How can I tell if a boiler is a hot water or steam boiler?For example:Is the piping different? What will the temp gauges say for each? Are the fittings different? Will there be different clues at the AHU coils? What are the clues.
If you have a steam boiler there will be a glass tube [sight glass] on the side of the boiler that is there to check the water level in the boiler.The water will be approximately half way up the tube.A steam boiler requires space above the water for the steam.A water boiler[hydronic heater] will not have this sight glass.There will also be a circulator on a hydronic boiler to move the water around,however a steam boiler may have a circulator added on to the lower piping to utilize the hot water in the bottom of the boiler instead of steam for a heat zone.This is rare but I have seen it done so the sight glass will be the best clue.Many of the controls will also be different but it would be difficult to explain all the differences here.
I'm here to tell you that if you have a water boiler you have a steam heat Water+heat (boil ) = steam