I have a house that I rent out and I am in the process of getting it ready
for the next tenant. Whilst decorating I have had the CH on. Today I
noticed above the flue on the outside wall there was a tall triangle shaped
area of water beads, similar to what you would see on a newly polished car.
I am presuming this is the warm air from the boiler condensing on the cold
wall. I have never noticed this on my own house but that maybe because the
houses are different builds. My rented house is a early 1900 terraced house
built of traditional smooth faced red bricks, where as my house is a modern
build rough faced design. Is this normal or is the boiler trying to tell me
something? I have had the Landlords Safety Check done within the last 3
weeks and they gave it the all clear. If I had noticed it before then I
would have asked the gas engineer but unfortunately I only noticed it today.