Intermittent problem with noises in pipes

Guys & Gals,
Firstly if you're tired of hearing about this please forgive me but I need some sound advice. This problem is not constant. A while ago I noticed what I can only describe as 'whooshing'noises. When the boiler (A 4 yr old Potterton Kingfisher MFCF60) comes on in the morning it ignites and starts the cycle of warming the water for awhile and then switches down. Starts ups and a few seconds later the whooshing noise starts, lasts for a few seconds then goes. 10 mins or so later the boiler kicks in again to heat the water, switches down - nothing - beautiful silence. Next start up and close down, whooshing again. Started getting more often, got so bad I thought the pipes were going to burst it was so loud. It also shut the boiler down (the red light came on). Called Corgi man. He changed pump. Worked fine for a week then started making the noise again. Corgi man came back. Connected what I think he said was an air valve on one of the pipes to help release air. Worked fine for a few days then started making the noise again. He checked cold water tank. Checked little white temperature box on immersion heater. He went away. Noise has started up again and got to the point of shutting the boiler down. He has spent the last weeks avoiding coming back to me and has said he really doesn't know what it is because it has never made the noise when he has been at the house checking it so it is difficult to discern where it is coming from. The other point that may be worth mentioning is that when I switched the heating on in the last cold spell that seemed to stop it happening for awhile as well. However, one week later and it now makes the noise when the boiler is working for the central heating. Am I looking at having to get someone in to give it a powerflush or is it an air problem, boiler problem or god forbid, BOTH!!!! (Also when it got so bad that it shut the boiler down the poor old pump in the cupboard started making the most horrid noises as well (as if it was trying to push something through but could'nt.) Sorry to rabbit on but I am a 50 year old woman with absolutely no idea of what is going on. Any advice warmly welcomed (even if it is to get the Gas Board in!)

You say the boiler is 4 years old? How old is the system you have and what size. It maybe pump/cold feed/open vent configuration, hydrogen problems, is it fully pumped? etc, try and post as much more info you can, the more help you can give.

Hi Gas2 air,
Many thanks for replying so quickly. Firstly, where will I find the information on what size it is and when you say system, do you mean all the pipework and stuff? The only information I have to hand is the installation and commissioning leaflet. Will this help?
The one thing I do know is that the system was changed to ' fully pumped'. As far as I know the pipework running round the house was installed with the first central heating system in '73. I had to have it changed when I moved in 2002.

Ok, how many radiators do you have? What size is your house.

Now, have a look at your boiler, how many pipes and relatively what size are they/age coming out of it? Is there a pump there? IE pump noise from it? If not go to your airing cupboard or wherever the hot water cylinder is kept. Ok, tell us what you find in there, pump? valve of any kind(s). Can you have heating on indepenantley of hot water via the programmer/timeswitch?


Is there a red headed/brass valve on the copper pipework near the cylinder and low down Hot Water Balancing Valve?

If you can't find any of these then they either in the loft, boxed in or under the floorboards.

Take a pic of what you see if u can, but my honest opinion is no balancing valve on the Hot Water return or cold feed/open vent config, causing noise/hydrogen/air/eventually sludge.

Excellent reply .....but you don`t necesarily need a corgi to diagnose/fix problems with the system .......you may find a non-corgi plumber/heating installer is a *little* cheaper .......but they should do no more to the boiler than turn it on/off and turn up the thermostat..particularly one like me who can`t even smell the gas ..Alternatively, armed with "Caveat Emptor" contact British Gas

Here goes sweetie,
1. 11 rads.
2. 3 bed semi.
3. The boiler is freestanding in a cupboard on the landing. As I look at it down the back, on the left hand side: 1 pipe at top has 'flow' written underneath it. This pipe goes off to the right and goes through wall into the airing cupboard next door, also on the left hand side, lower down is another pipe which ends rather abruptly has 'gravity return' written on it. There are two other pipes coming out of the floor feeding into the boiler at the bottom. I can only assume that the pipes were put in at the same time as the boiler.
4. The pump is in the airing cupboard and just says Grundfos with lots of numbers on it.
5. Yes, the heating and water can be run independently (however, noise is most noticeable when it's just the hot water being heated.)
6. Yes there is a red topped brass fixture on the pipe leading out of the immersion heater which then leads on to the pipe where the pump is. This is the one he fiddled with each time he came after fitting it. He also did something with the pump each time he came as well.
7. If there is a balancing valve on show I'm not sure where it is. There is another valve type thing down at the bottom of the immersion heater, which has an old-fashioned looking red handle on it. I'm afraid I can't take any pictures sweetie, I don't have a camera. One thing I really would like some reassurance on, is it, or could it be dangerous? It has really shaken me up when it has gone into full gurgle, whoosh, knocking mode. Cheers, Dee.

Sounds to me like lack of circulating water, especially as it's intermittent, possibly caused by a blocked cold fill pipe. They typically block inside the tee fitting where the fill pipe joins the system once the system is a decade or two in age. If it IS blocked, then the fix is to drain, cut it out and replace it with a new one, then refill and recommission.

It's not very likely though, as yours would have had a new cold fill tee fitted when it was converted from semi-gravity to fully-pumped, presumably when the new boiler was fitted four years ago.


Cheers, Mike

I think I have a similar problem to this lady

//www.diynot.com/forums/viewtopic.php?t=71217

If anyone has any suggestions I'd be grateful!

Hi guys,
I have an update. On Wednesday morning the whole caboodle went off again, only I shut everything off before it could shut the boiler down. In desperation I called in BG. Would you believe the blasted thing worked like a dream while he was here so he wasn't able to identify exactly where the noise was coming from or what it was. The engineer has just gone. He checked the header tank in the loft but said it looked OK. He did say though that a 'H' join had been used between the open vent/cold feed pipes when the new boiler was put in 4 years ago, and that this can be OK. However, the boiler manual said a 'T' fitting should be used. He also said the auto vent on the cylinder needs raising, it's a bit too low. He did say he suspects that air is being drawn into the system which is quietly circulating around until the pressure builds up enough for it to need to find a release. Hopefully by re-configuring the open vent/cold feed and raising the auto-vent on the cylinder the problem will be erased. Well guys, what do you think? Quoted £227.00 for the work. Any comments appreciated.

I had a similar problem that lasted for months. I tried everything but it turned out to be one of the many thermostats in the boiler that had failed. This thermostat stops the pump turning off when when the boiler is hot but the set temperature for the hot water of central heating is reached. When it failed the water in the boiler got very hot, turned into steam which caused horrible noises in the pipes and afterwards was heard rushing round the system. Since the thermostat was changed the system has worked perfectly. It might be worth checking the thermostats are all working OK or just replace them. BG did it for us at the annual service.
Tony

Hi Tony,
Mine has actually been making the noises even when the boiler has been on for a few minutes, before the water has had a chance to heat up at all. The pump seems to be going on and off OK with the usual slight over-run at times. The BG man serviced the boiler while he was here as well. However, he did not turn the hot water on at any stage so I assume he would not have picked up any thermostat problem. Is that anything to do with the PCB board?(Or perhaps he did not need to).I have to say though that he could have been here for the whole day and not heard the noise, there seems to be no ryhme or reason to it at all. I have tried looking at idiots guides to the plumbing and heating systems but I learn better by having someone teach me, so I am struggling to get to grips with it all.

I`ll do it for £200........and travel from Sussex

Thanks Nige!!
From your comment I gather it is rather a lot for what is involved. On the plus side if they cock it up in anyway at least I can get them back. As my sons have said, "It's a minefield out there mum" (Thanks lads!) Anyway, by this time 2020 I should have grasped the basics and be well into the loop of being able to self-diagnose, repair,
make a bodge job and have to get an expert out to re-do it. (Well that's what's happened with most of the things I have tried to repair by working out of a DIY manual so far, so why should things change!) Many, many thanks to all of you for giving me your advice. I will post and let you know how things go when they have been to fix it. Hope you all have a superb christmas. Many thanks.