Ideal icos l9 error!

[ICETER]

lads,

looking for a bit of help here,i was looking at an icos for a friend of mine that keeps flashing l9,system is filled correctly and vented and all isolation valves are open,pump seems to be turning fine as i opened it and turned the screw on it and it turned freely,boiler will eventually reset and work for a day or so and l9 flashes again!!!

any help is much appreciated,thanks in advance

 

[tincup]

Hi.

Water pressure low maybe?

 

[ICETER]

water pressure is fine 1.5 bar

 

[kevindgas]

l9 = flue gas overheat
probably the flue sensor is cacked or the boiler has heat exchanger issues either way get an RGI to check it thoroughly paying particular attention to the upper section of the H/E

 

[ICETER]

is there any chance it could be the pump?i checked it and it ran freely but the boiler had been sat up for the summer