ideal responce boiler?

we have had our boiler for 5 years, it is an idial responce combination boiler 12O .we have rebuilt our home, and there is more radiators, today my husband had to move a pipe, the radiator got warm then went off, the light is still on, but no noise is coming from the boiler, could this be the pump, it has been leaking a little, and it looks like the pump inside the boiler has some rust. could it be the pump.