You have two separate and unconnected problems to consider:
1. Do you have a pressure problem? If so, is it in the boiler or the system? Pressure up your system cold to 1.25 bar. Make sure it has stabilised, then turn the isolating valves on the boiler. Leave for an hour or so and check the gauge. If it has fallen, you have a boiler problem. Open up the isolating valves and see what happens to the gauge. If it falls, you have a leak in the heating circuit. If before opening the valves you have lost pressure, and your system is sound, you should notice the pressure gauge rise.
2. Burner lockout is indicative of flame failure and is caused by lack of fuel, faulty flame sensing with a faulty cell or obstructed view, or a faulty control unit.
Treat each problem separately. Trying to correct them together will be distracting.
1. Do you have a pressure problem? If so, is it in the boiler or the system? Pressure up your system cold to 1.25 bar. Make sure it has stabilised, then turn the isolating valves on the boiler. Leave for an hour or so and check the gauge. If it has fallen, you have a boiler problem. Open up the isolating valves and see what happens to the gauge. If it falls, you have a leak in the heating circuit. If before opening the valves you have lost pressure, and your system is sound, you should notice the pressure gauge rise.
2. Burner lockout is indicative of flame failure and is caused by lack of fuel, faulty flame sensing with a faulty cell or obstructed view, or a faulty control unit.
Treat each problem separately. Trying to correct them together will be distracting.