Put the analyser probe in the flue outside on the air side to make sure seals were ok.. Started doing the fault again... It seems like it doesn't take much of a blockage to cause the fault.
It looks like you were... I should have checked more in depth first time round... I just thought it'd be impossible to be that... Because how could it possible move after 3 years of being ok.
have you tried taking a reading with a combustion analyser on the air side of the flue, on a ideal i think you have to do it from outside, if the air side is contaminated it proves i'm right and this time i want a prize
have you tried putting an analyser on the air side of the flue,
do it just to satisfy my determination that its the flue,
if the o2 doesnt drops below 20.9 on the air intake then you can tell me to shut-up and to forget about the prize
Have you tried monitoring gas pressure at the test point on the isolating valve ? If it's varying in sympathy it would point to either meter regulator or gas valve ..?
Have you tried monitoring gas pressure at the test point on the isolating valve ? If it's varying in sympathy it would point to either meter regulator or gas valve ..?
Have you tried loosening the casing to see if it goes away ? I have found the two spring catches at the base can make the difference between an L2 fault showing and proper running .Is it heating water in this mode? and does it persist when in low fire minimum rate .. hate it when they leave you feeling useless like that !!
Just another thought ... is the heat exchanger flushed clean , they collect a lot of sediment over time and it can lodge and restrict flow of combustion products
Fault still occurs, even with the cover off, heat only boiler but also does it in minimum, fault is definitely on gas side.. I absolutely thoroughly cleaned the heat exchanger, 3-4 jugs of water went through it... Didn't make much of a difference.