Is this adviseable in the long run ...
If you have natural gas available, I would advise it strongly. Oil is costly to maintain, and to fill your tank.Nat. gas has none of the ugly tags attached, excpt installation. This is a recoupurable price tag. You may have to replace your boiler to a new, more efficient model, but in the long run, you will be better off. You will also see an improvement in the value of your house. I don't see a down side.
As Stephen implied, go with a new high efficiency boiler. There are conversion burners available that would allow you to utilize your old boiler, but they are high maintenance and inefficient.
In my area the gas company would install gas conversion burners in oil furnaces. It was cheaper. It is much cleaner. And they require much less service. So that is a big savings. Converting is much cheaper than replacing with a new gas boiler. But a gas boiler is much more efficient than oil, or a converted oil unit. The older gas boilers have a large chamber for the flame generated by oil. And as a result the boiler itself is rather inefficient even if gas is cheaper. Newer ones are better but not a whole lot. That is why your gain is not as much as with a gas boiler. It has to do with the nature of the flame. Oil burners create sort of a ball of flame. They need to do that to get the heavier oil to burn clean. The gas conversion burners have to mimic that flame so they use more gas than a new gas boiler itself would use because the design would be different. But if you don't have gas now there could also be a good savings converting your water heater too if it is separate. I hope info that helps Good Luck
