Whether you want to flush clean your central heating system,remove an old radiator or add an inhibitor we have provided some interesting and useful tips to consider when draining and re filling your central heating system.
Below, AEL Heating have outlined the most common way to safely drain the water out of your central heating system and then refill it ready for use.
Draining an Open Vented (Tank Fed) Heating System
Below you will find all the information required to close the feed and expansion tank water inlet valve, drain your radiators and successfully refill the central heating system ready to be brought back into service.
· Turn off your gas or electricity supply to the boiler and make sure the pilot light is no longer on
· Your tank, commonly called the “feed and expansion tank”, will be in the loft. This is commonly filled in the same manner as the cistern in your toilet, using a ball valve – as water rises this lifts the ball which in turn raises the arm and when this reaches a certain level the valve will shut off so no more water can pass into the tank.
· To stop the tank from refilling so you can complete the drain down of the system, place a piece of wood on top of the tank and tie the ball valve in the closed (up) position to keep it closed whilst draining down the heating system and the tank.
· Find a drain valve or a suitable point at the lowest part of your heating system where you can securely attach a hosepipe to ensure water cansafely flow into a bucket or drain.
· Open the drain valve with an adjustable wrench and start to let the water flow out of the heating system. To make this process run a bit quicker open the air bleed valves on all of the radiators in your house starting from the top to the bottom.
· For most households the draining process should take about 20 minutes to completely drain the central heating system.
· When you are satisfied that the central heating system is empty, you can safely flush it through with a cleaner, replace your radiator and then when all the work is completed add the inhibitor via the F & E tank when finally refilling the central heating system with water.
Refilling An Open Vented Heating System
· Once you are sure that the work is completed, the system is flushed though and the system is now empty of water you can then remove the hose pipe and close the drain valve as well as the air bleed valves on all your radiator that you opened at the start.
· To re fill the heating system you must go to the F&E tank in the loft and slowly untie the ball valve, remove the wood and allow the water to fill the tank back up.
· Once the F&E tank is starting to fill, go downstairs and bleed the radiators on the lowest level of the property. Once these have been done, move upstairs and also bleed air out of all these radiators. This will ensure that the whole system is filled with water and air is removed.
· After you have checked that the system is full and water tight, turn the power back on to the boiler.
· It’s not uncommon to hear some knocking sounds in your central heating system as it starts to heat up again, if this is the case then just go to the lowest radiator in the system and start working your way up to the highest radiator to bleed any remaining air that may be trapped.
· Similarly, once the water has been reheated throughout your home, you may need to bleed trapped air out of the radiators again.
· If you find water is coming out of your radiator, chances are you’ll have simply overlooked closing an air bleed valve or not tightened it sufficiently. Give it another turn with an air vent key to shut it off.