Grant Vortex Combi 26e Problem.

[Daddles]

The boiler has been firing, stopping, firing, stopping but still doing is job of heating. Then one morning, pressure was zero. I typed it up to pressure and all was fine. Then in the evening it had stopped working completely. Pressure was still correct. The red power light was pulsing. I pressed overheat reset - nothing. I checked power to terminals - mains coming in but not getting anywhere else.
Can anyone help?
Thanks.

 

[oilhead]

Follow the fault finding chart in your manual. Does it not work on either heating or hot water? Have you got full voltage?

 

[snb]

My guess is when it ran low on pressure it has got some air in the top of the main exchanger. You then topped it up but when it reached temp it has activated the overheat and it won’t reset until cools down. But with air at the top it won’t cool down for a lot longer. There should be a couple of bleed valves in the top of the boiler