Pilot Light
If your pilot light keeps going out or will not ignite at all, this could be down to certain variables, including:
Mains gas supply: always check your mains gas supply by testing your other gas appliances such as your cooker. If these do not work, the problem is with your gas supply, not the boiler, and you will need to contact your gas supplier to rectify the problem.
Low water pressure: check the pressure on the pressure gauge; it should be between one and two bars of atmospheric pressure.
Other problems that you could face with your central heating boiler system is the heating coming on, but perhaps being too hot.