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Why are my downstairs radiators not working? 

Although lovely blue skies and long days are on the way, we still have some cold nights ahead. So problems with downstairs radiators not working isn’t ideal when you want the living room to be warm and comfortable for the rest of the winter. 

It’s important to ensure that your heating system is working efficiently to minimise costs and if you’ve noticed that your radiators aren’t working downstairs, you need to identify the problem and fix it as soon as possible. 

The good news is, you should be able to fix the downstairs radiators that are not working yourself without expensive plumbing repairs. 

In this blog, we’ll discuss some common reasons why your downstairs radiators are not working correctly, what you can do to fix them and how to prevent it from happening again.

1. Airlocks

One of the most common reasons why radiators may not be working downstairs is airlocks in the heating system. Airlocks occur when air gets trapped in the pipes or radiators, preventing the hot water from flowing properly. 

If the hot water isn’t able to reach the lower section of your heating system, this can result in your radiators working upstairs but not downstairs. This is a common problem if your radiators are fed by droppers from upstairs.

How to fix an airlock

To fix an airlock, you can try bleeding the radiator when the heating is off by using a radiator key to open the valve and let the trapped air escape. Keep bleeding the downstairs radiators until water starts to leak out of the bleed valve.
You can tell if your downstairs radiators need bleeding if they feel hot at the bottom and cold at the top. For more info, head to our how to bleed a radiator guide.
If this doesn’t work, you could try to release the air blockage in the pipes by turning off all the radiators upstairs that are working.
To do this, turn the thermostatic valve down to zero and turn the lockshield valve clockwise all the way with a pair of pliers.
This will isolate the upstairs radiators and could remove the airlock by forcing water to the downstairs radiators that are not working.
bleeding a column radiator

2. Blocked pipes

Another reason why your radiators may not be working downstairs is blocked pipes. Over time, sludge can build up in your heating system caused by a chemical reaction between the water, rust, dirt and the trapped air.

This causes blockages that prevent the hot water from reaching your radiators, preventing them from working properly and efficiently. 

Since sludge is a heavier substance than water, it often sits at the bottom of the radiators and pipework. So you might find that the radiator feels warmer at the top than the bottom. 

This is usually a greater issue on the ground floor of the house which may be the reason why your radiators are getting hot upstairs but not downstairs. 

The sooner you notice this issue, the better! If the heating system is blocked over a long period of time, it can severely damage the boiler and may even lead to potential breakdowns.

How to fix blocked pipes

If you notice that only one or two downstairs radiators are not working, you could try cleaning them out and removing the sludge yourself. 

To do this, you will need to remove the radiator from the wall, empty the water, take it outside and use the hosepipe to flush the dirt out until the water runs clean. Our how to flush a radiator in 10 steps guide has you covered. 

However, if you think that multiple radiators might be filled with sludge, or you don’t feel confident getting the job done yourself, you may need to power flush your system. 

This should be carried out by a heating engineer since it involves using a high-pressure machine and chemicals to remove the blockages and clean your pipes. Our heating system flush guide has all the info you could need on this process.

hose pipe

3. Faulty valves

If your radiators aren’t working downstairs, it’s possible that the valves may be faulty. Valves control the flow of hot water to your radiators, and if they’re not working properly, your radiators may not heat up. 

One common valve problem occurs when the thermostatic radiator valve (TRV) gets stuck in the off position. If your TRV has a numbered dial, you can easily tell if it is trapped if you can’t twist it up to a higher number.

How to fix faulty valves

You can try opening the thermostatic valve back up by removing the valve head (the part with the numbers) and using pliers to turn the metal spindle anticlockwise. But if you find that the valves are damaged, leaking or worn out, you may need to replace them. We have a beautiful collection of radiator valves for you to choose from if you fancy an upgrade. 

close up of a satin radiator valve

4. Unbalanced radiators

When a radiator is unbalanced it means that it can’t heat up as quickly as others because the hot water from the boiler is not being distributed evenly. This can affect the downstairs radiators particularly since hot water rises due to convection. So if your downstairs radiators feel cold compared to the upstairs, they probably need balancing. 

How to balance radiators

What you need to do to balance radiators is turn the heating off, bleed the radiators, turn all the thermostatic and lockshield valves on by twisting them anticlockwise all the way. Then you need to work out which radiators heat up first by turning the heating on and recording how long each radiator takes to get hot. 

After that, turn the heating back off, allow them to cool and turn it back on again. Head to the first radiator that heated up earlier and turn the lockshield valve clockwise all the way. Then make a quarter turn anticlockwise. 

Use a radiator thermometer to record the temperature of the pipework under the lockshield valve, then again under the thermostatic valve. Then, slowly turn the lockshield valve until there is a 12°c difference between that and the original temperature reading.

Finally, repeat the previous step for all the radiators in your home and adjust the lockshield valves until the temperature readings all match. Each lockshield will need to be turned various times because of the distance from the boiler.

For more information, head over to our step by step radiator balancing guide.

5. Boiler pressure issues

If the boiler pressure is too low, it could prevent your downstairs radiators from heating up properly since the water isn’t pressurised enough to send heat from the boiler all the way to the downstairs radiators.

How to fix boiler pressure

Head to the boiler and locate the pressure gauge. You should be able to find it on the front of the boiler under the plastic cover. You will notice the round dial with a red and green zone. If the needle is in the red zone it means that the boiler pressure is too low or too high. The green zone between 1 and 2 bar is what you are aiming for. 

To top up the boiler pressure all you need to do is open the filling loop and keep an eye on the gauge until the dial is in the green zone. Head over to our boiler pressure guide for more information on what the pressure should be when the heating is on and off and how to reduce the pressure.

boiler pressure gauge

Downstairs radiators still not working?

Finally, if none of the above solutions work, it’s possible that there’s a bigger issue with your boiler. A faulty boiler can prevent hot water from circulating properly, which can affect the performance of your radiators. 

If you suspect that your boiler may be the problem, you should call a Gas Safe Registered heating engineer to come and inspect it. Your plumber should also inform you of any serious problems during your annual boiler service.

Ready for new radiators?

We hope this guide has provided a couple of reasons and solutions why your radiators are not working downstairs. By identifying the problem and taking appropriate action, you can ensure that your central heating system is working efficiently and keep your home warm and comfortable throughout the winter months. 

Remember, if you’re not confident in your ability to fix the problem, it’s always best to call a professional for help. And, if you are thinking of updating your heating system, why not take a look at our beautifully designed radiator collection and curate a space you love.

Frequently Asked Questions

Low boiler pressure can stop downstairs radiators from heating up adequately, as the water isn’t pressurised enough to transport heat from the central heating system all the way down to your downstairs home radiators.

To find out more, explore our dedicated blog, Why are my downstairs radiators not working?

You can try bleeding a radiator when the heating is switched off the rectify the issue of airlocks – use a radiator key to open the valve and allow the trapped air to escape. Repeat the process with your downstairs radiators (which airlocks typically affect) until water leaks out from the bleed valve.

Alternatively, you can attempt to alleviate the air blockage in the pipes by switching off all the upstairs radiators that are in working order. You can do so by switching the thermostatic valve to zero and turning the lockshield valve clockwise all the way round using pliers. This will isolate your upstairs home radiators and can potentially tackle the airlock by forcing water to the downstairs radiators that aren’t working properly.

For a more detailed insight, explore our blog, Why are my downstairs radiators not working?

Airlocks within a home heating system are one of the main reasons that can cause downstairs home radiators to not work properly. Airlocks essentially form when air becomes trapped in pipework or radiators to stop hot water from properly flowing.

When hot water can no longer reach the bottom section of a heating system, it can cause your radiators to function correctly upstairs but not downstairs. This issue is more commonplace in cases where radiators are fed by droppers from upstairs.

For further information on airlocks and how to combat them, explore our blog, Why are my downstairs radiators not working?

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