Cleaning a plate heat exchanger Worcester 40cdi

[kinhell]

Is there anyway of clearing a semi blocked plate heat exchanger on a Worcestor Bosch 40 cdi without removing it.
Central Heating is fine but the hot water starts off hot and then only warm.
I suspect sludge build up in the system as I'm sure the guy who fitted it didn't put an inhibitor in. I added some last April when I had to empty the system.

 

[petit_pablo]

Not really no. CDi's are a bit tricky to get plates out of too

 

[kinhell]

Would sludge remover in for a few weeks loosen up the stuff in the heat exchanger?

 

[petit_pablo]

Would sludge remover in for a few weeks loosen up the stuff in the heat exchanger?

Might do, it might move more into the heat exchanger too

 

[kinhell]

Thanks for your replies. Does sludge remover dissolve the sludge or just loosen it.

 

[onlyfitidealboilers]

loosen. Powerflush system then add x100 inhibator sorted only cost around £500!

 

[OilLecky]

I thought that the worst build up of scale was in the "hot water" path through the heat plate exchanger. i.e. where fresh cold water is heated to go to the hot taps. This is always fresh water and will always carry more minerals ready to deposit when it is heated, so flushing, if it works, will only be a temporary measure. The inhibitor is in the closed circuit system and will not keep the "hot water" path clear.
You need a "Combi-mate" or a water-softener and a new heat plate exchanger.

 

[Agile]

You may imagine that and in your area where the water can be quite hard that could well be your experience.

However 99% of these problems in most areas are dirt in the system.

It is possible to dissolve it with citric acid introduced just into the boiler circuit. But this required considerable knowledge and skill and few professionals even do this.

The water parts on cdi boilers are very difficult for most professionals and many usually suggest calling the manufacturers for a fixed price repair. I am not sure if that covers blocked plate HEs though.

Tony

 

[OilLecky]

You are correct Agile! I have now looked at where onlyfit lives....Aberdeen....lovely soft water.
What type of water does the OP have?

 

[kinhell]

I didn't get around to reading your replies and rang sentinel and they said that their x800 product ususally used for power flushing usually shifts sludge from heat exchangers. I went and bought some this morning.

Just thinking about this , there must be 2 circuits in the heat exchanger. One for cold water to get heated and one from the heating circuit which heats up the HE and thus warms the water for the taps. Doesn't the water only go around the plate heat exchanger when there is a demand for hot water or will it still go around when the heating is on? What I'm thinking is that will the sludge remover only go through the heat exchanger when I have the hot tap on?

 

[Agile]

Citric acid is best.

If you must try the X800 then only put it in the boiler and operate the boiler with heating isolated and in the DHW mode with not too much flow.

Best to start with DHW temp at min and slowly increase it.

You might have to have a few goes.

I would only use citric acid as that dissolves sludge. Those who answer the phones at Sentinel and boiler companies dont do hands on work!

Tony

 

[kinhell]

Sorry for my ignorance but how do you just put it in the boiler and not the whole system?

 

[onlyfitidealboilers]

don't mean to be rude chaps but how do you guys know its blocked wit scale? it may just may be with sludge from ch circuit!

 

[petit_pablo]

Haha i can see this going wrong! X800 out the taps should be nice

 

[Happyplumber]

aluminium main heat exchanger and acid?????