I have a sabre 24 boiler which has run problem free for 4 years. Recently it has started to show a red light after 2 hours running. The heating or hot water does not work when the red light is on.The problem is fixed by resetting but always comes back. Boiler has not been serviced but is this the problem ?
it could be a simple fix as mine was.take off the front cover and in the bottom right you will find a plastic bottle trap.with the use of a small jug,pull off the plastic pipe and drain about a cup full of water.replace and switch back on,it worked for me.