Hydronic Radiant Floor Heating Systems | Pros and Cons | Types | Advantages

Hydronic radiant floor heatingHydronic radiant floor heating

A review of hydronic radiant floor heating systems for homes. Can the radiant heat save you money? Where can it be used? Types, advantages, and installation tips. Compare electric vs. hydronic floor heating.

In this article:

  1. What is the radiant heating
  2. Where it is used
  3. Advantages
  4. Disadvantages
  5. Types
  6. Installation tips
  7. Common problems
  8. Popular brands
  9. Costs

What is the radiant heat?

An example of radiant heat: During the day when the Sun heats the concrete floor or water inside the big barrel, the floor/water will then radiate the heat into the room during the night.

Radiant heating systems use radiant energy emitted from electric coils or tube heaters to heat the floor, wall, or ceiling panels.

How it is used

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(CC BY-SA 3.0), Photo by Chixoy

In radiant floor heating, wires or pipes are embedded into the concrete floor or underneath the plywood floor. If the heating medium is hot water, the PEX tubing is utilized for water transfer as it is producing a stable temperature and higher comfort than any other system.

The PEX tubing is mainly used in hydronic radiant floor heating systems where the boiler or water heater heats up the incoming cold water, and the pump circulates the warm water through the tubes.

Tube heaters, installed underneath the flooring, are conducting the heat to the floor's surface, objects, and people inside the room, rather than heating the air directly.

PEX tubing for hydronic floor heating can be installed in-floor or below-the-floor.

Thin slab or concrete floor radiant heating is an excellent example of in-floor radiant heating, which provides higher comfort inside the home.

The below-the-floor application includes the PEX tubing installed underneath, attached, or stapled to the plywood floor.

Hydronic radiant floor heating systems can be combined with the baseboard and boiler hot water systems and used in additions, remodeled, and in new constructions.

Hydronic floor heating systems are designed for residential and commercial applications, domestic water and home heating, or ice and snow melting on the driveway.


The main advantages of radiant heating are the increased comfort level and the lower energy cost.

You will feel warmer inside the room where the radiant floor heating is installed versus conventional air type systems and at the same temperature (moving hot air also has the cooling effect). Hydronic radiant floor heating systems warm the room entirely; the heat rises from the flooring, through the furniture, people inside the room, to the surrounding air.

Radiant floor heating systems are also more efficient than other types. The system is not using the big blowers to move the hot air, it uses the low-temperature water to heat the floor, object, and people, and the heat can be adjusted from one room to another.

Each room can have its own separate controller, so heating for the unused rooms can be turned off and precisely maintained.

The system also provides a better comfort level when heating the room with a higher ceiling than the systems that heat the air first. In the radiator heating, the heat rises, while the area above the floor surface is colder, making the room air temperature uneven. The baseboard heating system does the perimeter heating only while the center of the room is less comfortable.

Also, radiant heat doesn't dry out the air, and the noise level is lower.

No dirty filters and dust movement is very low, which keeps the air quality inside the room higher and homes healthier.

Heating pipes are out of sight, and they don't interfere with the furniture, which is the case with the radiator or baseboard heating systems.


With radiant floor heating, it takes longer to heat the room and cool the room off.

It requires a higher initial cost when comparing to the traditional systems.

Types of radiant floor heating systems

There are two types of cost-effective radiant heating systems for floors: electric and hydronic radiant floor heating, which use various heat sources. Both systems heat the floor with coils installed in-floor or underneath the floor. For those who prefer do-it-yourself projects, electric is easier, solar and geothermal are more complicated.

Electric floor heating

Electric radiant floor heating systems are more efficient than traditional electric heaters but less than hydronic systems; they are also easier to install and service.

Hydronic floor heating

Hydronic radiant floor heating systems use the liquid as the heating fluid heated by using any known fuels. The most common medium is domestic water, heated by the water heater or boiler. Hot water is moved through the pipes or tubing and then returns to the water heater or boiler for reheating. The water is retained in the system, which has to be replenished periodically, done automatically by the HVAC system.

In some hydronic systems, the temperature in each room is controlled by regulating the hot water flow through each tubing loop. The flow of hot water is control by the system of zoning valves, pumps, and thermostats.

The brain of the hydronic heating system is the control system, consisting of the thermostats, aquastats, and switches.

The heat source used for hydronic radiant floor heating can be a gas and oil-fired boiler, as the most common types, while solar and geothermal radiant heating are getting in popularity. Hydronic radiant floor heating systems are the most popular in colder regions.

A good radiant floor system should last at least 20 years, but it depends on the quality of used materials, heat generator, quality of work...

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Where to install hydronic radiant floor heating system

Basement floors are the perfect place for radiant floor heating systems, as the concrete, either thick or thin slab, is an excellent thermal mass, making the floor a huge radiator. If the thermal mass in the floor is larger, the HVAC system works better. Laminate floors are better than hardwood floors, while the carpet has to be rated appropriately for radiant floor heating and with the proper backing material. Vinyl flooring is not recommended; tile works the best.

Besides the thin slab and thick concrete installation option, you will also find two other popular terms when installing hydronic radiant floor heating systems. They are known as dry systems:

  • Above-floor systems
  • Below-floor systems

The above-floor systems are installed below the finished flooring (hardwood flooring, for example) but above the subflooring. Proper planning is essential for this type of system as this system uses grooved wood panels installed under the finished floor. The floor height is raised, which can cause the problem for doors or plumbing fixtures.

For the below-floor heating system, the above wood panel and second subfloor are not needed, so this system automatically requires less time, labor, and material for the installation.

When the PEX tubing is installed under the plywood floor, it makes the cost of installation lower. You won't find any issues with the weight which is seen with the slab system, but it requires higher temperatures to provide the feeling as the above radiant home heating systems. This system is popular for retrofits.

Common problems with the floor heating systems

  • Tripping circuit breakers. Even the electric radiant heaters do not require lots of voltage; it is important to have the panel big enough to prevent tripping the circuit breaker.
  • Damages to heating cable or mats could result in no heating.
  • Damaged thermostat could lead to no heating, low temperatures, or overheating.
  • Damages to water pipes could lead to leaks.
  • Uneven heat distribution.
  • Problem with the valves and pump could reduce the heating quality due to interrupted water circulation.
  • Air lock problems can block proper water circulation.

Popular brands and manufacturers


The cost of hydronic radiant floor heating systems are much higher than the conventional types of heating, but as it requires low-temperature fluid, the result is lower operating costs (some manufacturers claim that the cost reduction is from 20% to 40%).

For example, radiators use expensive copper tubing, while the radiant floor heating system is inexpensive and easy to install PEX tubing.

The bottom line is that the cost of installing a hydronic radiant floor heating system varies; it depends on the home size, the floor coverings, type of installation, and cost of labor. Based on the info we have found online, a hydronic system for a 1500 sq. ft. home can cost somewhere between $7000 and $13000 (2015).

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Electric or hydronic radiant floor heating systems are gaining popularity as a cost-effective way to heat homes or offices. Yes, it is expensive, but when you take all the advantages into account, such as the unmatched comfort, you will see why it makes sense, either building a new home or remodeling an existing one.

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