Overflowing Expansioin Tank/knocking noises


Postby magseywagsey » Sun May 04, 2008 6:25 pm

Hi can anyone help. I am a single parent (female) have to be careful with money and will attempt to do diy jobs.

December 2006 had a new 3 port fitted central seemed ok some funny sounds but no knocking the man who did it on the side I think put in the system some inhibitor or sludge stuff not sure which. Anyway, come November of last year I put on the central heating all was well for a while then started the really knocking of the pipes followed by the expanson tank overflow to spurt out quite a bit of water and in between all this constant dripping and even though I am not getting the pipes banging the overflow is still constatly flowing. I have changed the float and arm told it was at the correct level but still when I go in the loft drain off some of the water put on the central heating I get this burst of water drom the expansion tank overflow. I have also noticed that the hallway radiatior stays cold, but when I give it a bang with my shoe it is like I have dislodge something and it starts getting warm.
Now could the problem be that the system needs flushing out and it that is the case is it easy to do? Is there something wrong with the float? or could it be my cold water tank (if it does this, because I am not sure) float need replacing and does water from that tank feed the expansion tank? Or is it something more serious and will it cost alot to put right? On a very tight budget. I also have an immersion tank to heat the water in the summer when I dont need the boiler/central heating and when I do use the immersion tank for hot water will the dripping stop?
If it is the case that the system needs to be flushed and drained roughly how much do you think someone who does these things on the side would or should charge?

I think I have mentioned everything and if I have missed something out please ask.

Any help will do
:? :?
Maggie
magseywagsey
Rank: Apprentice
Progress to next rank:
15.8%
Posts: 8
Joined: Sun May 04, 2008 6:03 pm

Sponsor

Simply Build It

Postby briana » Wed May 07, 2008 11:28 pm

[quote="magseywagsey"]Hi can anyone help. I am a single parent (female) have to be careful with money and will attempt to do diy jobs.

December 2006 had a new 3 port fitted central seemed ok some funny sounds but no knocking the man who did it on the side I think put in the system some inhibitor or sludge stuff not sure which. Anyway, come November of last year I put on the central heating all was well for a while then started the really knocking of the pipes followed by the expanson tank overflow to spurt out quite a bit of water and in between all this constant dripping and even though I am not getting the pipes banging the overflow is still constatly flowing. I have changed the float and arm told it was at the correct level but still when I go in the loft drain off some of the water put on the central heating I get this burst of water drom the expansion tank overflow. I have also noticed that the hallway radiatior stays cold, but when I give it a bang with my shoe it is like I have dislodge something and it starts getting warm.
Now could the problem be that the system needs flushing out and it that is the case is it easy to do? Is there something wrong with the float? or could it be my cold water tank (if it does this, because I am not sure) float need replacing and does water from that tank feed the expansion tank? Or is it something more serious and will it cost alot to put right? On a very tight budget. I also have an immersion tank to heat the water in the summer when I dont need the boiler/central heating and when I do use the immersion tank for hot water will the dripping stop?
If it is the case that the system needs to be flushed and drained roughly how much do you think someone who does these things on the side would or should charge?

I think I have mentioned everything and if I have missed something out please ask.

Any help will do
:? :?
Maggie[/quote]

One of the mistakes I made, as a novice DIYer nearly 40 years ago, when I installed central heating in my first house, was to install the wrong sort of valve between the header tank and the central heating fill. I used a normal brass tap, such as you would use on an outside hosepipe connection, which is one way only. Consequently, instead of the expansion flow going back up the fill pipe, it went up the expansion pipe. It has to be a gate valve, which is two way. This will allow the expansion flow to go back up the fill pipe, which is under pressure from the tank above.

The float valve in the tank should be able to compensate for this, so as not to cause it to overflow. But the main problem is that the flush of water back into the tank via the expansion pipe keeps the water in the system aerated, and it could be this air that is causing the knocking in your system.
briana
Rank: Labourer
Progress to next rank:
25%
Posts: 2
Joined: Wed May 07, 2008 10:46 pm

Postby plumbbob » Thu May 08, 2008 1:52 pm

There is a electrical speed control knob on the side of the pump which is probably set to speed three. Try changing to two or even one and see if this stops the overflowing into the header tank.

If the expansion tank itself is not overflowing onto the garden or driveway outside your house, then the float is working properly.

Monitor the temperature of the water in the expansion tank. In cases where the tanks heat to an excessive temperature, there is a chance they may collapse.
plumbbob
Rank: Project Manager
Posts: 1873
Joined: Wed May 07, 2008 9:59 pm

Postby magseywagsey » Thu May 08, 2008 4:34 pm

[quote="briana"][quote="magseywagsey"]Hi can anyone help. I am a single parent (female) have to be careful with money and will attempt to do diy jobs.

December 2006 had a new 3 port fitted central seemed ok some funny sounds but no knocking the man who did it on the side I think put in the system some inhibitor or sludge stuff not sure which. Anyway, come November of last year I put on the central heating all was well for a while then started the really knocking of the pipes followed by the expanson tank overflow to spurt out quite a bit of water and in between all this constant dripping and even though I am not getting the pipes banging the overflow is still constatly flowing. I have changed the float and arm told it was at the correct level but still when I go in the loft drain off some of the water put on the central heating I get this burst of water drom the expansion tank overflow. I have also noticed that the hallway radiatior stays cold, but when I give it a bang with my shoe it is like I have dislodge something and it starts getting warm.
Now could the problem be that the system needs flushing out and it that is the case is it easy to do? Is there something wrong with the float? or could it be my cold water tank (if it does this, because I am not sure) float need replacing and does water from that tank feed the expansion tank? Or is it something more serious and will it cost alot to put right? On a very tight budget. I also have an immersion tank to heat the water in the summer when I dont need the boiler/central heating and when I do use the immersion tank for hot water will the dripping stop?
If it is the case that the system needs to be flushed and drained roughly how much do you think someone who does these things on the side would or should charge?

I think I have mentioned everything and if I have missed something out please ask.

Any help will do
:? :?
Maggie[/quote]

One of the mistakes I made, as a novice DIYer nearly 40 years ago, when I installed central heating in my first house, was to install the wrong sort of valve between the header tank and the central heating fill. I used a normal brass tap, such as you would use on an outside hosepipe connection, which is one way only. Consequently, instead of the expansion flow going back up the fill pipe, it went up the expansion pipe. It has to be a gate valve, which is two way. This will allow the expansion flow to go back up the fill pipe, which is under pressure from the tank above.

The float valve in the tank should be able to compensate for this, so as not to cause it to overflow. But the main problem is that the flush of water back into the tank via the expansion pipe keeps the water in the system aerated, and it could be this air that is causing the knocking in your system.[/quote]

Thanks for your reply. Right at the moment my central heating is off, the boiler is still lit and at the moment I have turned the water off at the room timer, but, I am still getting the constant dripping, so what is causing that now or is it because I still have the boiler lit ? I understand about the air problem, so does my system need draining or is there some other way of getting rid of the air problem? and will it stop the constant overflow of water. I didn't have this last year, mind you the 3 way port at this stage was only working with the heating side as it would not change over it was jammed., but I didn't get any overflow, and when I had a new 3 way port fitted the CH and H W worked ok some funny noises, no knocking noises though, but as the weeks went on it got worse and the pipes really knocked and the overflow started. As I said in my first post the man who did the 3 way port he put some sludge cleaner in the system, could this have started working and caused an airlock in the system. I have also noticed that when I turn off the water at the timer there is some knocking and then a fountain of water spurts out for a while then it settles back down to the constant dripping the same thing happed with the heating, when I turned the temp. down the same thing happened, the pipes would knock and the same spurt of water.

So I think you have answered my problem "air" please confirm and will I have the dripping problem when I turn off the boiler. Do I need to drain and flush the system? Will it be easy or would I need to get some one to do it, thinking of cost here.

Your help and anybody elses would be appreciated.

Maggie
magseywagsey
Rank: Apprentice
Progress to next rank:
15.8%
Posts: 8
Joined: Sun May 04, 2008 6:03 pm

Postby rosebery » Thu May 08, 2008 8:36 pm

@ Briana

"Consequently, instead of the expansion flow going back up the fill pipe, it went up the expansion pipe."

Sorry to contradict you but that's what it is SUPPOSED to do. That's why it's called an expansion pipe.

Cheers
rosebery
Rank: Project Manager
Posts: 2022
Joined: Wed Sep 26, 2007 8:55 pm

Postby rosebery » Thu May 08, 2008 9:26 pm

magseywagsey

You probably have two tanks in your roofspace. A large one which is the CW storage tank and provides cold water to any non mains taps and also replenish the water in the HW cylinder as you draw off the hot. This will have an expansion pipe over it from the HW cylinder. This will be the pipe which goes vertically upwards from the top of the cylinder into the roof. The smaller one is the F&E tank for the CH. This also has an expansion pipe over it but this is connected to the heating circuit. The configuration of this should be boiler > expansion (vent) > feed > pump.

It's not entirely clear to me which of the two is the one we are talking about. I suspect it's the second but can you clarify please. Whichever it is the system is pumping over by the sound of it and there are a number of reasons this could be happening.

If it's coming out of the vent from the cylinder that almost certainly points to a leak in the coil in the cylinder. What happens then is that there is an open connection between the closed part of the system and the open part and the pump just forces the water out of the vent pipe. The solution to this is a new cylinder.

If it's the F&E (sorry Feed and Expansion) for the CH then it could be:

1. CH Pump Speed Too High

Try turning it down and see what that does. Note this will only be a temporary solution.

2. Blockage In Pipework

Needs flushing out if it's sludge or if it's a magnetite deposit it'll probably need that section of pipe cutting out and replacing. I'm afraid you'll need a professional for this.

3. Feed and Expansion Configuration Incorrect

Should be as stated above. If not needs to be fixed.

4. Vent Pipe Too Low

Needs to be raised.

5. Boiler Stat Set Too High or Gone

Boiler overheating. This may also be causing the knocking noise.

Whatever the answer is you are going to have to get someone in to look at it for you. This isn't a DIY thing if you don't know what you are doing. The water coming out of the vent pipe is only a symptom and not the problem. It's important that this is fixed because (as briana said correctly) all you are doing is drawing aerated water back into the system which causes more corrosion which causes more sludge and also wastes a vast amount of heat and fuel although it's unlikely IMO that the air is the source of the knocking.

Hope this is of some help if nothing else to provide some clarification.

Cheers
rosebery
Rank: Project Manager
Posts: 2022
Joined: Wed Sep 26, 2007 8:55 pm

Postby rosebery » Fri May 09, 2008 10:52 am

"but, I am still getting the constant dripping, so what is causing that now or is it because I still have the boiler lit?"

Although our posts crossed but nevertheless which vent pipe is dripping?

"I understand about the air problem, so does my system need draining or is there some other way of getting rid of the air problem?"

I'm not currently convinced this is the problem.

"the man who did the 3 way port he put some sludge cleaner in the system"

Did he flush it out again and add some inhibietr tio the refilled system? Sludge clener is corrosive and it could well be that the coil in the cylinder was getting a bit thin anyway and the effect has been to make a hole. Equally it could have removed some sludge that was blocking a hole anywere in the system.

"I have also noticed that when I turn off the water at the timer there is some knocking and then a fountain of water spurts out for a while then it settles back down to the constant dripping the same thing happed with the heating, when I turned the temp. down the same thing happened, the pipes would knock and the same spurt of water then if the HW is still on."

This points more and more to the cylinder coil. When you turn the heating off (or reduce the temp at thestat) the 3 port valve closes the heating circuit off and the pump will continue to run on for a time. The only place the pumped water goes is through the primary circuit (ie the coil) back to the boiler.

"So I think you have answered my problem "air" please confirm and will I have the dripping problem when I turn off the boiler."

No I don't think it is air. If it were then and the tops of one or some the rads are cold that is where the air will settle and can easily be removed using the radiator bleed valve(s).

"would I need to get some one to do it, thinking of cost here."

Irrespective of cost I truly believe you should. Sorry. Your first port of call might be the guy who fitted the valve and get him to address the problems which only started it after he fitted it. Then the cost should be minimal as if he did it incorrectly (ie by not flushing the cleaner out) then he has a responsibility to fix it.

Hope this is of help.

Cheers
rosebery
Rank: Project Manager
Posts: 2022
Joined: Wed Sep 26, 2007 8:55 pm

Postby magseywagsey » Sat May 10, 2008 4:28 pm

Hi Rosebery

Thanks for your reply and advice.

To clarify it is the expansion tank overflow.

I have been doing some testing and even though it is coming from the expansion tank overflow, I think you maybe right with regards to the cylinder coil.

I have turned everything off the timer that calls for heat and water, the cold water tap to the cold water tank in the loft. I turned on the cold water tap for the bath and nothng happened, I turned on the hot water taps in the bathroom and the kitchen and even though I have isolated the water to the cylinder (there is still water in the tank) it did something to the expansion tank and it started dripping again. I then removed some water again from the expansion tank and tried this again, obviously there is less water in the cylinder, so it has drained more off and the cold water feed is still off and there was no more dripping, all this time my boiler is still on, just incase that has any bearing on this problem./

So I think you maybe right, (please reply and let me know) it probably is the coil and it does have a leak. If this is the case does that mean a new cylinder tank., and will this be anexpensive job to replace it.

I can remember when my ex-partner was putting this cylinder tank in, it was a pig of a job to do.
Answers to your other queries:-

The pump speed is set on 2

The F & E configuration as far as I know is still the same as it ever was when the central heating system was put in, unless the man who replaced the 3 way port did something. Anyway, I don't know what this is and where to look for it.

The vent pipe in right up under the eaves

Haven't touched the boiler stat. Only the knob you set to high in winter, the instructions say you have to do this, at the moment it is on 4 I turned it down just in case this helped, but it didn't.

So perhaps like you say when the man came to do the 3 way port, and put some sludge stuff in the system, well I think that's what he put in, and like you say it is corrosive, it probably has made a hole in the coil if it was wearing thin. Didn't realise that happed to the coil, in fact I did't realise it had a coil in it. sorry bit dumb there.

Look forward to your nexrt post.

I hope this helps you further, which in turn will help me, so I know what to do next, and price things up, because if it is the cylinder tank, Iwon't be able to do that, and I won't ask my ex because I know what the answer will be, even though his daughter will benefit, but, hey not your problem.

Thanks again

Maggie.
magseywagsey
Rank: Apprentice
Progress to next rank:
15.8%
Posts: 8
Joined: Sun May 04, 2008 6:03 pm

Postby magseywagsey » Sat May 10, 2008 5:00 pm

Hi again

It started dripping again when I turned on the hot water tap, so I have now completely drained the cylinder and the dripping has stopped.
Does that help you solve my problem?

If this is the problem, would that cause the knocking noises and the sudden fountain of water I get when the central heating is on when the room stat decides it needs to alter the temp.

The man who did the 3 way port didn't flush my system Because I didn't ask him to do that, and he put the sludge stuff in to help the system, but like you said it is corrosive, so it could have found a weak point in the system or cylinder.

Just something else, where does the hot water come from to heat the radiators, and does the circulate round. Does it start in the cylilnder then move on because that is where you get your hot water from to wash pots etc. am I being thick here, would like to know how that works.

Thanks again

maggie
magseywagsey
Rank: Apprentice
Progress to next rank:
15.8%
Posts: 8
Joined: Sun May 04, 2008 6:03 pm

Postby magseywagsey » Sun May 11, 2008 11:25 am

Hi Rosebery

Just some additional info on the above two posts.

Somehow just alittle, the cylinder is filling up a bit, not alot, when I run he hot water tap for a few minutes it hs emptied it again, jusgt wondering how and where the water is coming from. The cold water tank is still full, could it be from that.

Also not sutre if it is anything to do with the problem, the pipes that come back down from the attic, in my airing cuupboard, there is ne pipe that has a gate vale on it, now this is brtoken can't turn it anyway ceased up. this pipe goes under the cylinder tank somewhere and I can't feel where it goes to after that, not sure whether it goes into the cylinder or under the floor boards to somewhere else. Could this be contributing to the problem as well.

Well that is everything now, can't think of anythinf else to help you.

How can I tell without taking it to pieces if the boiler stat is broken?

Thanks again

Maggie
magseywagsey
Rank: Apprentice
Progress to next rank:
15.8%
Posts: 8
Joined: Sun May 04, 2008 6:03 pm

Postby magseywagsey » Sun May 11, 2008 10:12 pm

Hi Rosebery


Update, Just turned the water back on, there wasn't any dripping at the start, I then turned on the hot water tap, (testing) and low and behold it started dripping. The boiler is still lit and the timer was off so the water hadn't been heated. Central heating off, only usijng the boiler for water at the moment. Does this help you anymore.

Thanks Maggie.
magseywagsey
Rank: Apprentice
Progress to next rank:
15.8%
Posts: 8
Joined: Sun May 04, 2008 6:03 pm

Postby magseywagsey » Mon May 12, 2008 8:26 pm

Hi Rosebery


Just been to B & Q to check out prices for a new Indirect Cylinder Tank, what a surpirise, didn't realise they cost that much. Anyway, had a word with the plumber there, and now it is getting more confusing, he tells me if it is the coil in the cylinder I would be getting blackish water for everyday washing etc. because it would leak into the cylinder. It is not discoloured. So like you also suggested, he thinks it could be the cylinder stat or the boilerstat, or the person who put in the new float and arm has put it in wrong. Does this sound like it could be the problem.

Maggie.
magseywagsey
Rank: Apprentice
Progress to next rank:
15.8%
Posts: 8
Joined: Sun May 04, 2008 6:03 pm

Postby rosebery » Mon May 12, 2008 11:27 pm

Maggie
Sorry not been on here since Friday. Lot of information to adress and me brain isn't properly with it at this time of night.

I'll reply tomorrow (no I won't it'll be today)

Cheers
rosebery
Rank: Project Manager
Posts: 2022
Joined: Wed Sep 26, 2007 8:55 pm

Postby magseywagsey » Thu May 15, 2008 4:00 pm

Hi Rosebery

If the problem is the boiler stat or the cylnder stat how can I tell they are broken, can I tell without having to take it apart.
Also lilke the man at B & Q said regarding the float, could that be my problem and it has been put in wrong or it is a faulty ballcock.
Further advice appreciated.

Maggie.
magseywagsey
Rank: Apprentice
Progress to next rank:
15.8%
Posts: 8
Joined: Sun May 04, 2008 6:03 pm

Postby rosebery » Mon May 19, 2008 12:19 am

Hi Maggie

Sorry for my absence. Word pictures are all very well but theres no substitute for actually looking at it.

From the clarifications of your last few posts it sounds to me like thers a blockage somewhere. So I've revised my thoughts but it's taking lots of toing and froing to get there.

On 9th May I suggested you get someone in to look at the problem.

I haven't changed that opinion, frankly and it's now 11 days later. I really would start with the guy that last worked on it.

Cheers
rosebery
Rank: Project Manager
Posts: 2022
Joined: Wed Sep 26, 2007 8:55 pm

Display posts from previous
Sort by
Order by



  • DIY How to Project Guides

  • DIY how to tutorial projects and guides - Did you know we have a DIY Projects section? Well, if no, then we certainly do! Within this area of our site have literally hundreds of how-to guides and tutorials that cover a huge range of home improvement tasks. Each page also comes with pictures and a video to make completing those jobs even easier!



 


  • Related Topics