Before the day of the installation, one of our surveyors will arrange a time with you to check several things, including. When your flight's delayed, all airlines should compensate you automatically are you with us? I've used various drain unblocks in the past this is streets ahead of any of 'em ! this product is amazingly good , and i heartily recommend it to anyone who has had annoying blockages. We had a combi okay, hot water whenever you require it, but if somebody turns a tap on.