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Draining a central heating system

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A central heating system is such an important part of every single home. It provides heating and hot water to the property.

Its essential to have regular maintenance to maintain the performance, and prolong its lifespan. As a result of that it will save you money in the long run.

Don’t know how to drain your heating system? We have created this guide with everything you need to know in steps. Its easy and safe to do yourself, or if you prefer you can get a gas safe engineer out to do the job.

When should my heating system be drained?

A central heating system should be drained if you are installing a new radiator, getting rid of an old one, or putting an inhibitor into the system. An inhibitor is a solution used to prevent rust affecting your cetral heating’s performance. You should always drain it from time to time. This helps to maintain it and reduce the risk for the system having any issues, and save money.

A step-by-step guide to draining your heating system

  • Switch off the system

You should switch the system off completely before you begin for safety reasons. You should also allow the water in the pipes to cool.

  • Turn off water supply to boiler

To do this, turn the stop tap. Its important to make sure the water supply is off and this prevents any water entering the system while you’re draining it.

  • Find the radiator with the drain-off valve

This is usually on the first floor of the property. Once you’ve located it, using a jubilee clip, attach a hose pipe to it (if you have one), and drain the water outside. Alternatively you can use a bucket. If you choose to use a bucket, ect, make sure you close the valve when emptying to prevent any spillages.

  • Bleed the radiators

Open up the valve on all radiators throughout your home. Starting with the ones on the highest floor to make the water drain out faster. Wait 10-15 minutes before opening any further valves downstairs.

To get the water to drain out quicker. Open up the bleed valves on all radiators to let air out the system.

Go back to the radiator you attached the hose or bucket to, and open up the valve. The water will begin to drain out. This could take up to an hour, depending on the system you have.

  • Complete the process

When you are sure all the water is out the system and the process if finished, tighten up the valves on all the radiators, close the valve on the radiator that you started with, and remove the hose/bucket. prepare a container just in case of any extra water coming out.

That’s everything you need to know! Now go and drain your heating system.

What if I don’t have a drain valve?

If you don’t have a drain valve, you should follow steps 1 and 2 and then:

Isolate the radiator from the system

To do this, close the two valves and rotate the regulator in a clockwise direction. You should then remove the plastic cap off the lock-shield and close the valve up tightly using pliers.

Open up the bleed valves

You can the open up the bleed valves to let the air out and speed up the process.

Loosen the nuts and drain

Loosening the coupling nut on the regulator side of the radiator. Place a container under the radiator and rotate the nut counter clockwise until water begins to drain.

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