Updated on 21st November, 2022 by Martin Astley
Central heating is essential in spreading heat around your home to keep you warm in freezing weather. So as a homeowner, it is your responsibility to keep it maintained. One way to do it is to drain your central heating system.
How to Drain Your Central Heating System?
Firstly switch off your heating system and water supply. Wait for a while and let the system get completely cool down. Then locate the radiator with the drain-off valve. After that, open the drain valve and discharge the water. Next, bleed all your radiators to remove the air and refill your central heating system.
What Tools are Required?
- Radiator key
- Jubilee Clip
- Adjustable spanner
What are The Benefits of Draining a Central Heating System?
Draining the central heating system is essential to enjoy heating and hot water throughout the winter. In addition, draining can prevent Limescale, sludge, and water leakage.
Apart from these complications, draining your central heating system is necessary to maintain your central heating system and keep it functioning correctly and efficiently for a more extended period.
Step by Step Guide
In this article, I’ll explain how to drain a central heating system step by step at home without a professional’s assistance. Let’s begin!
Step 1. Switch off your system
Before you drain a central heating system, switch it off completely. And wait for 25-30 mins until the system completely cools down. Likewise, make sure that the radiator is also cooled down. Additionally, if a solid fuel fire powers your boiler, then make sure the fire is out, and your boiler is completely cold.
Step 2. Switch off the water supply
The next step is to turn off the water supply to the boiler. Doing this will prevent the water from entering the boiler or system while you drain it. Most boilers have their stopcock or isolation valve.
If you have a combi-boiler, you will need to close the main shut-off valve, which is usually under the kitchen sink, as hot water is supplied directly to the combi-boiler until there is a pipe with a valve.
Step 3. Locate the radiator with the drain-off valve
After you have switched off the water supply and heating system, it’s time to locate the radiator with the drain-off valve. The radiator can be found on the ground floor or first floor.
Step 4. Open the drain valve and discharge the water
Once you’ve located the drain valve, connect the hosepipe to the drain valve. Use the jubilee clip to safely and securely fasten the hosepipe. As a precaution, place a towel on the floor and cover it. Next, take the hosepipe outside and in the direction of a drain.
Do not simply let the water run into plants or grass because there are frequently numerous chemicals (also known as central heating inhibitors) in this water. Find a major drain instead that can safely be used to drain this water.
Sep 5. Start bleeding your radiators
It’s now time to get to work. First, open the bleed valve to allow the free flow of water through the system. Next, start with the radiators at the top of the building to make the water flow more quickly. Afterward, the radiator bleeder valves downstairs can be opened after waiting for around 10 minutes.
The system can be occasionally air logged, which stops the water from flowing. If this is the case, add around 15 cm of water to the tank and untie the valve. The water will start dripping from the hose in a few seconds. If it doesn’t work, you likely have locked air and should connect the other end of the hose to the cold tap and spray water back into the pipe.
Step 6. Refill your central heating system
You must refill the system when you finish the bleeding and draining process. Start by closing every valve you’ve ever opened and the radiator’s drain cock. Next, connecting the string to the feed tank allows the system to fill with water. Finally, begin bleeding the radiators in the downstairs area once the tank is filled. Repeat the last step with them upstairs, and your system should be loaded.
We advise adding an central heating inhibitor to your system to prevent corrosion and limescale buildup. Turn on the power supply after ensuring all the valves are securely closed. Rebleed the radiators after allowing the system to heat up. Make sure there are no leaks by inspecting all joints and valves.
How to Drain My Central Heating System Without a Draining Valve?
Do you have a central heating system without a draining valve? No need to panic; we got a solution for you also. Follow the steps mentioned below:
- Repeat steps 1 & 2.
- Separate the radiator from the heating system and close its two valves; Regulator and Lockshield.
- To close the regulator, rotate it clockwise.
- To close the lockshield, remove the plastic cap and then tighten it up with the help of a plier.
- Bleed your radiators by opening the bleed valves to let the air out.
- Now locate the coupling nut on the regulator/TRV.
- Put a bucket and some towels under this coupling nut, and then, with the aid of an adjustable spanner, turn the nut counterclockwise until water begins to stream out.
- Keep an eye on this and tighten the coupling nut when the bucket is full. Fill the water up, then carry on. Alternately, connect a hose to the radiator drain using a speed-fit tap.
Are there any risks involved in draining a central heating system?
When you drain your central heating system, always follow step 1: switch off your central heating system and radiator entirely. Because if you don’t do that, it will increase the risk of hot water getting sprayed all over you, which will burn your skin.
How long does it take to drain down a central heating system?
Before you start draining your central heating system, you must switch it off and let it cool down, which will take 25-30 mins. After that, locate the radiator with the draining valve. Bleeding the radiator and refilling the central heating system will take roughly 30 minutes. So the total time required to drain a central heating system is 1 hour.
How often should a central heating system be drained?
Powerflushing your central heating system every 4-5 years is a good practice to keep it running efficiently and effectively. However, if you don’t drain your heating system correctly, water can build up and produce bacteria that cause air density and fungus.
Draining a central system is not a complex job. It can be done by yourself quickly. All you need to do is gather the right tools as we mentioned above plus follow the process, and your central heating system longevity will be enhanced.
Don’t worry if you can’t gather the tools or find it difficult to follow the process, then don’t worry. Instead, call 0345 3192 247, and our team will book your appointment with a certified Gas safe engineer who will visit you and look into your problem. Sometimes the problem may not be entirely related to your central heating system and may be related to your boiler; maybe it is faulty or old. In that case, 24|7 Home will help you get a new boiler quote.
24|7 Home Rescue accepts no liability for any injuries or damages you sustain following the advice on this website. If in doubt, seek professional assistance.