Help - Noisy Boiler and DIY Disaster

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Hi all,

I could really do with some help, I've looked around the form and followed some advice, but not reached a resolution.

I moved into a 14 year old house in October 2014. The house is fitted with a Potterton boiler with and F&E tank in the loft and a hot water cylinder.

When we moved in, it was warm enough not to need to use the heating, but when the boiler was on, it was quite loud (I now know it was kettling).

Around 2 weeks in, I managed to screw straight into one of the micro bore heating pipes when hanging a curtain rail. Ouch. I really could have kicked myself.

Anyway, ended up calling a plumber to make good my damage. While looking around the system, he pointed out that he thought the pump was mounted the wrong way, I.e. the flow was in the wrong direction. Honestly, I did not think too much about it, I thought he might be wrong or wanted another job, and the hot water worked fine.

Anyway, it started to get cold and I used the heating for the first time. The first morning, I was woken by a loud banging from the rads and a gurgling sound from a few. I thought the repair had sprung a leak, but it wasn't that.

I bled the system and considerable air came out. The next day was the same, and so on.

Reading this forum, I thought it might be corrison related, so over Christmas I drained part of the system and added Sentinal X400 and left this to run for three weeks. I drained and flushed the system and refilled it with clean water and Sentinal X200 and X100.

The water that came out during the flush was milky black, but the system was drained when I had my mishap, so some of the sludge may have been removed at this point.

This has reduced the kettling but the gurgling is still there, as loud as before. Two of the rads need bleeding every day.

I now wonder if the plumber was right or whether I am missing something else. Not knowing how the system ran before, I'm not sure if I have created the mess, but I have noticed that the previous owner took other shortcuts around the house, so it is plausible that he fitted the pump and got it wrong.

Any help would be much appricated, its been driving me bananas for weeks now.

Thanks,

Ash
 
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Youre going to have to post some pictures if you want some proper advice. Pictures of the pump, pipe configuration around the pump, motorised valves, feed and vent entry to the system ect.....

The more pictures the better.

Get snapping.
 
The hottest pipe at the boiler is the actual flow.

But you have not bothered to tell us what boiler model you have otherwise we could tell you which boiler pipe SHOULD be the flow!

These are very simple aspects to diagnose!

Tony
 
Hi,

Thanks. The Boiler is a Potterton (I did mention that), but the model is a Suprima. All the pipework running to and from the boiler is boxed in, so I was hoping for some guidance prior to taking all apart.

As requested by TCCHeating, some picture are below, I appreciate that it may not be clear, but the marked flow direction on the Grundfos pump is away from the silver motorised valve.

I tried, as suggested somewhere else on the forum, running the pump at the lowest setting (1 rather than 2) last night, and while the noise was quieter, it was still there.


Ash


 
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+1

Pump is pumping in the wrong direction. And more than likely overpumping straight up the vent pipe as well.
 
Thanks all, so it appears that the plumber was right.

Is there anyway to confirm that this is the case, i.e. an obvious sign that the pump is plumbed the wrong way round? For example, can I check the vent pipe to confirm this?

Assuming the pump is the wrong way round:

1) Will that lead to the symptoms I am experiencing?
2) To reverse the flow, is it as simple as isolating the pump using the brass fittings, unscrewing it, and turning it around?
3) If I reverse the flow and it was fitted in the "wrong" orientation for a reason that we are not aware off, will I do any damage by turning it around?

Thanks again for all your help, it certainly has been good to get some confidence / reassurances and good advise.

Ash
 
I suspect at some point a new pump has been fitted, and whoever fitted it has put it on the wrong way around. In your pictures the pump is pumping straight into the air seperator (the feed and vent pipes are connected into this). Before just changing the pump direction, you must check the boiler flow and return pipes are reversed. (I suspect they are).

If the boiler flow and return pipes are reversed. Then simply isolate the pump and change it around.

If the flow and return pipes are not reversed then you will have to swap them around as well as changing the pump direction.

Ps. Pump isolation valves dont always turn off and often leak. So you would be better off draining the system before removing the pump
 
Thanks again. Its starting to make sense, but I could do with some more guidance on the boiler flow and return pipes.

I know the boiler is the original boiler and the boxing in above the boiler is also original. Without taking the plaster board apart, is there an easy way to check if the flow and return pipes are reversed? For example, can I access this from near the pump? Could the flow and return be swapped while the boiler was in situ, or it is possible to make the swap elsewhere in the system?

If it helps, the reason the plumber thought the pump was reversed was because the pipe lower pipe entering the hot water cylinder was hotter than the upper pipe (when the system was 1st turned on), which he thought was usual.

As you can tell, this is my first experience of issues on a boiler, so I'm a little new to it all.

Ash

 
It's a shame you doubted your plumbers diagnosis.

That's true, but having just moved to a new area and needing a plumber quickly, I simply found the first one on Yell.com that was available to come around the following morning (we have two young kids and need hot water).

You hear so many stories, and while he was more that competent in the repair and a really nice guy (as I suggested, he stayed while the system refilled - just to check his work), his comments were made simply by touching one of the pipes.

Just goes to show that you don't know what you don't know.

Ash
 
Flow pipe on that boiler is the left hand pipe coming out of the top of the boiler. Youre going to have to get into that boxing to check it. Or you could just make a small hole (just enough to get you fingers in to feel the pipes) and fill the hole when youre finished. As I said before, i strongly suspect that you will find they are reversed. So all that is needed is changing the pump direction. But you must check first.
 
OK, great. Well, I've broken into the box, which was only 3mm ply, so it just prised off, and there are, as you suggested, two pipes coming out of the boiler (see attached).

I am guessing that when I switch the central heating on, I am expecting the retrun (right hand side pipe as you look at the boiler) to heat up first, in which case, this is the flow and the pump simply needs to be installed the other way round?

Thanks again for your help. This really is a great forum.

Ash

 
OK, I've switched on the CH & HW, and within a second or two the right hand pipe was warm to the touch, and the left hand pipe (as you look at the boiler) was cool and getting cooler.

After a while, the left hand pipe started to get warm.

I've found the on line installation instructions for this boiler, which again, re-confirm what everyone has said:



1) The pump should flow towards valve
2) The left hand pipe is the flow, and therefore, my logic is that this should get warm first

I am convinced, based on everyone's comments (especially TCCHeating) that the pump has simply been installed in the wrong direction.

Just before I start to drain the system and reverse the pump, I am hoping that you could confirm that I am reading this right and that swapping the pump direction is he right thing to do?

Thanks again,

Ash
 
Yes. Swap the pump direction and all should work correctly. Classic case of engineer brain freeze! Changing a pump should be simple but youd be surprised how many get replaced the wrong way round. I've even seen it when the pump was changed by a british gas engineer! Pretty unforgiveable.

Whilst youre at it. Clean all those green bits around the joints on the pipework with some wire wool. That is flux residue eating into the copper and could cause problems in the long term.
 

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