We bought a new house from a small local builder 4.5 yrs ago. It had a floor standing worcester bosch combi boiler. Every year it has broken down and we have had to replace lots of parts including the circuit board 2 months ago. Our electricity and gas bills have been enormous and our water bills have just increased by 75% . We noticed a month ago that the flooring in the kitchen was lifting and realised we had a leak on the boiler. After investigations from an independant plumber, the whole boiler has been installed and connected wrongly from the beginning. The cold outlet was connected to the hot pipe and vice versa. This has resulted in the whole of the boiler being stripped out on my kitchen floor and replaced. It is going to cost 100's of pounds in repairs and my kitchen floor is ruined. Do i have any recourse to the builder or the plumber who installed it. We have Zurich insurance on the buildings who say it's not covered but not NHBC. It is not the first thing to go wrong with the plumbing, I am at my wits end and any advice would be appreciated. I don't want to threaten legal action if i can't back it up. Thank you.