Can you have sludge build up in the DHW heat exchanger?

[nikon70]

simple question...

Can you have sludge build up in the DHW heat exchanger?

thanks

 

[mickyg]

abso-flaming-lutely

in actual fact it will probably be the first place for it to collect

 

[petit_pablo]

It wont be sludge but it will be sludge related. The heat exchanger can be blocked with flakes of muck/rust from the system

 

[nikon70]

basically i am trying to claim on my insurance to have my main heat exchanger wither descaled or replaced.

the engineer who came out to diagnose the fault said that it was scale build up and they would need to get authorisation from my insurance agency.

i called the plumbers today and they said a power flush for sludge is not covered.

i am trying to prove that its not sludge its scale...

symptoms:
have got very slow hot water coming out of my hot taps

i know in the central heating you can have sludge but i have been told its more likely to be scale build up for hot water

any comments on that?

 

[nikon70]

from another forum:

I service/repair many of these and I have never seen sludge effect the DHW delivery.

 

[superdupergasman]

If it is slow water delivery then it will be a scale build up however if the water coming out the tap has the correct flow and pressure but is cool due to the boiler not heating it correctly then it may be a resricted Plate Heat exgr.

 

[nikon70]

the flow is like a hamster peeing on your hand (a little over exaggerated)

but the temperature is hot as it is suppose to be.

so you concur that it is scale build up??

 

[mickyg]

so you concur that it is scale build up??

yep..assuming that any inlet filters have been checked for blockages

 

[nikon70]

i have no idea if they have checked the filters... the guy that came to service it only checked the gas pressure and that there were no leaks...

i can say that i am not happy with plumbrite they dont seem to know what the hell is going on.

i know a fair amount being a builder but gas and boilers are not my thing.... so i am only going on what i have picked up and what im being told on here and my fellow builders...

 

[bengasman]

some boilers are more prone to it than others, what make is yours?

 

[nikon70]

vokera sabre 24 (i think its a 24 without checking)

combi

 

[Deleted member 105431]

vokera sabre 24 (i think its a 24 without checking)

combi

These are not the best boilers in the world, if not installed to a clean system (should've been powerflushed at installation) any boiler is prone to blocked plate heat exchangers (ch side). If you live in a hard water area you should have some form of scale prevention such as a hydroflow/magnetic inline/combi mate etc.

 

[nikon70]

dangermouse ...
i know CH it happens...
should not happen to domestic hot water??

 

[Deleted member 105431]

dangermouse ...
i know CH it happens...
should not happen to domestic hot water??

no it should not. It's more likely to be a blocked filter, restrictor, flow adjuster or stopcock/isolation valve partially closed.

I would isolate cold mains by isolation valve, undo mains inlet and place bucket underneath and reopen isolation to see what flow is like INTO boiler before filters/adjusters/throttles.

 

[nikon70]

checked the pressure going into the boiler...
same as much as the cold tap also.

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