okay, this is a long story, but please bear with me...
Summer 2006 my boiler broke down... we left it till it started to get cold before we fixed it. Turned out we apparently needed a new ignition pcb. We replaced it, and had the system bled and all was well.... or so we thought.
Last November everything stopped working again... in comes plumber number 2. He replaces the pump, after identifying that it had seized, and tried to test a few things on the boiler. After lots of running up and down to the emmersion tank, it seems to be sorted. Nice and warm. But 2 days later its broken again.
Eventually we manage to get another plumber - having been let down by plumber number 2. They come in, do a powerflush on the useless microbore system we have, and fiddled with the boiler, changed ignition PCB again, changed the flow switch sensor, and the two temp sensors that are in the top of the boiler.
Still no joy. After about 30 seconds of being on, the boiler locks out and shuts down. The pump is still trying to work... but the ignition won't come on again.
Plumber number 3 came out again yesterday and said that it must be the heat exchanger is limescaled up and is giving a false reading... meaning that the limescale is getting hotter than the water in the pipes, so the temp sensor thinks it is hot enough and then cuts the boiler out.
My partner didn't think this would be the case and signed up for one of the manufacturers engineers to come out, who has told us there is an airlock in the system.
Now we really don't know what to believe. Do we need a new heat exchanger, new boiler, or do we have an airlock!?
If we have an airlock, how the hell do we get rid of it?!?
Please help, the 3 months of using oil filled rads is costing me a fortune :(