Boiler or water heaters for infloor radiant heating systems?  That is the question I get so very often.  My preference is to always go with a boiler to heat your radiant floor and use the boiler to heat your indirect water heater as well.  This can give you a very fast recovery rate for your water heater, and these water heaters last longer as well.  I have hooked up many basement systems to a water heater since the water heater is there it is the least expensive method for the homeowner.

If your whole house is being heated through radiant heat then I would use a boiler without any doubt.  Recently I have found a water heater with 90% thermal efficiency.  This water heater has ports on the side of the tank for the radiant heat and takeoffs on the top for domestic heat.  Where I am from you can only use water heaters for radiant heat if the water heater is also heating the domestic water.  This means that if you need to have glycol in the system for a garage or for snowmelt you will have to go with a boiler.

Boiler For Heating Water

Water Heaters For Heating Water