Why aren’t your radiators heating up?

If you have a radiator or several radiators that aren’t heating up, there are several possible reasons why this might be happening. Here are some of the most common reasons why radiators fail to heat up:

Air in your heating system

If there is air trapped in your heating system, it can prevent hot water from circulating properly, which can cause your radiators to fail to heat up. One of the most obvious signs that you have air trapped in your heating system is that you have a radiator or radiators that are hot at the bottom but lukewarm or cool at the top. This is because the air is trapped at the top of the radiator, preventing the water from circulating. To fix this problem, you can try bleeding your radiators to release any trapped air.

If you’re constantly having to bleed your radiators, this indicates that the quality of the water in your central heating system may be poor. This is because the water in the system reacts with the metal radiators to form sludge. This can usually be resolved by having Synergy Heat visit to dose your system with anti-corrosion inhibitor to stop this from happening.

Sludge in your heating system

On the other hand, if your radiator or radiators are hot at the top but lukewarm or cool at the bottom, this could be due to a build-up of sludge. This prevents the water from circulating around the bottom of the radiator, causing your radiator to fail to heat up at the bottom. 

If this is the case with a single radiator, then we can flush the radiator to try and remove the blockage. However, if it’s an old radiator, you may prefer to have Synergy Heat replace it with a brand-new radiator.

If lots of your radiators are hot at the top but lukewarm or cool at the bottom, we can power flush your heating system to remove any blockages. Alternatively, if your radiators are old, again, you may prefer to have them replaced with brand new ones.

Faulty radiator valve

If one or both valves on your radiator are faulty or has become stuck, it can prevent hot water from entering the radiator, which can cause it to fail to heat up. In most instances, we’ll be able to replace the valves to get the radiator back up and running. If you have new radiator valves, you may be able to turn the valves a few times to open and close them to dislodge any debris that may be stuck in the valve. This could then allow the water to flow through them again. 

But, if your radiator valves are old, this isn’t recommended, as old valves that haven’t been used for many years have a habit of starting to spontaneously leak after they’ve been turned! If this is the case, the best option is to get in touch with us to arrange an engineer’s visit to diagnose and repair the issue.

Pipework issues

If you live in a larger house with many radiators, or if you have a one pipe central heating system, your radiator or radiators may not be heating up properly because the system is unbalanced. This means that some of your radiators will potentially be receiving too much heat from your boiler, whilst others aren’t receiving enough. To solve this problem, your heating system will need to be balanced. This is a process of adjusting your radiator valves to better allocate the flow of water from your boiler to all your radiators.

It’s also the case that central heating pipework must be correctly sized to ensure that enough water is flowing through the radiators to heat them up. If your flow and return pipework is too narrow, an insufficient amount of hot water will flow through the radiators. This means that they will either take a very long time to get hot, or they will barely heat up at all. To resolve this, a partial or full central heating re-pipe may be required.

Low water pressure

If the water pressure in your heating system is too low, it can prevent hot water from circulating properly, which can cause your radiators to fail to heat up. In this case, you may need to top up the water pressure in your system to get your radiators working properly again. Often, this is a straightforward task that you can carry out yourself, by opening your filling loop to pressurise your heating system to between 1 and 1.5 bar.

If you have an open vented or unpressurised heating system, which is usually filled through a tank in your loft, then the pipework leading to or from your tank could be blocked. If this is the case, then we can unblock or replace the pipework.

Programmer or boiler fault

A common issue when all your radiators aren’t working is that your boiler or central heating programmer has stopped working. With more modern boilers this is usually apparent as they tend to display a fault code which will indicate what the fault may be. If your boiler has broken down or your programmer has broken, then we offer a boiler breakdown response and repair service to get it back up and running as quickly as possible. All you need to do is get in touch with us to arrange a visit.

It could also be the case that your issue relates to an electrical fault, as your boiler requires an electricity supply to operate. In this scenario, an electrician may be required to resolve the electrical issue and restore the electricity supply to your boiler.

Faulty pump

If the pump that circulates hot water around your heating system is faulty or has stopped working, it can prevent hot water from reaching your radiators, which can cause them to fail to heat up. In this case, we can replace the pump to get your heating system working properly again.

Summary

In conclusion, there are several reasons why your radiator or radiators may not be heating up, including air or sludge in the system, a faulty radiator valve, pipework issues, low water pressure, a programmer or boiler fault, or a faulty pump. If you’re unsure about how to fix the problem, it’s best to contact Synergy Heat so that we can arrange for one of our heating engineers to visit you to diagnose the issue and provide you with the appropriate solution.