Have ii been ripped off? Central heating stopped working?

Can anyone set my mind at rest? We had a gas leak on our gas fire and called the emergency gas people. They came and disconnected the fire, were very helpful and left the rest of the heating and gas supply connected. However the central heating and hot water didn't come on later that day. I checked the pilot and am 100% sure it was on so we called Homeserve and joined their next day scheme - £320 for a year's cover including that call out. We also turned off the gas at that point just in case.
When the Homeserve man came, he simply relit lit the pilot and the heating started working. Despite my concerns that this wasn't a fix he left without really looking into it.
What i'd like to know is, is it possible that something could have stopped the heating working and then cleared itself when we turned the mains off and on again? Air block or something?
All very frustrating and expensive simply to tun the pilot off and on again.
Any thoughts would be much appreciated.
Thanks