1 year ventilation system, clarity, facts, electricity costs

In principle, it is correct that the chimney sweep must be on board from the beginning, otherwise you can end up with a nasty surprise. But usually, proof that a ventilation system does not exceed 4 Pa for liquid fuels and 8 Pa for solid fuels is sufficient. This is usually enough. I do measurements myself and have thus avoided installing one or the other pressure switch. However, there were also chimney sweeps who didn’t care about such a measurement protocol. But anyway, the chimney sweep has the final word. Regards M. O.