Ravenheat csi 85 et lights up then goes off

[proelitegas]

Hi,

above boiler is lighting up on both dhw and ch and burner lighht at full flame then after a few seconds goes off.. Now I know the cure is chuck it in the skip but customer won't have that lol I have checked both Ntc sensors which are ok and suspicion goes to overheat stat. Is there anyone who can assist on diagnosing this issue I'm aware from previous posts that blocked hex could be a issue but all advice would be appreciated. Thanx in advance.

 

[Billy Bob Bob]

Hi,

above boiler is lighting up on both dhw and ch and burner lighht at full flame then after a few seconds goes off.. Now I know the cure is chuck it in the skip but customer won't have that lol I have checked both Ntc sensors which are ok and suspicion goes to overheat stat. Is there anyone who can assist on diagnosing this issue I'm aware from previous posts that blocked hex could be a issue but all advice would be appreciated. Thanx in advance.

is it detecting flame rectification? does it light and sparking stop? its quite common on this boiler for the insulation on the detection lead to fail right on the spade end of the probe