We have an ariston boiler running our central heating system. The heating works fine, it's just that we keep hearing the boiler ignite multiple times when it's on. It often will 'fire up' 2 or 3 times every couple of minutes, which seems odd to me - I would have thought that it would fire up once, and keep burning until the thermostat tells it to turn off? It can also make quite a noise when it fires up, sounds like the valve opening up and is quite loud at times.
Is this normal or is there something wrong with the boiler? I'm concerned that the continual ingition might cause a part to fail prematurely.