Hi, I recently had a problem with my 16yr old Potterton Netaheat boiler. The pipes leaked damaging the heat exchanger. I have Emergency Cover through my insurance company who sent a Homeserve engineer to have a look. He reckons a new heat exchanger would cost £389 +vat and take approx 4 hours installation. Does this sound about right taking into account the boiler's age or are they taking the michael? Any re-assurance would be much appreciated. The total bill's just under £700, £500 of which I'm covered for.