The bathroom I have in my flat is enclosed and extraction is by timed fan. If the bathroom becomes really steamy from bath or shower it starts to develope a really stale smell about an 1/2 to a hour later. I have tested the problem out and it is not a drainage problem and appears to be caused by the steam. I have tried leaving the fan on for ages afterwards but the smell still appears. The hot water is provided via a combi boiler. I live in a development of identical flats and this problem only appears to affect my flat.
Has any one any idea why this happens, is it the steam, water from the boiler exchanger, ventilation or reaction with the painted walls, I am at a loss to solve the issue
