our boiler which is about 5 years old has a leak coming from the main heat exchanger and creating huge puddles on floor! the leak seems to get worse when hw demanded and i'm concerned as water is leaking all over electrics on the inside of the boiler. however, there is no fault regestering on display and heating is working fine, pressure remaining fine too? should i turn the boiler off (seems madness in this weather!) would be grateful for any advice, Lauren