Warranty's for me are simply a means for me to sell a boiler it really doesn't matter to me beyond that what they do or don't honour as I make it clear to the customer that a warranty is like most insurance assume its worthless and covers nothing and you will be pleasantly surprised if it in fact does cover you in the event of a part failure. I do wish however that boiler warranty's were essentially a return to base for refund style parts replacement scheme that any engineer could make use of providing the affected boiler was within warranty. Perhaps if you agreed with the manufacturer a set rate that you would charge the customer for a warranty repair and they provide the replacement part for free as long as the faulty part is returned. And the customer just applied for the repair charge as a rebate from the manufacturer.