Yes, it is perfectly normal for water to escape when a radiator is bled. You'll likely notice some drips emerging when initially turning the
To first answer your question: No, that is not normal and you have a pretty significant leak somewhere. You're having to replace about a quarter of your coolant every couple of days.
If you let too much water out of a radiator, the overall pressure in your central heating system can drop. This may result in the boiler shutting down or the heating system malfunctioning.
We want to make sure that no water comes out. Occasionally you'll get a bit of water come out as the pressure dissipates from the radiator, but it should stop quickly.
This is an indication that you have debris, a blockage, or most likely, sludge, which has accumulated in the radiator. Hot water is not able to circulate because of the build-up at the bottom of the radiator. The most efficient and safest way to deal with this problem is to seek professional help.
If you don't have any water coming out of a radiator after bleeding, it means you could have something blocking the bleeder valve, the pressure is insufficient in your central heating system, or it could be something different.
It's perfectly normal for some amount of water to come out when you bleed a radiator. If a large volume of water has poured out, it's possible that you opened the valve fully. We recommend not opening it all the way.
Usually, it will take between 20 and 30 seconds to effectively bleed a radiator, but it might take up to a full minute in the case of larger radiators. Get help and advice on bleeding radiators with our expert radiator bleeding guide.
Air pockets, inadequate water pressure and faulty radiator valves or TRVs are the three primary reasons why radiators do not work after bleeding.
The amount of water in a radiator is typically determined by the size of the radiator and the capacity of the heating system. Radiators are often designed to work in conjunction with a specific heating system, so the amount of water they hold will be optimised to work efficiently with that particular system.
Aside from the danger of working with a radiator that has the heating on, it's also an inefficient bleeding process. If the pump is running when you let out air, this will actually cause the system to draw in more air from elsewhere.
In this case, place the blade of your flathead screwdriver in the groove. Then rotate slowly anti-clockwise a quarter until you hear air hissing out. Never fully release a bleed valve. Pressure in the system will force excess water out all over your floors.
If the heating is left on, you not only risk scalding yourself, you might end up with a flood as the water gushes out. It's also not an efficient way to bleed radiators. If the water is pumping when you let out the air, it could be counterproductive and actually cause the system to draw in air instead.
To do this, turn the valve clockwise as far as it will go. Once both valves are closed, the radiator is completely isolated and any repair work can begin.
If the coolant levels are dropping but there is no apparent leak, there may be another problem, such as: a bad head gasket (causing the coolant to flow into the cylinder and evaporate) an invisible leakage point (you may need to use an air pump and pressure to try to make the leak visible)
If no water or air comes out when you bleed the radiator, then the valve could be blocked with paint. Close the inlet and outlet valve at each end of the radiator, then remove the screw from the centre of the bleed valve.
To ensure that the radiator has been balanced, you need to check the temperature. First, using your thermometer, take the temperature at the pipework near the lockshield valve, then take the temperature at the pipework at the other end of the rad near the thermostatic valve.
Bleeding radiators
One of the most common causes of pressure loss is if you've recently bled your radiators. As air is released from your central heating system, it lowers the pressure. So make sure you check the pressure gauge after bleeding a radiator.
After you have finished bleeding all the radiators, make sure you top up the pressure on your boiler.
There are a few possible reasons: Airlock: An airlock is a pocket of bubbles that have become trapped in your radiator. This can prevent hot water from circulating through the radiator, even though the pipes are hot. Blocked radiator valve: The radiator valve controls the flow of hot water.
Don't worry if some black water comes out when bleeding the radiator. It's normal for it to be discoloured, as sediment can settle around the valve.
If your home radiators fail to heat up after bleeding, you should first check for issues with your thermostatic radiator valves, such as a stuck pin on the valve. Alternatively, you can perform a radiator power flush or take steps to ensure your heating system is correctly balanced.
If your home has 2 floors you should begin bleeding the downstairs radiators first. It's also advisable to start with the radiator which is furthest away from the boiler. Once you've bled all the downstairs radiators you move on to the upstairs, again beginning with the radiator which is furthest from the boiler.