Ideal logic heat 15

[Elgordo]

Went to service logic heat 15 today with complaint of L2 showing and having to reset to get it going . Hadn't been serviced in five years from new ... The heat exchanger and siphon were gunged up with aluminium oxide sediment , cleaned thoroughly., cleaned spark and sensor probes ,checked flow and return thermistors, checked gas jet and Venturi feed to fan , Flue is clean .Gas pressure 19mb operating . Rang Ideal in desperation but the guy I spoke to couldn't suggest anything I hadn't already checked . Anyone any ideas ? Thanks in advance .

Sorry , boiler runs for about ten minutes well behaved ,FGA spot on ratio .0006. It then either gets up to heat and restarts or makes a few attempts to and then locks out with L2 displayed . System is filled with water , pump running fine , rads heating .

 

[Roger Welton]

I've had a intermittent fault with a ignition pack before on a logic

 

[Elgordo]

Checked coil pack , it seems ok and has a good spark . Rang Ideal again who said its most likely the sensor probe at fault - will replace tomorrow..

 

[Whyme]

Tell us how ya get on, just incase i come across it.

 

[AllyBongo]

Just out of interest, did you check if the boiler has a good earth?

 

[Elgordo]

Checked all the earths Ally Bongo and all seem good , replaced the flame sensor but didn't make a blind bit of difference ! Going to check flow sensor on Monday , does anyone know voltage/resistance readings for this ?its definitely heat related - no problems starting and running from cold or if left to cool .thanks for replies .