Why Is My Radiator Still Cold After Bleeding?

One of the most frustrating problems when it comes to home heating is not being able to fix a cold radiator.

Just when you thought you’d found the source of the problem, your radiator keeps on bringing you pain. Whilst cold radiators are hardly a new problem, a radiator's inability to heat after bleeding is slightly more unique.

These problems can be from a range of different things but once you’ve diagnosed the problem, it can be easy to get your radiator fixed. You may sometimes need to find a professional to sort out your radiator heating problems.

When Should You Bleed Your Radiator?

There are several signs that you should bleed your radiator. They often begin with the parts of the radiator, or the whole thing not warming up. It may be that your radiator is cold, but most of the time it will be cool or lukewarm, not heating up to its maximum capacity. Another symptom of an un-bled radiator is strange noises coming from it. This could be due to air bubbles being trapped in the pipes of your radiator, meaning that the only way to get them out is to bleed the radiator.

How Do You Bleed A Radiator?

If it turns out that your radiator does need bleeding, there are a few simple steps to take to make sure that you do it properly. Whether it’s a designer radiator or a standard horizontal, the process will always be the same.

To bleed your radiator, simply turn all the radiators on to their maximum temperature. After they have heated up, turn off your radiator system. Starting from the radiator closest to the boiler, turn off your radiator, wait for it to cool, and open the bleeder valve to let all the air escape.

Let whatever water is left inside drip out and then close the valve. Move systematically to the next radiator and do the same. Once you’ve bled all of them, you can check the air pressure in your system through the boiler's green manometer section. For a more detailed guide on how to bleed your radiator, check out our blog.

But what happens when your radiator won’t heat up, even after bleeding your radiator?

Check Your Thermostatic Radiator Valve

The Angled Thermostatic Radiator Valves has a number design to allow you to see your heat settings on your radiator.

One problem may be your thermostatic radiator valve getting stuck. If this is the case, then you may find that your radiator is unable to read when it is supposed to heat up. This is usually due to a stuck pin in the valve.

To check if this is really what the problem is, then remove the cap from your TRV, which is usually the bigger of the two valves. It will also often have numbers around the side. Under this cap, you’ll find the pin which can sometimes get caught in the stuck position. This means that no water is allowed through into the radiator system. Fix this by loosening it with an adjustable spanner, allowing it to fall back into place.

If this doesn't work and you still have issues with your valve we recommend replacing it. We have a range of high-quality thermostatic radiator valves in many styles to match your radiator.

System Balancing

One ailment your radiator may be afflicted with is a case of an unbalanced system. This is when the flow of water around the entire system is uneven, meaning that you need to rebalance your whole system. Before you do, an unbalanced system will usually mean that the last radiator or the one furthest away from the boiler will be the coldest.

If this is the case, you will first have to bleed your radiator before going around to each one and turning the valves off and on. After this, make a note of which ones heat up first and if they are warming up in the order they should be. We have a great step-by-step guide to help you do this effectively.

Flushing Out An Airlock

If there’s an airlock in your radiator, you may want to hire a professional to fix it as it is a complex task. If you’re feeling up to it though, there are some steps you can take.

After shutting the thermostatic radiator valve and lock shield, let the air bleed out using a radiator key. Make sure that you have placed a towel underneath the bleed as it may leak water. After the pressure has lightened, remove the air bleed assembly and add a half-inch male connection which you can connect to a garden hose. After turning the heating system off, connect the hose, the other end leading to a large container. After this, open the thermostatic radiator valve and allow the water to flow out of the radiator through the hosepipe. Any air locked in there should leave the system.

Invest in A Radiator System Inhibitor

Whether it is an electric radiator or a horizontal steam radiator, a system inhibitor will help clear out any clogs inside your radiator. Applying this through the boiler will definitely help to keep your radiator in great shape, leading to a healthy and clog-free system.

Replacing Your Radiator

The Lux Heat Flat Vertical is one of our top sellers. It has a great low price and has a range of size options to fit your room.

We know this isn't what you want to hear but sadly sometimes, even after taking all these steps to try and fix your radiator, it is a losing battle. In the end, radiators do need to be replaced and if your radiator isn't working as it should and you have been recommended by a professional to replace it, or if your radiator is just old and dated then it's time to purchase a new one.

If this is the case you don't have to worry, we have a huge selection of radiators at great prices here at Designer Radiators Direct, from central heating radiators to electric radiators. We understand that in most cases, replacing a radiator is an unplanned expense, so we pride ourselves in being able to offer high-quality luxury radiators at low prices.

Take a look at our Lux Heat Range if you want a stylish radiator with high heat outputs. Lux Heat is our own brand and we have ensured you will receive some of the best prices around, and for added comfort, every Lux Heat Radiator comes with a 10-year guarantee. We even offer a RAL colour matching service on our coloured radiators so you can find a radiator to match your interior perfectly.

Visit our Radiator clearance if you are looking for a budget-friendly radiator. We have a choice of vertical radiators, column radiators and many towel radiators in a range of sizes and colours.