We are independent & ad-supported. We may earn a commission for purchases made through our links.
Advertiser Disclosure
Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.
How We Make Money
We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently of our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.

What are Hydronic Baseboard Heaters?

By C. Wilborn
Updated May 16, 2024
Our promise to you
HomeQuestionsAnswered is dedicated to creating trustworthy, high-quality content that always prioritizes transparency, integrity, and inclusivity above all else. Our ensure that our content creation and review process includes rigorous fact-checking, evidence-based, and continual updates to ensure accuracy and reliability.

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

Editorial Standards

At HomeQuestionsAnswered, we are committed to creating content that you can trust. Our editorial process is designed to ensure that every piece of content we publish is accurate, reliable, and informative.

Our team of experienced writers and editors follows a strict set of guidelines to ensure the highest quality content. We conduct thorough research, fact-check all information, and rely on credible sources to back up our claims. Our content is reviewed by subject-matter experts to ensure accuracy and clarity.

We believe in transparency and maintain editorial independence from our advertisers. Our team does not receive direct compensation from advertisers, allowing us to create unbiased content that prioritizes your interests.

Hydronic baseboard heaters use heated water or another liquid to control the temperature in a room or area. Positioned along the base of a wall, these heaters draw in cool air at the base, which is heated and pushed out of the top of the heater to warm the room. Low external operating temperatures allow them to be installed flush against a wall or baseboard without damaging the structure.

The technology behind hydronic heaters has been used since the 1940s and has evolved from cast iron radiators. Modern heaters of this type are lighter and easier to install than their predecessors. In a built-in system, water is piped from a central boiler to the baseboard heaters, with a return pipe channeling cooled water back to the boiler for reuse. Heaters can be separated into zones, with thermostats for each area, allowing for better control over the temperature. A range of baseboard heater covers are available to coordinate with a room's decor without obstructing their heat.

This type of system is permanent. These heating systems are usually added when a house is being built because the plumbing involved makes it difficult to add to an already existing structure.

Electric hydronic baseboard heaters have a heating element and liquid sealed within the heater, so they do not have to be linked into the household plumbing. These heaters are wired into the household power supply, and most can be wired to a remote thermostat. They are easier to install in an existing structure than one linked to household plumbing, but the wiring required does not allow for the easy relocation of a heater.

Portable electric hydronic baseboard heaters are also available, and they can plug into any standard household outlet. They are usually smaller than those wired into the household power, and heat a smaller space. Temperature is controlled by a thermostat directly on the unit.

Hydronic baseboard heaters have a number of advantages. They are usually quiet and efficient. Being closed systems, these types of heaters don't require the owner to periodically add liquid. Additionally, hydronic heating does not dry out the air or spread dust or allergens.

Along with these advantages, however, there are some potential disadvantages. Due to their location on the baseboard, the heaters take up wall space, and should not be blocked by furniture, curtains, or other obstructions. They also heat a space relatively slowly, and unlike forced air heating systems that can be linked to an air conditioning system, hydronic heaters are necessarily separate from a cooling counterpart.

HomeQuestionsAnswered is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Discussion Comments
By anon992324 — On Aug 30, 2015

Re: fitness234's original post - the fluid/oil used in electric hydronic baseboard heaters are able to store a large amount of heat within a small volume, without boiling. The oil acts as a heat buffer, similar to an electric capacitor, storing energy for a period of time. The benefit is more even heating of the space, resulting in fewer on/off cycles compared to electric (direct air) convection heaters.

Because the heated surface area of a hydronic heater is typically larger than that of an electric (direct air) convection heater, its surface temperature is lower and safer for children and pets, and less likely to damage/ignite nearby materials.

As for efficiency, all convection heaters, both direct air and hydronic, are 100 percent efficient. The extra time required for a hydronic heater to reach peak temperature is recuperated when the unit is turned off. The direct air unit will cool down faster, while the hydronic will continue heating for sustained period.

We opted for an electric hydronic baseboard heater, since it will go in a nursery. We wanted a heater that is safe, quiet and requires fewer on/off cycles in operation. Having used oil-filled electric heaters for years without any leaks, we are not concerned about reliability issues.

By anon989611 — On Mar 14, 2015

Our house was built in the 50s with a gas powered water fed boiler for the baseboard heaters. My gas bill during the winter was $350.00 until the boiler broke. A new one would cost $3,000 or more before labor, so I used radiator space heaters. My cost to heat the house dropped by $200 for the following winter because I'm able to control the heat in each room.

By anon987479 — On Feb 03, 2015

"Hydronic heaters do not dry out the air."

Not true. When air heats up, its relative humidity drops, making it able to evaporate and hold more water. This is why it's often necessary to use a humidifier in winter.

Now, hydronic heaters may seem to prevent the air from drying out, but perhaps it's because they heat the air slower, allowing residual moisture in the walls and furniture to travel back into the air. Also, people create moisture through sweat and breathing. This may account for it.

But scientifically speaking, when air heats up, it gets dry. Period.

By anon342863 — On Jul 24, 2013

Go with a ductless heat pump, not baseboards.

By anon338190 — On Jun 11, 2013

Those advocating for electric heating systems have probably never paid the hydro bill. Natural gas is cheaper than electricity for heating this way.

By anon134105 — On Dec 13, 2010

Those of us, however, who derive our electricity from water or wind turbines would find inefficiency (and increased asthma rates) in the gas/oil to electric conversion. Oil doesn't ship itself from Saudi Arabia, process itself into gas and deliver itself to the end-user. When carbon-based energy is priced in the US as it is in the rest of the world, electric heat will make sense to more and more people.

Additionally, electricity prices are controlled by the CPSC, one of those evil gub-mint organizations that protects citizens from big business.

Petroleum products (as we've seen) are subject to wild fluctuations when the private markets are manipulated. Remember $4+ a gallon gas, United States of Amnesia citizens?

By anon129986 — On Nov 26, 2010

Basic physics should also tell you that there are numerous steps involved in converting gas or oil to electricity in the power plant. In addition to this your looking at some electrical transmission losses.

High efficiency gas appliances easily produce heat at over 80 percent efficiency, while power plants are lucky to produce electricity at over 35 percent efficiency.

Think about the big picture. there is a reason why electricity prices are higher than gas for heating applications.

By fitness234 — On Nov 04, 2010

Living in the Northwest part of the United States, I have come to appreciate the value of baseboard heaters and other sources of warmth that are necessary in the cold, wet winters up here. I have found that I like the efficiency of electric resistance heaters however. Instead of using a fluid of water or oil, these types of heaters use direct electrical current passed through metal to heat the air directly.

Basic physics would tell me that because of the less steps of energy transfer that must happed until the air of a room is heated that these resistive electric radiators are far more efficient. Since they don't have to first heat a fluid that then heats metal that heats the air, there are fewer parts to break down as well. There is no possibility of a fluid leak since there are no fluids in these baseboard heaters.

While hot water baseboard heater systems that used a central broiler might have been the most effective means a century ago, there is no doubt that running a simple electrical line during construction is much simpler then running a full and separate pluming system to heat your house. I would recommend to anyone who has the option of either that they select the direct air heating type of heaters for their home and the loved ones that they care about.

HomeQuestionsAnswered, in your inbox

Our latest articles, guides, and more, delivered daily.

HomeQuestionsAnswered, in your inbox

Our latest articles, guides, and more, delivered daily.