Always better to contact the manufacturer who will recommend an approved engineer in your post code area and will have knollege of their appliances and may be able to repair on the first visit. You mentioned pressure switch and tcb, either you have heard the engineer wrongly or he is not compitent as it should be P.C.B. (printed circuit board) so my advice is to look at the lable under your fire for the manufacturer and email them
davegas
February 2009
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