Polystyrene beads bottom of boiler + water dripping

15 Dec 2008
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United Kingdom
Hello all!

A damp patch on the wall under my boiler started forming a couple of months ago. Unscrewing a panel below the boiler, a whole bunch of polystyrene beads came out. I understand these would have been used as wall insulation.

The boiler was only installed 3 years ago (had a service last year), so I'm not sure why the beads are suddenly coming out now. There are a number of gaps around various pipes going outside It gives on to a balcony), but it's impossible to figure out where the beads are coming out from. There are a few of them outside as well, but most of them seem to be collecting on the inside.

Similarly the water - there's not a dripping as such, could easily go a few hours without seeing anything. But I did see a couple of drops of water accumulating in the gap where the white pipe on the left is in the attached picture, so it's either coming from around that pipe, or at least ending up there.

So I guess the questions is is this something that the boiler servicing engineer could deal with? Related to that, is there anything I can use to safely try and block up the various gaps around the pipes in the boiler? Fire rated expanding foam?

I guess I have two problems - the polystyrene insulation coming out and the water dripping. They must be related but just wondering if there's anything I can try first without having to get the boiler taken out and re-installed which could get expensive!


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