How to Drain a Combi Boiler – Step by Step A Guide

How to Drain a Combi Boiler?

Draining a combi boiler may seem like a daunting task, but it is a necessary step to ensure that your heating system is functioning properly. Whether you need to replace radiators or clear blockages from the heating system, draining a combi boiler is a task that can be accomplished with the right tools and know-how. In this guide, London Plumbing Pros will take you through the steps to safely and effectively drain a combi boiler.

How to Drain a Combi Boiler?

When Should You Drain Your Combi Boiler?

There are several occasions when you might want to drain your combi boiler. These include:

  • Replacing radiators or pipes
  • Clearing blockages from the heating system
  • Preventing frozen pipes if you’re going away for a few days during the winter

Before You Begin

Before you start the process of draining your combi boiler, it is important to take some precautions. First, make sure you turn off your combi boiler and disconnect it from the power supply. You’ll also want to wait until the water in the system has cooled down before starting. And, if you are not confident in your ability to complete the task safely, it is best to hire a professional.

Tools You Will Need

To drain a combi boiler, you will need the following tools:

  • Hose
  • Bucket
  • Spanner
  • Radiator valve key

Step-by-Step Guide to Drain a Combi Boiler

Find the Drainage Valve

The drainage valve is usually located in the bottom corner of the lowest radiator in your home. It may also be located outside. If the valve is outside, you won’t have to worry as much about water spillages.

Attach a Hose to the Valve

Attach a hose to the drainage valve and lead it outside. Make sure the other end of the hose is over a drain or somewhere that won’t cause damage.

Open the Valve

Using a spanner, turn the valve to open it. Water will now drain out of the heating system and through the hose pipe. Keep a close eye on the hose pipe as you drain the heating system as it can come off. Also, put a bucket underneath the valve to catch any little dribbles of water.

Open the Bleed Valves on the Upstairs Radiators

After giving the water a few minutes to drain from the heating system, it’s time to turn your attention to the radiators upstairs. Use the radiator valve key to turn the bleed valve on each radiator to open it up. This will allow water to make its way down to the lowest radiator and eventually out through the drainage valve. Drain the other downstairs radiators to get rid of any excess water.

Tighten Up the Valves

Once the water has stopped running out of the hose, your heating system has been drained. Now you can tighten up the drainage valve and all the open bleed valves around your home.

Draining a combi boiler is an important task that should be carried out when necessary to ensure that your heating system is functioning properly. If you’re not confident in your ability to complete the task safely, it is best to hire a professional. At London Plumbing Pros, we have a team of qualified heating engineers who can help you with any plumbing or heating needs. Contact us today to learn more.

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