Combi Boiler query on damp patch on outside wall

[CJ2016]

Hello,
I'm unsure if this is boiler related but I have a damp patch on the outside wall and I have been topping up my boiler more often than I think is necessary. The cold water pressure seem to lessen occasionally too. There are no signs of any damp inside, under the kitchen units as I have removed all the kick boards and it is bone dry but due to the outer wall being wet I can smell dampness as it's never had a chance to dry out in this weather. I recently had the rendering redone along this area thinking it was old and perhaps cracked allowing rain water to enter but it's actually got worse since it's been rendered. It is wet for about 8 feet along the bottom of the wall. I am on a gradient where I am at the highest in the terrace so it can't be coming from any other houses. I've tried to download photos if that helps? There is no sign of any leaks from outer pipes and the roof tiles/gutters look sound? Any suggestions please?? There is a small pipe on the wet area and wonder if perhaps it's damaged in between the bricks seeping into the cavity, which has been insulated some years back. Could this pipe be part of the central heating system as the other pipes are on the outside wall leading from the combi boiler.
Any suggestions please?

 

[Riley]

Hi and welcome along. It might be useful to take a picture further back so we can get the bearings of where the boiler is including the flue. Is there a 15mm copper pipe coming out of the wall which turns back on itself to to point at the wall. From what you've said it sounds a bit like the pressure relief valve terminates in the wall. ?? Better pics would help though

 

[Unregistered]

Hello, thank you for getting back to me so quickly, the last photo with the brick work along the middle of the picture has these pipes you are talking about, this is the wall at the back of the combi boiler which is located about 3 feet higher than these. The vent is even higher still. The third photo 69x577 shows a wee pipe coming out of the wall which is bone dry. If that helps?

 

[Dotty]

Please log back in.

 

[plumben]

I'd get a damp expert to come take a look,
could be rising damp or water could be getting in the rendering higher up and running down between the wall and rendering and coming out at the bottom

 

[jonnyswamp]

Could be water ingress through the clay vent, is the o/flow pipe still connected to a cistern anywhere (pic 3) ?
Had this problem yrs ago, where a fill valve was passing and instead of escaping via o/flow pipe, water was going straight into cavity due to a split in the pipe (actually, it was rodent damage but thats another story)
Check if the o/flow pipe is still in use, if so check fill valve
The last pic seems to show a pressure relief pipe terminal and a drain off, presumably for the central heating, are these anywhere near your damp problem
Also check the obvious, leaking gutters or downpipe directly above

 

[erion]

If you are filling the system frequently then there most likely is a leak somewhere but dont jump to conclusions and assume its there where the damp is. Get someone to look at it. Whats on the other side of the wall?

 

[CJ2016]

Thank you. The vent is quite low but it seems to be bone dry. the little copper pipe beside this is redundant and it doesn't go anywhere as I tried to place a rod in it but got as far as about 4 inches in and is also bone dry. I could fill this in? The central heating pipes are around the corner on another wall and are not near the damp patch. It may be an idea to get the gutters checked out as it would be cheaper just now than getting a structural engineer out as it may have nothing to do with the central heating. Thank you again.

 

[CJ2016]

The wall that has the damp patch is on the other side of the washing machine and sink. The damp patch appeared about 2 feet away from the drain from the sink as I thought it might be a crack in the cast iron down pipe from the sink, this would be a simple solution if this is the case, but as the patch didn't appear around this area, it seems unlikely I think??
But you are right, I don't want to assume it is a boiler problem as the damp patch is on a different wall.

 

[Sparkgap]

Where's the DPC? Have you ended up rendering over it?