Hi! We are having a problem with our(the landlords) boiler or the programmer. The boiler is a Baxi solo3 and the programmer a honeywell 6400. We have not had any hot water since yesterday, I just can't get it to work. When I put the HW on the CH comes on instead. Is this going to be difficult and costly to fix, because we don't have our landlords phone number And so we'll have to pay for it ourselves if we want to have a wash before next week.