Baseboard heating systems are a popular choice for many homes due to their efficiency and effectiveness in providing warmth during cold winter months.

However, over time, sediment and debris can accumulate in the system, which can affect its efficiency.

To ensure that your baseboard heater system runs at maximum efficiency, it’s important to know how to drain it properly.

How To Drain & Refill The Water On Baseboard Heating System?

Step 1: Turn off the power to the system

The first step to draining your baseboard heater system is to turn off the power. This will ensure your safety during the process. If your system has an on/off switch, use it to turn off the power. If not, turn off the power supply at the breaker or fuse panel.

Step 2: Locate the drain valve

The next step is to locate the drain valve. The valve is usually located near the bottom of the boiler or on the pipes that connect the boiler to the baseboards. Look for a simple faucet with garden hose threads on it.

Step 3: Place a bucket or container under the drain valve to catch the water

Before opening the drain valve, place a bucket or container under it to catch the water that will flow out. This will prevent a mess and make the process easier.

Step 4: Open the drain valve and allow the water to flow out

Once you have a container in place, open the drain valve by turning the knob counterclockwise. This will allow the water to flow out of the system. It’s important to be patient during this step, as it may take some time for all of the water to drain out.

To drain your baseboard heater system, you need to connect a hose to the drain valve, which is located at the lowest point on the boiler. The drain valve should have standard 3/4-inch male hose threads, which you can screw on a garden hose.

If it doesn’t, you can secure a length of polypropylene tubing to the outlet with a hose clamp.

Interestingly, some professionals still refer to the standard worm-drive hose clamp as a Jubilee clip, which was the name given by its inventor.

Once you have connected the hose, run it to a suitable drainage location, such as the floor drain in the basement (if there is one) or a storm drain outside.

Step 5: Once the water has stopped flowing, close the drain valve

Once all of the water has drained out, close the drain valve by turning the knob clockwise. This will ensure that no water leaks out of the system.

Draining Water Off Baseboard Heating System

The draining and refilling of your baseboard heating system can be agitating and a little time-consuming. Be patient. It’s worth it!

  1. Turn down the thermostat in your home and switch off the power supply to the boiler. If your boiler has an on/off switch, use it to switch off the power. If not, switch off the power supply at the breaker or fuse panel. Allow the system to cool for at least two hours.
  2. Locate the water inlet pipe that connects the boiler to the house water supply pipes. Turn the valve on the supply pipe clockwise to turn it off. Find the boiler drain, which is a simple faucet with garden hose threads located near the bottom of the boiler. Connect a garden hose to the boiler drain and run the hose to a floor drain. Turn on the boiler drain by turning the knob counterclockwise. Water should begin to gurgle out of the hose.
  3. Locate the baseboard heater that is farthest away from the boiler. On one end of the baseboard, there is a small bleeder valve. Open the bleeder valve by rotating the screw on the top counterclockwise using a flat-head or Phillips screwdriver. Open the valve until air is heard being drawn in as the heating system drains.
  4. Check the drain hose to make sure that water is flowing slowly. Once the water stops flowing, turn off the boiler drain and disconnect the garden hose. Check to see if the expansion tank, a small barrel-shaped tank located near the boiler, has a drain on it. If it does, open the drain valve counterclockwise and drain the remaining gallon of water into a bucket. Close the drain valve by turning it clockwise.
  5. Close the bleeder valve on the baseboard that was opened earlier by turning the top screw clockwise until it is snugly closed, but not over-tightened. Turn on the water supply to the boiler. Find the baseboard nearest to the boiler and open the bleeder valve on it. You should hear a hissing sound as air is expelled from the system. Hold a small dish or towel near the valve to catch any water that may spill. Once the air is purged and water squirts out of the valve freely, close the valve and wipe up any spilled water. Repeat this process with each baseboard, starting with the nearest to the boiler and ending at the furthest away.
  6. Turn the power supply back on to start the boiler. Turn up the thermostat until the heating system starts up. Check to see if the baseboards become warm. If they do not, repeat the air bleeding process on the baseboards that are cold.

Refilling Water On Baseboard Heating System

Typically, you’ll need to drain and refill your radiators if you wish to move or replace them – or if you are treating corrosion. First you’ll need to empty out the water, so switch off the central heating and the water supply to stop the system re-filling. Do this by turning off the water at the main stop valve.

Step 1: Turn off the power to the system

Before you begin to refill your system, turn off the power to the system to ensure your safety during the process.

Step 2: Locate the fill valve

The fill valve is usually located near the boiler or on the pipes that connect the boiler to the baseboards. Look for a valve that is similar to the drain valve but is used to fill the system with water.

Step 3: Connect a hose to the fill valve and place the other end in a nearby sink or drain

Attach a hose to the fill valve and place the other end of the hose in a nearby sink or drain. This will prevent water from spilling onto the floor and make the process easier.

Step 4: Open the fill valve and allow water to flow into the system

With the hose in place, open the fill valve by turning the knob counterclockwise. This will allow water to flow into the system. Be patient during this step, as it may take some time for the system to fill.

Step 5: Watch the pressure gauge and continue filling until it reaches the recommended level

As you fill the system with water, keep an eye on the pressure gauge. The pressure gauge will tell you when the system has been filled to the recommended level. Keep filling until the pressure gauge reads the recommended level.

Step 6: Once the pressure gauge is at the recommended level, close the fill valve and remove the hose

Once the pressure gauge has reached the recommended level, close the fill valve by turning the knob clockwise. This will prevent water from continuing to flow into the system. After you have closed the valve, remove the hose from the fill valve and put it away.

Remember to keep an eye on the pressure gauge and stop filling once it reaches the recommended level.

What If Air Is Trapped In The System After Refilling?

If air becomes trapped in the system after refilling, it can cause the baseboards to be cold or for the pressure gauge to fluctuate. To solve this issue, you can perform the following steps:

Step 1: Turn off the power to the system

Step 2: Locate the bleeder valve on the baseboard that is farthest away from the boiler

Step 3: Open the bleeder valve by rotating the screw counterclockwise using a flat-head or Phillips screwdriver

Step 4: Allow the air to escape from the system until water begins to flow out of the valve

Step 5: Close the valve by turning the screw clockwise until it is snugly closed, but not over-tightened

Step 6: Repeat this process with each baseboard, starting with the baseboard farthest from the boiler and working your way towards the boiler.

Performing these steps will allow any trapped air to escape from the system and restore proper heating to the baseboards.