Boiler has mains power and pressure guage at 1.75 with low pressure light red on. Boiler does not start , timing clock shows no indicatios at all and internal fuses (2) OK. Pressure switch and suction connections seem OK. Heating Engineer called in but couldn't work out the problem and got called away in emergency. Any clues please?

james B, October 2012

Is fan running ,is pump running still not working than it's water pressure switch right on right hand return pipe you have to empty system to clean undo it's hard to undo but spray WD40

ltd, October 2012