Problem with hot water

[gingergoose]

Hi.
I’ve got Biasi Combi Boiler Riva Plus HE M296.28SM/C.
The heating seems to work fine. There is no problem with hot water when the central heating is on. But with the central heating switched off, when I open the tap to get hot water, the boiler ignites and the flame is on for a few seconds and then it goes off. This repeats several times then the boiler fault code appears - left lamp on (green), middle lamp flashing red and the right lamp flashing green - which according to the manual is „safety thermostat lock out” fault. The last thing to mention is that every now and then (after many tries) the hot water goes on even with the central heating off, but that's very rare and requires re-seting locked out boiler.
Could anyone advise me what problem with the boiler might that be? Thanks.

 

[gasbanni]

Hi,
It's probably a blocked secondary heat exchanger.

This can be cleaned our by a gas fitter that knows what he's doing.

It's easy to tell if you were stood in front of it and the fault could be determined straight away.

Four new washers half ab hours work and it should be up and running !