Hi, We're having a few problems with our Biasi Prisma 28SE combi boiler.
The DHW is only working when the CH on The lock out red light does not come on. It sounds like the initial start-up sequence starts but then nothing. If the CH is already on it diverts to DHW and no problem.
That said, if the CH has been on for some time and the prog room thermostat temp is reached and the CH goes off the DHW will work
If I switch off the CH by lowering the room thermostat and then try the DHW and it doesn't come and immediately try the CH it will also not come on. If I then wait for a few a minutes and re-try the CH by increasing the room thermostat.
In all cases where either the DHW or CH are not starting the red lock out light is not showing.
Due to the intermittent nature of the fault two engineer visits have failed to diagnose the problem.
Aany help much appreciated!!
thanks
Paul
The DHW is only working when the CH on The lock out red light does not come on. It sounds like the initial start-up sequence starts but then nothing. If the CH is already on it diverts to DHW and no problem.
That said, if the CH has been on for some time and the prog room thermostat temp is reached and the CH goes off the DHW will work
If I switch off the CH by lowering the room thermostat and then try the DHW and it doesn't come and immediately try the CH it will also not come on. If I then wait for a few a minutes and re-try the CH by increasing the room thermostat.
In all cases where either the DHW or CH are not starting the red lock out light is not showing.
Due to the intermittent nature of the fault two engineer visits have failed to diagnose the problem.
Aany help much appreciated!!
thanks
Paul