How do I flush my combi boiler?

Flushing your combi boiler is an important maintenance task that helps to keep the system running efficiently and effectively. Over time, limescale, sludge, and other contaminants can build up inside the boiler, which can cause blockages, reduce efficiency, and even lead to breakdowns. Flushing your combi boiler helps to remove these contaminants and ensure that the system is working at its best.

Here’s how to flush your combi boiler:

Turn off the boiler

The first step is to turn off the power supply to the boiler. This can usually be done by turning off the electrical supply at the wall or isolating the power at the fuse box. You should also turn off the gas supply to the boiler.

Let the boiler cool down

Wait for the boiler to cool down before proceeding with the flushing process. This is important to avoid injury and ensure that the system is safe to work on.

Drain the system

Locate the drain valve on your combi boiler and attach a hose to it. Open the valve and let the water drain out of the system. You may need to use a bucket to catch the water that comes out of the hose. Make sure to dispose of the water safely and responsibly.

Flush the system

Once the system is drained, close the drain valve and fill the system with fresh water. You can do this by turning on the cold water supply to the boiler. Open all the hot water taps in your home to help flush out the system. Keep the taps open until the water runs clear, indicating that the system is free of contaminants.

Add a flushing agent

Once the system has been flushed with fresh water, you can add a flushing agent to help remove any remaining contaminants. Follow the manufacturer’s instructions to add the flushing agent to the system.

Flush the system again

After adding the flushing agent, you should flush the system again with fresh water. This will help to remove the contaminants and the flushing agent from the system. Open all the hot water taps in your home and keep them open until the water runs clear.

Refill the system

Once the system has been flushed and the water runs clear, you can turn off the taps and close the drain valve. Refill the system with fresh water and turn on the power supply to the boiler.

Test the system

Turn on the boiler and check that the heating and hot water are working as they should. Check for any leaks or unusual noises, which could indicate a problem with the system.

In conclusion, flushing your combi boiler is an important maintenance task that helps to keep the system running efficiently and effectively. By following these simple steps, you can remove contaminants from your boiler and ensure that it is working at its best. If you’re unsure about how to flush your combi boiler, or if you notice any issues or leaks during the process, it’s important to seek advice from a professional heating engineer. With the right care and maintenance, your combi boiler can provide reliable and efficient heating and hot water for years to come.