Brain fart?

[Chris F]

Doing a cp12. The boiler is a worcester greenstar 25si combi
Standing pressure is 23mbar
Working pressure at meter in service mode is 18mbar
Pressure at inlet on the gv is 22mbar
Fire up the boiler it drops Down to 4mbar
Ratio readings are fine 9.9 co2 and burning 24.63kw
Mi says at that test point in service mode it should be 16.5 minimum.
Am I missing something? I feel like I'm losing the plot, never had one drop to 4

Cheers lads

 

[Chris F]

Never mind 🙂 there was some cack in the valve.

 

[Leo21]

Had the same on a Vaillant, almost lost the will to live.

 

[ed209]

Meter regulator?

 

[moogwai]

Had that a couple of times.... Once on a duotec he a which went to lock out and once on a 30si....both times resulted in a new gas main put in.