Boiler problems/dry rads

[allg03]

Can anyone help?

At present when I turn on my boiler it fires up, makes noises like there is someone trapped in there and then the overheat light comes on and it turns off.

i thought it might be an airlock and have tried to bleed the radiators. The downstairs ones are okay but the upstairs ones have no water in them. Can leave the key turned for ages and no water comes out.

have been in the loft and checked the tank and this is full.

can anyone give advice on what next?

 

[seco services]

would say you have a blockage in the cold feed from tank to system.
common blockage is where the cold feed tees into the system.
find that section of pipe and place a magnet over it, if it sticks thats where the block is.
you can also remove the nut in the centre of your pump if upstairs in an airing cupboard and if thats dry, theirs no water getting round your system.

 

[bengasman]

Open vents are often full of sludge, your system is probably in need of thorough cleaning job.