Heat exchange plate constantly getting blocked

[Mitch2610]

Hi, wondering if anyone can help. I have a Worcester greenstar 30i erp boiler, it’s about 8-9 years old. In the last 3 years the heat exchange plate keeps getting blocked up with what looks like limescale although I’m not 100% if that’s what it is, it’s light in colour anyway. My mate is a gas engineer and he has to come and clean it out for me every few months as my hot water stops working. I’ve replaced the heat exchange plate already and fitted a limescale inhibitor but neither have been successful. He said it’s common with the Worcester exchange plates but I need a permanent fix, has anyone had experience with this and how to fix it as I find plenty of people with the same issue but never a resolution. Cheers.

 

[ShaunCorbs]

Is it on the top side or bottom side of the ports in the plate ?

 

[Mitch2610]

It’s the hot water side mainly, heating seems to work ok but it does come out of both.

 

[ShaunCorbs]

It’s the hot water side mainly, heating seems to work ok but it does come out of both.

Might be worth sending a sample off to be tested eg mains cold might need to install a combi mate etc

 

[Mitch2610]

Sorry forgot to say it is a combi boiler, it looks almost like sand

 

[Chuck]

If the problem is occurring with public mains water, the supplier will publish detailed analyses of the water in your area somewhere on its website. Check the MIs but, as a rule of thumb, aluminium HXs typically require the pH to be between 7 and 8.5.