You can contact your annual boiler service Walsall and get it checked. Another sign to look for is the smell. A faulty boiler often emits Carbon monoxide. If you find your boiler emitting a smell, it means your boiler is producing carbon monoxide.If you feel that the efficiency of your boiler has reduced and it needs a replacement or repair, then you must call a serviceman from Gas boilers Lichfield to determine the exact problem and find a solution.