While most radiant systems get their hot water from either a tank type water heater or a cast iron boiler my home s heat and domestic hot water dhw are both provided by a single rinnai tankless or on demand water heater.
Can a tankless water heater be used for radiant floor heat.
It s also true that a tankless water heater is smaller and less expensive than a boiler or a furnace.
We plumbed the radiant heating loop of our vacation cabin to the domestic hot water making an open loop system.
Ft lightweight 60 lbs can mount conveniently on a wall vent.
A tankless hot water heater is ideal for this application since there is no water to be kept hot at all times.
We design radiant heating systems to suit the unique characteristics of tankless water heaters.
The rinnai uses considerably less energy than a tank type heater and costs less to install than a boiler with a heat exchanger.
The other consideration is efficiency.
The reasons are outlined below.
Takagi on demand water heaters have many excellent features.
Water heater for radiant heat water heaters are good for radiant floor heating because they maintain a low temperature.
The system with a tankless water heater will also be much more responsive have unlimited supply of hot water and clean water running through the floor heating pipes without sediments and other mineral build ups.
The best tankless water heater for radiant floor heat is the takagi th3 natural gas.
It is the safest choice as well.
You really only need a maximum of 120 f for your floor.
Today tankless heaters are low cost high efficient units that are cheaper to maintain operate.
Dual purpose systems a dual purpose system relies on only one water heater to supply both the hot water requirements for the home and the warm water needed for the radiant floor heat.
You actually have a choice between them as you can use a water heater or tankless for radiant floor heating and not just a boiler.
But standby losses for six months out of every year can add up.
And the cheaper tankless heaters are usually not recommended or warranted by most manufacturers to be used in a radiant heating system and it will probably void your warranty.
All water heaters waste heat energy even when the burner is off and the unit is sitting idle between heating cycles.
However just because you can doesn t mean you should.
It s true that a tankless water heater can easily heat most single family homes.
The down side is two heat sources.
As such we rate it with 5 stars out of 5.
Granted the unit dedicated to heating the floor only wastes heat during the winter months.
The answer is you can.