My Heatslave 12/14 oil combi boiler is being very tempremental and has been for some months. It has locked out nearly everyday for too long.(since last service actually)
I've got to know the basic workings(easy replaceable parts-photocell/jet nozzle) fairly well, but I cannot work out why it still locks out.
As the cold weather has drawn in, the boiler is firing up more often but only works some of the time.
When it locks out and it is reset, the boiler doesn't do anything. After a bit of a wait and another try, it will normally fire up as normal and work well until the temp is reached and the boiler turns off automatically.
The same problem is then met when it has to start up again.
Any ideas as to the reason it only starts/fires up when it feels like it?

Simon, October 2008

I would personally try the solenoid on the oil pump ata guess

steve, November 2008

I may have found the solution?
I switched the boiler off and started checking some of the working parts.
Having checked the connections in the control box, I found a loose connection.
So, having corrected this, the boiler (touch wood) has so far been working properly without any lockouts.
Oh how I hope it continues!!

Simon, November 2008