Glow-worm exchange plate

[sylvian]

Please bear with me on this. I have had my 30CXI for 13 months now. During that period the exchange plate has blocked up 10 times. Glow-worm passing the book blamed the installer. The installer flushed the sytem twice making it 3 times the system was flushed and still the plate blocked up! The last time it blocked up I actually took a day off work to see the plate myself. As the engineer showed me the debris inside the plate as he was cleaning it, I noticed it was only coming out of one side. When I asked why this was, he explained that that was the mains water supply side!! When I asked why then did Glow-worm insist on blaming the installer when it was the mains supply all along, he couldn't answer me. Now we know its the mains supply. They have tested the water but I am still waiting for the result 9 weeks later!
I have since placed a piece of my wifes tights over the pipe to stop any debris entering the boiler. There are no appliances between this section and the boiler. There is also a filter on the inlet to the boiler, but still it has clogged up and again we have no hot water!!!!
I can only assume this debris is building up in the boiler itself somehow as both the filters, the one I put on the pipe and the one into the boiler are clean.
Any answers for me PLEASE!!!!

 

[gasgeezer]

you have been mis-informed the debris will be in the system side of the dhw exch. Which i think from memory is the top, possibly the l/h side will be more blocked as this is the outlet side.The bottom holes will be clear as this is mains water. It cannot have been flushed correctly to have blocked 10 times. A further problem is flushing with the boiler in situ as this tends to push the deposits into the h/exhangers narrow water ways. I personally use dsx100 and flush add cleanser drain then add inhibitor. Power flushing tends to break large pieces of magnatite off and block the plate and also loosen it so months later it blocks, if you have double rads it wont do both sides.In your case fit a strainer or magna clean filter it will help

 

[sylvian]

If that is the case how come the central heating is working fine, but we have no hot water?
Also the system is brand new ,radiators and boiler, would there be much debris in the system anyway?

 

[sylvian]

I have actually found the exchange plate that was previously taken off and the debris is definately coming out of the bottom not the top! The top is clear. Can anyone explain that one?

 

[ChrisR]

Started typing (the bit after the line) this before your last post was entered.

• What colour was the material which was blocking the plate heat exchanger?
  Do you have very hard/soft water?
  Do you have a water softener?
  How hot is the tap water you get, when it 's working - is it particularly hot? (I mean over about 65 but I doubt you can measure it)
  Did anyone suggest at any time that the heat exchanger was perforated/holed - is that why you have a "spare"?

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The whole thing sounds bizarre! 10 times in 13 months - anyone else heard of that, whatever the cause??

The usual problem is old sludge blocking the boiler side of the tap water heat exchanger. The waterways for the CH are bigger so you don't see a problem with that.

Mains water can have flakes of rust from tron pipe in it, but those are stopped by the filter(s).
Sludge is caused by corrosion, but its hard to see how you're getting the problems you are if it was flushed vaguely normally. A new system wouldn't normally have much to flush, I just wonder if for some reason your radiators were badly rusted inside. Were there ANY old parts of ch system reused?



A filter on the return pipe to the boiler, and or a magnetic grot grabber, as GG says, would be a good thing to try.

 

[Agile]

I still think that its the primary side that is getting blocked.

In any case what colour is the blockage???

An all new system is often the worst when its not properly cleaned. Too much flux and no cleansing.

You keep on saying that the installer "flushed" the system. I would ask how you know that what he was doing was the right thing? What chemicals did he use?

You said it was the "bottom" of the plate HE which was blocked. How do you know which is the bottom when its out of the boiler?

When you say you have no hot water what do you mean??? No water at all or just water thats cold???

Now the key, whats the colour ???

Tony

 

[gasgeezer]

just remembered the dhw inlet should have a flow restrictor/filter fitted at the isolation valve. Thus eliminating any debris coming into the boiler via the mains. Surely as it is in warranty glow-worm checked this and or took a sample for analysis. p.s if the boiler when fired at full rate is it showing a F14 code if so definetley a blocked h/exch. also sometimes it will go down the heating side via the by-pass are any rads close to the boiler heating when not called for

 

[ollski]

You said it was the "bottom" of the plate HE which was blocked. How do you know which is the bottom when its out of the boiler?

I usually find it is the opposite side to that which is marked top

 

[gasgeezer]

the h/exch will only go in one way as the fixing points are off-set the top always has the writing on it, as agile said what colour is the debris another thought are any taps/shower heads being blocked as they will be mains fed on the cold side

 

[ChrisR]

Already asked about the colour!

 

[sylvian]

Thanks ollski you took the words right out of my mouth. The exchange plate actually says 'TOP' at the top. So the bottom is opposite!
The radiators are working fine. It is not a flushing problem. Even though some of you don't want to believe that for some reason!
The colour of the debris is light brown, black which crumbles when rubbed, and some sandy deposits. The water coming out of the taps is fine as it has always been!
The mystery deepens!!!

 

[Gasguru]

Why don't you install a filter/strainer on the mains

http://www.arrowvalves.co.uk/productdetail.php?id=66

 

[sylvian]

Gasguru. Where can i get a filter/strainer from?
Cant see them in B&Q.

 

[Gasguru]

You won't find them in B&Q thats a diy shop.

This is just an example, there are many other similar products.

Click on the "sales agents".

 

[sylvian]

engineer came to the boiler again yesterday and had apparently rectified the boiler but left a message stating he had to order a new part. Still no hot water and apparently he has ordered a new pump. Does anyone know if this will rectify the problem