Installing radiators can be an important part of a home renovation project. Therefore, it's essential to get it right to ensure optimal performance and efficiency. During radiator installation, a common question that comes up is whether it's okay to install a radiator upside down or backwards. Let's learn more about this topic and find out the dos and don'ts of radiator installation.

Understanding Radiator Installation Instructions

Before we address the question of whether a radiator can be installed upside down, let's first emphasise the importance of following manufacturer installation instructions. These instructions typically provide detailed guidance on how to install the radiator correctly, including orientation, positioning, and connection to the heating system.

How to Install a Radiator Correctly?

Installing a radiator correctly is vital for ensuring efficient heating in your home. Mastering the art of radiator installation can save you time, money, and potential headaches down the line. Here's how you can install a radiator correctly.

Step 1: Choose the Right Location

Before you start installation, carefully choose the location for your radiator. Ideally, it should be placed on an exterior wall to maximise heat distribution. Additionally, ensure there's enough space around the radiator for proper airflow. Avoid placing it behind furniture or curtains that could obstruct heat circulation.

Step 2: Gather Your Tools and Materials

You'll need a few tools and materials to complete the installation:

  • Radiator
  • Mounting brackets
  • Thermostatic radiator valve (TRV)
  • Pipe wrench
  • Adjustable spanner
  • Spirit level
  • Pipe cutter
  • Pipe fittings and connectors
  • Pipe thread sealant

Make sure you have everything you need before you begin.

Step 3: Prepare the Pipes

Before installing the radiator, prepare the pipes for connection. Measure and cut the pipes to the appropriate length using a pipe cutter. Use a pipe deburrer to remove any rough edges. Clean the pipe ends thoroughly to ensure a proper seal.

Step 4: Install Mounting Brackets

Attach the mounting brackets to the wall at the desired height for the radiator. Use a spirit level to ensure they're level. Make sure the brackets are securely fixed to the wall to support the weight of the radiator.

Step 5: Connect the Pipes

Next, connect the pipes to the radiator using appropriate fittings and connectors. Use a pipe wrench and adjustable spanner to tighten the connections securely. Apply pipe thread sealant to ensure a watertight seal.

Step 6: Install the Thermostatic Radiator Valve 

If your radiator requires a thermostatic radiator valve (TRV), install it according to the manufacturer's instructions. The TRV controls the temperature of the radiator and helps regulate heating in the room.

Step 7: Bleed the Radiator

Once the radiator is installed and connected to the heating system, it's essential to bleed any trapped air from the system. Use a radiator key to open the bleed valve and release any air until water begins to flow smoothly.

Step 8: Test the System

Finally, test the radiator to ensure it's working correctly. Turn on the heating system and check for any leaks or unusual noises. Adjust the TRV to your desired temperature and monitor the radiator's performance.

Common Radiator Installation Mistakes

Unfortunately, many DIY enthusiasts and even some professionals make mistakes during radiator installations. These mistakes can range from improper positioning to incorrect connections. This might lead to reduced heating efficiency and potential damage to the radiator. Some common mistakes include installing the radiator back to front, mounting it vertically when it should be horizontal, or positioning it in a location that obstructs airflow.

Can You Install a Radiator Upside Down or Backwards?

The short answer is no, you should not install a radiator in such a manner. Radiators work most efficiently when installed in a specific orientation as outlined in the manufacturer's instructions. Installing a radiator backwards can disrupt the flow of hot water or steam. And this can lead to uneven heating and potentially causing damage to the unit.

Best Practices for Radiator Installation

To ensure proper radiator installation, follow these tips and tricks:

  1. Read the Instructions: Always start by carefully reading the manufacturer's installation instructions. These guidelines are designed to help you install the radiator correctly and avoid common mistakes.
  2. Positioning Matters: Pay attention to the recommended positioning of the radiator. Typically, radiators are installed horizontally, with the inlet and outlet valves located at the bottom. Avoid obstructing airflow around the radiator, as this can impact heating efficiency.
  3. Check Flow Direction: Before installation, determine which side of the radiator is the flow side. This is where hot water or steam enters the radiator. Connecting the radiator incorrectly can lead to reduced heating performance.
  4. Avoid Obstructions: When choosing a location for your radiator, avoid placing it behind doors or furniture that may obstruct airflow. This ensures that heat can circulate freely throughout the room.

While it may be tempting to take shortcuts during radiator installation, it's important to follow best practices for optimal performance and longevity. Installing a radiator upside down can lead to a host of issues. By following manufacturer instructions, paying attention to positioning and flow direction, you can successfully install a radiator and enjoy efficient heating in your home.


How do I change the position of my radiator? 

Changing the position of your radiator involves a few steps. First, turn off the heating system and allow the radiator to cool completely.

Next, you'll need to drain the radiator and disconnect it from the pipes. Once disconnected, you can remove the mounting brackets and reposition them in the desired location on the wall. Finally, reattach the radiator to the pipes, ensuring all connections are secure. 

Can you mount a radiator vertically? 

Yes, it is possible to mount a radiator vertically. However, it's essential to ensure that the radiator is properly supported and securely fixed to the wall to prevent any accidents or damage. 

What is the best position for a radiator? 

The best position for a radiator depends on various factors, including the layout of the room, the location of windows and doors, and the desired heat distribution. Radiators work best when placed on an exterior wall because it helps heat radiate into the room more efficiently. 

Is it ok to put a radiator behind a door? 

Putting a radiator behind a door is generally not recommended, as it can obstruct airflow and reduce heating efficiency. The door may also block heat from circulating freely around the room, resulting in uneven temperatures. 

Which side of the radiator is the flow? 

The flow side of the radiator is where hot water or steam comes in from the heating system. The flow connection is located at the bottom of the radiator, and the return connection is at the top. Consult the manufacturer's instructions or consult a professional plumber if you're unsure which side is the flow side.