It's a great system that's needs to be cared for. I would get a certified tech to check the system out and do the needed service. If it's low on boiler fluid the burner won't light. If the check valves are stuck or the circulation pumps aren't working, heated coolant won't get to the registers. It it hasn't been properly winterized it can suffer severe freeze damage. It will cost about $200 to have it serviced but you will also gain a lot of knowledge about the system. Just make sure the tech has experience to do a complete service including cleaning the combustion chamber.