Ideal F/L codes

[corrigr]

Grateful for any help/advice

i first got a F/L code on this boiler in the cold weather and called out a good plumber who i had used before. the cold had caused a frozen pipe which was remedied. Since then at roughly weekly intervals the boiler has cut out showing the L/F code and usually preceded by loud noise when the boiler is trying to light itself to reach the thermostat temperature. the plumber is mystified as he has checked the system there are no blockages/drainage faults so we are both at a loss - any ideas/

Thanks

 

[screech]

Get someone that's gas safe registered. It sounds like a nice easy fix of delayed ignition but can only be rectified by someone gas safe registered due to where the fault is