How to Bleed Air from Baseboard Heating System

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Baseboard heating systems are common among homes, offices, and even social halls. When winter knocks, we rely on these devices for warmth. However, baseboard heaters need regular maintenance to operate efficiently.

And today, you’ll learn how to bleed air from baseboard heating system as one of the maintenance practices.

Baseboard heating systems are the most loved heating method by many homeowners. Here are the reasons many people choose them;

  • They are energy efficient
  • They are cheap to purchase and install
  • Easy to use and maintain.
  • They are safe for home use

How to Bleed Air from Baseboard Heating System

There are two types of baseboard heating systems. They are;

  • Convection baseboard heaters
  • Hydronic baseboard heaters

So, which is the best baseboard heating system between the two? You’ll determine after the information below.

  • Convection Baseboard Heaters

Convection baseboard heaters are electrically powered. They have an element that transfers heat to the surrounding air.

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Convection baseboard heaters don’t use any fluid for heating. This article will not discuss much about convection baseboard heaters because they don’t experience airlock.

  • Hydronic Baseboard Heaters

Hydronic baseboard heaters have a boiler that heats the fluid. The devices use non-toxic fluids, with the most common being;

  • Water
  • Oil

When the fluid is heated, it’s directed to the piping by the circulating pump near the boiler. The fluid flows through the metal pipes to the target rooms. Hydronic baseboard heaters are designed with various heating methods. They are either;

  • Natural gas
  • Electricity
  • Propane
  • Oil

There are small metal fins spaced along the surface of the metal pipes. The fins take the heat and transfer it to the surrounding air. When air is heated, it rises to circulate within the room.

Once the fluid loses heat, separate piping leads it back to the boiler for reheating. The hydronic baseboard heaters rely on a thermostat to regulate the temperature within the room.

Read: Baseboard heater low heat output

Benefits of Hydronic Baseboard Heating

To answer which is the best baseboard heating system, I’ll honestly say the hydronic baseboard heating method is the best. Here are the reasons;

  • Efficient – the fluids retain heat for a long time within the pipes after the system is turned off. As such, the house stays warm for an extended period.
  • Energy efficient – the fluid remains hot for a longer period hence regulating temperature. For this reason, energy is saved.
  • Uniform heating – the pipes are installed along the wall or floor. Due to this extended pattern within the room, heat is uniformly distributed.
  • Flexibility – the homeowners have an option to choose between heating fuel. Secondly, they can choose between heat transfer fluids.

Why You Should Bleed Air from Baseboard Heating System

Tiny air bubbles build up as the fluid heats, and with time, they become bigger. Air may get into the system due to various reasons like;

  • Water contains air that expands during heating.
  • Air may get into the pipes during maintenance. For instance, during flushing and refilling the system.

Due to cooling and heating processes within the system, the small air bubbles combine to form one large air bubble. This air bubble settles within the pipes, and due to pressure, it prevents the fluid from flowing. At this stage, it’s referred to as a hydronic airlock.

You may observe several signs to know whether your hydronic baseboard heater has an airlock. Take a look;

  • Your house has started cooling whereas the heater is on.
  • The room heats slowly.
  • There is gurgling noise within the pipes.
  • When you touch the heater’s bottom, it’s hot but cold at the top.

The hydronic airlock is normal, and you’ll need to learn some skills about hot water baseboard heating system maintenance to deal with it. When it gets to this point, you’ll have to bleed air from your heater.

Read: Baseboard heater expansion clips

How to Bleed Air from Hydronic Heating System

Carry out the process below;

Step 1:

Turn on your hydronic baseboard heating system. If it was running, you’re good to proceed. In its operation mode, it will create pressure for easy bleeding.

Step 2:

Open the baseboard heater cover and locate the bleeder valve along the metal pipes. It’s usually at the top of the radiator.

Step 3:

Take a towel, a cup, or a bucket to collect some drops of hot water that fall from the bleeder valve.

Step 4:

Some valves are made of wing nuts, so you can turn them using your fingers. Others have a standard nut that needs a wrench to turn. The third category has slotted head nuts that need a flat head screwdriver to turn.

Once you have the appropriate tool, turn your valve counter-clockwise to open.

Step 5:

You’ll hear a hissing sound as air leaves the pipes and some drops of hot water fall from the bleeder valve. Be careful not to burn your fingers.

Step 6:

Once the hissing sound stops, the system is free of the hydronic airlock. Close the valve by turning it clockwise to avoid excessive water loss.

Read: Baseboard heater fin comb

FAQs on Baseboard Heaters

Is it Normal for Baseboard Heaters to Make Noise?

Baseboard heaters should have minimal noise if well maintained. However, once the noise is extreme, you should troubleshoot the problem. Take a look at some sounds you may experience;

Gurgling or bubbling – the hydronic baseboard heater needs bleeding. It happens due to an airlock.
Banging – there is much pressure in the pipes that they hit each other. You can properly secure the pipes to avoid noise.
Clicking noise – the metal fins are bent or clogged with dust. As a result, they run against each other once they expand or contract.

Can You Put a Couch in front of a Baseboard Heater?

You can place your couch in front of your baseboard heater, provided you leave a space of at least 12 inches for air circulation.

Can Baseboard Heating Cause Fire?

Baseboard heaters are considered the safest home heating method, but they can be a fire hazard if not well maintained. As such, you need to carry out regular maintenance to enhance safety. For example, bleed air from baseboard heating system at the start of every heating session. 

Read: Cheapest heating system to install