Suprima 50L lockout problem

[stucampbell007]

My Suprima 50L frequently goes into lockout mode - flashing red light - when the central heating and hot water is due to come on. When the reset button is pressed, it ALWAYS restarts and the heating and hot water come on as expected.

I have had the PCB replaced with a new one and all the wiring to try and solve the problem. The engineer who did tis replacement has now said it could be the fan unit as the bearings appear to be going.

Could anyone offer any guidance on other possibilities before I spend more money on this? I'm aware of the reputation of these units and am partially resigned to having to replace it completely. My concern is that it may not be the boiler that is at fault as it has never failed to fire up when manually restarted.

Any help greatly appreciated.

Stu.

 

[Dan Robinson]

Could be a gas valve problem as well, but your RGI should know how to test for that.

 

[stucampbell007]

Thanks, Dan.

Does the fan sound like a plausible reason. Something to do with not running fast enough to engage a pressure switch? Seemed strange to me that this would often be the case when it was turned on by the timer but never when reset manually. Surely the speed the fan spins at can't be related to what causes it to spin.

He also said he needed to see the boiler in lockout mode to do any further diagnostics.

Stu.