I know it can be done but what consideration and system changes can be expected?
USA You will need to change the boiler and the controls, and there are several items that need to be installed for a hot water system - pumps, zone valves, expansion tank, pressure regulator, check valves. It can be expensive. You probably can use the existing radiators and pipes, but you will need to remove the air vents and install return piping. I curently use steam and will not change it. A steam system has no moving parts - such as pumps, zone valves or relays to break down. A steam system is quite simple - boil the water, the steam goes to the radiators, the steam condenses into water and flows back to the boiler to start all over again. Blow down the boiler once a week or so, and make sure you have enough water in the boiler. Hot water systems, when working properly, are also easy to use and maintain. But, they have pumps and valves and parts that break down more often than steam systems. If you have trouble getting heat to some areas of the house, have a boiler technician check out your air vents on the radiators. You can control how fast an area warms up by using the air vent.
pipe size doesnt matter. The only difference would be the configuration of the radiators or baseboard units that are being used. Some steam units use the same pipe that supplies the steam for the return water when it condensates. steam will travel above while the return water will travel at the bottom. Also since the presure is different controls would be different. Thats why some boilers are made to do either. But the trim packages are different. I'm curious why you would even consider.
When making steam, the boiler has to heat the water to 212 degrees, when circulating hot water the temperature of the water is under 180 degrees, so there is a saving in fuel consumption. If your boiler is over ten years old, and gas fired don't bother converting to hot water the efficiency on a ten year old boiler is not good.Depending on the size of your home an average gas fired single zone hot water boiler without a coil for domestic water is about $1800.It will cost about that to re trim your old steam boiler. Changing the piping is a whole other story. I've been using plastic or Pex piping. The plastic is a lot cheaper and easier to install. Oil fired equipment is a little more expensive.
it is not that easy,the steam pipes are a lot bigger in diameter to hot water pipes,and the water pressures and controls are different,you would need to change the boiler and the pipes pretty expensive.
