boiler keeps switching off

[cuewoz]

I have a baxi solo 3 30pf and I just needed to get a new pcb, but now the boiler fires for about 10 mins but then goes and turns off.

btw i also just fitted a new radiator in the bathroom.

I don't know too much about heating systems as this is my first house.

Any help would be apreciated
Thanks

 

[ChrisR]

You got some air trapped in there when you changed the rad, so it's overheating. Look e.g. for a vent by the HW cylinder.

 

[cuewoz]

i bled the radiator till water started to come out.
i will try and find a vent, what do they look like?

 

[footyfan]

Im having very similar issues after draining my whole system (yes its been re-filled ), i had a hunch it was trapped air but as above i dont know what vents look like, ive had the pump off to flush the crap out, impeller seems fine ( a tip from another plumber).
So any help on the location and visual of 'vent' could help two families from getting any colder
Ive used this site many times for reference, as you can see this is my first cry for help that i cant find in other posts. Great site, great advice.

EDIT
Just to update, ive managed to get it going again by bypassing the whole heating controls and manually running the pump to get the water flowing round the system sending all the air to the tops of rads and 3way valve which seemed to be the highest point and releasing it from their and re-bleeding the rads. When it sounded 'smoother' i swithced the system on and bingo, boiler fired, stayed on (for now) and all seems better.
Hopefully we'll have hot water now, which the problem originaly that led to the sytem drain.

 

[cuewoz]

i found what i think is a vent next to the hot water tank, and opened but only a small amount of air came out, i also opened the screw end of the pump but this just let a small tricle of water out.
I counted the turns on the radiator valves and set these to halh( eg most were 5 complete 360 degrees and I opened 2.5 turns) .
We also half closed the 2 red valves from the cold water tanks?

I now at least can turn the radiators on, but they still keep switching off, at first they stay on about 45 mins, but they switch off quicker as time passes, it auto refires after about a minute.

Also if I set the thermostat knob on the boiler from 6(max) lower it swiches off (pilot and all).

 

[stardanny]

Do the boiler get hot after switching off? Maybe pump is not removing heat from boiler fast. What speed knob on pump? How old is the pump?