Worcester Cbi 14/19

[Plucky]

Got a problem with above boiler. Customer reports she gets about 45 minutes use befoe it goes to lock out. Shows flame failure fault. Once it is reset works for another 40-45 mins befoe it happens again. Any ideas?

I cant actually find anything immediately wrong with it.

 

[GreenArmy]

Overheat thermostat?

 

[wnjswozo]

check flue,ohms test high limit stats,check for sludge