainly quieter regarding the noise of the pump. It however hasn't got rid of this pattern of the heating cycle which still seems pretty much identical to the picture I shared further up the page. It seems that if the boiler and thermostat are at the highest temperature possible, there is virtually none of this noise. It isn't like the radiators got baking hot like this with our old boiler, so it must just be related to the system working differently when at the temperature it should be. I will try turning it back to around 63 degrees.

One thing the latest plumber told me is that the noise more likely started in one location, and travels to others as the system is all connected. I can understand that point of view, but I'm not convinced. There are different noises at different areas of the pipework under the floorboards as the frequency and volume is entirely different, and they occur at different stages. And when downstairs, I can clearly hear the noises coming from all over the place at different stages. I've basically learned the path of the pipes that I never knew before based on where the noise is coming from. I find this unbearable unless whatever I'm doing is consistently that bit louder than the clicks. It can even distract me while having conversations due to how sensitive I am.

If I knew one area started it, and that would stop it, floorboards coming up would not be as much of an issue. But it is clicking and banging everywhere...

The only pipes that I feel have any reason to have moved in the slightest when the boiler and hot water cylinder installation got done were above the boiler in the bathroom, and the bedroom with the hot water cylinder. Also where they first bled the system which was on the only non TRV radiator, but that radiator and the pipes under it don't really seem to make much noise. My bedroom is on the other side of the house to the hot water tank and boiler and the pipes can't have been sifted, other than by natural expansion and contraction. But the noise is awful here, and most other places.

I'm really stuck with where to look under the floorboards first.

 

[Ric2013]

I see the point about increased possibility of cycling (ON/OFFing) of the boiler with a reduced flow temperature, but can't see why that would start separately from the boiler change. Obviously if the old boiler was underpowered, it would run flat out to try to get the temperature up whereas if the new boiler is oversized, it will have to cycle to avoid overheating. I suppose increasing the boiler setpoint will increase the required heat output, but ultimately the room will reach the set temperature and then the system will cycle instead. May be less in terms of cycling, but probably won't eliminate it.

Can you remind us what make and model boiler you have please?

 

[John.g]

Our new boiler is the ideal LOGIC HEAT R18

 

[TheGiantHogweed]

I see the point about increased possibility of cycling (ON/OFFing) of the boiler with a reduced flow temperature, but can't see why that would start separately from the boiler change. Obviously if the old boiler was underpowered, it would run flat out to try to get the temperature up whereas if the new boiler is oversized, it will have to cycle to avoid overheating. I suppose increasing the boiler setpoint will increase the required heat output, but ultimately the room will reach the set temperature and then the system will cycle instead. May be less in terms of cycling, but probably won't eliminate it.

Can you remind us what make and model boiler you have please?

Ugh I don't understand the issues I'm getting with this forum. Both on my PC and tablet, a few seconds after it loads everywhere has a grey filter making everything so hard to read. It is like something is blocking it.
Anyhow, I can just about read it and read it no problem when i log out!

This is the boiler:
LOGIC HEAT H18

 

[ShaunCorbs]

@Lou

 

[Lou]

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