How To Replace Hot Water Baseboard Heaters

Replacing old or damaged hot water baseboard heaters (HWBH) can help improve the efficiency and performance of your home's hydronic heating system. While a project of this scale requires proper planning and care, upgrading your HWBH is an attainable DIY task for many homeowners.

First, let's quickly go over what HWBH are and why you may want to replace them.

What Are Hot Water Baseboard Heaters?

HWBH are a type of convection heating system commonly found in homes. They consist of long metal enclosures that mount along walls or underneath windows. Inside each enclosure is a copper pipe containing hot water from your home's gas or oil-fired boiler. As the hot water circulates through the pipe, the aluminum fins attached to the exterior help dissipate the heat into the room mainly through natural air circulation.

Compared to radiators, HWBH distribute heat through the principle of convection rather than radiation. Good airflow around the units helps transfer warmth efficiently around the room. Proper installation along exterior walls and under windows takes advantage of natural air currents in the space. HWBH require careful heat load calculations to determine the required length to heat each room based on its size and exposure.

When to Consider Replacing

• To increase energy efficiency - Newer HWBH models regulate temperatures better.
• Corrosion or damage - Leaking or deteriorating units need replacement.
• Improve room comfort - Upgrade for more responsive temperature control.
• Boiler conversion - If switching boiler fuel source, new HWBH may be needed.
• Aesthetic upgrade - Improve appearance with new enclosures and covers.

Preparing for Hot Water Baseboard Heater Replacement

Taking the proper precautions upfront will ensure safe removal of the old HWBH and simplify installing the new one.

Turn Off Water and Power Supply

Start by shutting off the water feed to the boiler and turning off power to the unit. This prevents accidental scalding and electrical hazards while working on the heating system. Remember, HWBH operate at high water temperatures - precautions are essential.

Drain Existing Baseboard Heater System

With the water feed off, open the drain valve on the boiler to empty water from the hydronic loop. This lowers the weight of old baseboard units for removal and lets you inspect the existing piping. Ensure drain pans are placed to catch any drips.

Remove Cover Panels

Take off any removable access panels or covers exposing the HWBH piping and fins. This allows you to access connection points and mounting hardware. With panels removed, check for signs of leakage at fittings or other damage.

Removing the Old Hot Water Baseboard Heater

With the prep work complete, it's time to remove the old HWBH. This involves disconnecting the water lines, removing mounting hardware, and lifting the unit off the wall. Safety gear like gloves and eye protection are recommended.

Disconnect the Water Lines

At the union fittings connecting the HWBH to the hydronic piping, loosen the couplings and detach the water lines. Have a pan ready to catch any water still in the pipes. Make note of the layout to duplicate when installing the new one.

Unscrew Mounting Brackets

The HWBH likely has mounting brackets screwed into the wall studs or surface behind it. Remove any screws securing the unit. This releases it from the wall.

Lift Old Heater Off Wall

With the water lines disconnected and mounting hardware removed, carefully lift the old HWBH unit off the wall. The copper piping inside can make it heavy, so use proper lifting techniques or get a helper. Set it aside for disposal.

Installing the New Hot Water Baseboard Heater

With the old unit out of the way, it's time to install the new HWBH. This involves carefully mounting it, reconnecting the supply lines, and bleeding any trapped air out of the system.

Position and Mount New Heater

Place the new HWBH in the same position against the wall or under the window. Reuse existing mounting holes if possible. Attach new mounting brackets securely into wall studs or use appropriate anchors for your wall type. Ensure the unit is level and properly supported.

Reconnect Water Supply Lines

Attach the water supply lines to the new HWBH using union fittings and pipe sealant to prevent leaks. Follow the inlet and outlet configuration used on the old unit. Use new piping if the existing lines are corroded or damaged. Ensure a slight downward pitch for proper drainage.

Bleed Air from Lines

Before refilling the system, air pockets need to be bled out. Open the air relief valve at the end of each HWBH while refilling until water flows out smoothly. This purges trapped air which can cause noise and ineffective heating.

Reattach Cover Panels

With the new unit piped and secured, replace any access panels and covers. This completes the physical installation. Now it's time to get your upgraded HWBH operating properly.

Completing the Hot Water Baseboard Heater Replacement

With the new unit installed, there are a few final steps to complete for smooth and efficient operation.

Confirm Proper Operation

Turn the boiler and water supply back on and check for leaks at connections. Verify the HWBH heats up by feeling along the bottom. Make any piping tweaks needed.

Set Thermostat

Program or adjust the thermostat controlling the new HWBH. Set to your desired room temperature and test it heats up. Consult manufacturer guidelines for any specific settings.

Finally, properly dispose or recycle the old HWBH according to local regulations. Many metal recycling centers accept hydronic radiators and piping.

Upgrading old or damaged hot water baseboard heating units is a manageable project for DIYers with some plumbing know-how.Focus on safety and precision when removing old HWBH and installing new replacement units. With careful planning and preparation, you can improve the efficiency and longevity of your home's hydronic heating system.