ravenheat csi85t boiler

[amcal]

Hi i know many people have been here before but i am down to my last few hairs.boiler will fire stay lit for approx five mins then will shut down and not re-light until cool. ravenheat fault finding not very helpful. last post i looked at points to thermistor taken reading when cold 10k but reading jumps when up to temp from 4k to open circuit. can anyone advise or is it just a case of replacing the thermistor
Any help much appreciated

 

[gas4you]

For how cheap they are replace it. This is also the overheat thermistor as well.

Should give a range of values depending on system water temp.

Quite a common problem on Ravenheats.

 

[amcal]

Thanks for reply understand your view on replacement, but its the open circuit reading makes me think its worth trying a replacement?

 

[gas4you]

I wouldn't expect this to go open ciruit ever.