overheating problems!

[macca86]

hi, have a problem with a glowworm energy saver condensing boiler on a y plan system,the problem is the boiler runs ok for 30 mins or so water and heating gets up to temp then the boiler starts making a banging noise and cuts out,to get it going again it needs to be reset by the red stat under the boiler.
The pump is running and upstairs and downstairs rads heat.hot water is fine.
can anyone suggest what could be causing it?
could the pump be running to slow even tho it is set on 3?
thanks

 

[seco services]

poss faulty boiler stat.

 

[macca86]

could it be down to dirt in the system? how can you tell if the pump is running fast enough and whats the best way to test the boiler stat just put it on min and see if it cuts out and comes back on without overheating?

 

[macca86]

am i correct in saying if the upstairs and downstairs rads are hot and it takes around 30 mins to overheat the pump would be working ok?

 

[seco services]

yes pump sounds ok or boiler would only run for a few mins.

what happens with the boiler stat turned down ?

 

[macca86]

not sure going to check tommorow the actual inside of the boiler is in a bad way looks as though it may of leaked inside in the past is this common with these boilers?what would you narrow it down to then as to why it overheats also it wont come back on unless i press the overheat reset.another confusing thing is it heats/shuts of and reignites and comes back on within this 30 min period as if the boiler stat is working but then all of a sudden theres a banging noise and the boiler shuts off and overheat and can only be restarted by presseing overheat stat reset.then it comes on for a couple of mins and overheats again.

 

[seco services]

i take it its not seen a service then.

 

[macca86]

no doesnt look like it,was all messed up inside really dirty but all cleaned out now,looks as though its just been caught in time before the case was corroded through,however if i set the stat to min and it doesnt cut off within ten mins or so this would suggest the boiler stat also going to take a water sample.i also noticed the 3port valve was not motoring over stuck in the midposition, however its always used on heating and hot water anyway,this wouldnt have anything to do with overheating though would it.

 

[TheBoilerMan]

Those energysavers were one of the first available condensing boilers and they are notorious for causing sludge in systems. can i take a guess that your system water is bright orange?.
suggest you replace it asap or you will be having one problem after another.

 

[macca86]

boilerman system was full of sludge causing restriction in the system causing it to overheat,time for a new boiler
thanks for your help