What is Hydronic Heating? Comprehensive Guide 2023

Welcome to my blog on hydronic heating with warm greetings. If you are looking for an energy-efficient and comfortable way to heat your home, then you have come to the right place.

With the increasing cost of electricity and gas, homeowners are always looking for cost-effective ways to heat their homes. Hydronic heating is a popular option that provides even heat distribution and can save you money on your energy bills.

One of the biggest pain points of traditional heating systems is uneven heat distribution, resulting in hot and cold spots throughout the home. These systems can also be noisy, require frequent maintenance, and are not very energy-efficient.

Hydronic heating provides a solution to these pain points. This system uses hot water to heat your home, providing even heat distribution and eliminating hot and cold spots. It is also a quiet and energy-efficient option that requires minimal maintenance.

In this blog, we will dive deep into hydronic heating, including how it works, the benefits it provides, and the various types of systems available. We will also discuss the installation process, maintenance requirements, and the cost-effectiveness of this heating option.

What is Hydronic Heating?

In hydronic heating, a liquid (mostly water or glycol) as a heat-transfer medium is moved in pipes for heating. Hydronic heating systems are economical and energy efficient.

The efficiency of this hydronic heating relies on two main parts:

I. Circulation system

II. Heating unit

The circulation system includes pipes, which carry the water through the building. The heating unit is attached to these pipes. There are two different types of heating unit: hydronic and refrigerant.

This type of heating system is very efficient because water is used to transfer heat instead of air. In addition, the heating unit are generally much smaller and lighter than the refrigerant systems.

Components of Hydronic Heating System

A typical hydronic heating system consist of these components:

  1. Heating source (boiler)
  2. Pumping unit for circulation
  3. Expansion tank
  4. Heating load (convectors or radiators)
  5. Piping networks
  6. Air separator
  7. Water fill and make-up system
  8. Control system

Classification of Hydronic Heating

The hydronic heating can be categorized using any combination of the following standards:

  • Operating temperature
  • Pumping and piping arrangement
  • Operating pressure

For an effective and economical hydronic heating system, it is crucial to choose the right boiler(s), pumping systems, pipe configuration, and control system depending on the specific use and the type of facility.

The hydronic system can be classified according to the operating temperature. The steam produced by the boiler(s) must be kept at a safe temperature. The temperature is measured using a thermometer. We must be very careful because a lower temperature can cause serious health problems. The system should also be kept at low pressure. The system pressure should be maintained at a safe level to ensure safe operation.

Operating temperature is a common criterion for categorizing hydronic systems. There are 5 types listed in the ASHRAE Handbook1:

Low-temperature water (LTW)< 250°F
Medium-temperature water (MTW)250°F to 350°F
High-temperature water (HTW)> 350°F
Chilled water (CW)40°F to 55°F
Dual-temperature water (DTW)LTW and CW

ASHRAE Handbook1 – Operating Temperatures

Boiler in Hydronic Heating

A boiler is an essential part of hydronic heating. The boiler should be taken into consideration for a number of reasons. Here are just a few of the reasons:

– Improved efficiency

Water is known to store heat energy significantly more effectively than air. So, not only is your boiler more efficient when it runs, but it also keeps you warmer for longer. Additionally, there is no heat loss from leaking ductwork, which accounts for 30% of energy loss with forced-air furnaces. Boilers guarantee your comfort while helping you save money—the ultimate in comfort.

Boiler with supply pipes in Hydronic System
Boiler with supply pipes in Hydronic System

– Consistency in Heat

Your home will feel consistently warm throughout and sustain the temperature for a longer period of time since boilers use radiant heat to warm things rather than the air. In spite of the fact that boilers raise temperatures more slowly than furnaces, the extra time spent waiting for them to achieve the necessary temperature is worthwhile.

– Improved Air Quality

In order to heat your home, furnaces force air through ductwork. The air you breathe is constantly being polluted by dust, dander, bacteria, and other toxins that can have negative health effects. This issue won’t arise with a boiler because there isn’t any moving air involved.

– Hydronic Heat

Boilers that employ hydronic heat warm your house with hot water instead of air like a furnace does. Boilers heat water, but do not really boil it; instead, they simply distribute it through pipes to radiators, coils, or radiant floor systems as hot liquid or steam. A hydronic heating system has many advantages over a forced-air system, particularly during the winter months.

– Multiple Energy Sources

Boilers can be powered by a number of different fuels, including electricity, wood, natural gas, and oil. It follows that you have a choice in how your system is fuelled. Inform your expert if you have a preference in mind so that they can tailor their suggestions.

The Advantages of Hydronic Heating

A clean, comforting, and energy-efficient method of distributing heat throughout your house is a hydronic heating system. You’ll be astounded by the uniform heating and cooling you get if you’ve never had hydronic heating.

Your home is no longer divided into hot or cold areas. Some of the advantages of a hydronic heating are as under:

– Energy Efficient

Hydronic heating is great in energy efficiency. Air is not particularly good at conducting heat. When it travels through ducts, it can lose energy. It can also leak through gaps or joints in the ducts. It is not very effective at transferring heat throughout a home.

A hydronic system uses hot water rather than heated air. The water doesn’t need to travel anywhere. In fact, it just stays where it is used. That is why you won’t need to turn the heating system on and off as much. It saves up to 40% of your electricity bill.

– Temperature Control through Separate Zones

Hydronic heating systems are far superior to forced air systems. A hydronic heating system can regulate the temperature of several different rooms at the same time, including bathrooms and laundry rooms by creating zones.

If you have a hydronic heating system, you can heat individual rooms using different thermostats. You can use a dual-zone thermostat to adjust the temperature in separate rooms rather than having one thermostat for your entire house.

This can be beneficial for your home because you can have different areas that you want to heat at different temperatures.

– Humidity Levels

One of the biggest problems with traditional heating systems is that they can lead to unbalanced humidity levels in your home. For example, if you have an older home, the cold outside air might make its way into the house.

A hydronic heating system uses water or glycol in a closed system and has no negative impact on the humidity level.

– No Noise System

They can’t be heard in homes that are far from the furnace, and they’re not a problem inside the home where the heat is provided. A radiant heating system uses hot water coils that heat a room rather than electrical elements. The water moves through tubes to radiators placed near the floor and walls.

– Ductless System

With no ductwork, there’s no more worrying about drafts from the HVAC system. No more air leaks due to broken ductwork.

No more dirty, smelly air. Plus, there’s less chance of condensation forming inside the ducting which can freeze up and cause expensive damage. Another benefit is that no more wasted space in the ceiling.

– Environmental Friendly

Hydronic heating is environmentally friendly, as it doesn’t emit any carbon monoxide or other gases into the air. Hydronic heating systems use water or glycol instead of electricity or gas to heat a home or building. They also produce very little noise during operation, unlike the loud noises of traditional systems.

– Durable System

Normal heating systems require repairs more frequently since they feature numerous mechanical and moving elements. Instead, hydronic heating systems are less prone to break down frequently, require little maintenance, and have a longer lifespan.

– The Significance of Hydronic System – Canadian Hydronic Council (CHC)

Choosing hydronic heating has a number of notable benefits as well as some substantial disadvantages.

The Canadian Hydronics Council (CHC), which is on the Positive side of the issue, has created an infographic that succinctly outlines the main advantages:

Benefits of Hydronic System - Canadian Hydronic Council (CHC)
Benefits of Hydronic System – Canadian Hydronic Council (CHC)

Disadvantages of Hydronic System

Following are some of the disadvantages of hydronic HVAC system

– Longer Heating Time

It takes longer to heat an area/zone because heated liquid must pass through the entire system. It takes longer to heat an area/zone because heated liquid must pass through the entire system.

– More Space is Required for Baseboard Convectors

The necessity for more area close to convectors may cause difficulty in setting up your room like making it difficult to place the furniture. This can cause a disadvantage in-room presentation.

– Expansion Tank Regular Maintenance

Expansion tanks require regular maintenance in a hydronic heating system. They need to be drained occasionally to maintain efficient operation.

– Higher Installation Cost

The operational cost of a hydronic HVAC system is lower but the upfront installation cost including the materials and labor for a hydronic system is higher.

– No Ductwork for AC

A hydronic heating system is not a wise choice if you reside in a place where central air conditioning is necessary. Additionally, it is highly expensive to build two separate heating and cooling systems.

The Cost of Hydronic Heating System

It is best to examine these specifics with a specialist to evaluate whether Hydronic heating is the perfect choice for your needs. There are many different options when you think about installing a hydronic heating system.

The first thing you need to consider is the location of the hydronic heater. You should know the dimensions of the room that you are going to install the system and how it will be used.

You should be sure that the room will fit the unit properly. The cost will depend on how big the system is, how many zones are needed, and how much it will heat the room.

You should know the number of rooms that you will have in your building and how many people will use it. When you plan a hydronic heating system, you should know how long it will last.

The cost of a hydronic heating system depends on the type of materials that you use. You can check the cost of the installation and the cost of a new installation. It depends on the type of system that you install.

Recommissioning of Hydronic System

Hydronics systems are quite complex, which is why they often need to be repaired or replaced. We frequently discover that a thorough system recommissioning can extend the lifespan of a problematic Hydronics installation for many more years at a fraction of the expense of a complete overhaul in older buildings.

It’s similar to pressing the reset button to recommission something. Most of the time, maintenance places less emphasis on the operation of the system as a whole and more emphasis on the repair or replacement of individual components.

A technician will first do an efficiency assessment prior to beginning the work, looking at things like

  • Pressure Level of Gas
  • Burners Cleaning
  • Electrical Part
  • The efficiency of the Pump
  • Volume of Air

You can’t just replace parts of the hydronic system. It takes time and money. So when something is damaged, the best thing to do is to fix it. It’s best to repair the system instead of replacing it.

Sometimes you can buy new parts. These parts are easy to install. A plumber can help you to install them. Make sure to hire someone who knows how to install those parts. It’s very important to fix the system correctly.

You should check the system and the parts of the system once every year. If you do that, you can make sure that the system works properly. It would help if you also cleaned the water pipe. Make sure that you clean the pipe properly. You can hire a professional to do the cleaning.

Cleaning the pipes properly is very important. Cleaning it will also help you to make sure that the system is working properly. This is the best way to get rid of the bad smell. It can also help you to keep your house nice.

What is the Difference between Hydronic Heating and Hydronic Cooling?

Hydronic heating and hydronic cooling are both types of HVAC systems that use water to heat or cool a building. The main difference between them is the direction of the heat transfer.

Hydronic heating uses hot water circulating through pipes to radiate heat throughout a building. The heat is transferred from the hot water to the cooler air in the building, warming the space.

Hydronic cooling, on the other hand, uses chilled water to cool a building. The chilled water circulates through pipes and absorbs heat from the warmer air in the building, cooling the space.

Both systems can be very efficient and provide a comfortable indoor climate. However, the installation and maintenance costs can be higher for hydronic systems compared to traditional forced-air systems.


In conclusion, hydronic heating is a highly efficient and comfortable way to heat homes and buildings. By using hot water flowing through pipes installed in the floors, walls or ceilings, it provides a consistent and even heat throughout the space. Hydronic heating systems are also versatile and can be integrated with renewable energy sources such as solar and geothermal, making them an environmentally friendly option.

While installation costs may be higher compared to traditional heating systems, the long-term energy savings and improved comfort make hydronic heating a worthwhile investment. With advancements in technology, hydronic heating systems are becoming more accessible and customizable, making it an attractive option for both residential and commercial properties.


Q: Does hydronic heating use a lot of water?

A: No, hydronic heating does not use a lot of water. The water is circulated through pipes and is continuously reused, making it a very efficient heating option.

Q: Is hydronic heating gas or electric?

A: Hydronic heating can be both gas or electric, depending on the type of boiler used. Gas boilers are more common, but electric boilers are also available for smaller installations.

Q: What liquid is used in hydronic heating?

A: Water is typically used in hydronic heating systems to transfer heat throughout the home. In some cases, a mixture of water and antifreeze is used to prevent freezing during cold weather.

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