As autumn settles in across London, many households start using their heating more regularly after the warmer months. Before relying on it every day, it is worth carrying out a few simple checks around your radiators and visible plumbing.
A short test can help you spot things such as a radiator that is not warming properly, water around a valve or connection, unusual noises, or changes in how your hot water is behaving. Some checks are straightforward to make yourself, while other problems are better assessed by a professional.
This checklist focuses on radiators, visible pipework, leaks, heating controls and other practical plumbing checks you can make before colder weather arrives. It does not cover boiler servicing or gas-appliance repairs, which require the appropriate specialist expertise.
Three things to check when you first turn the heating on
Before you start relying on the heating regularly, switch it on and give the radiators time to warm up. You are not trying to diagnose the whole system at this stage. The aim is simply to notice anything that does not look, sound or feel normal.
What should a healthy radiator look and feel like?
When the heating is running, a radiator should generally warm up across most of its surface. If one radiator feels noticeably different from the others, or has a persistent cold area, that can be a useful sign that something needs checking.
Cold at the top
A radiator that is warm lower down but remains cold across the top can indicate trapped air. In many cases, bleeding the radiator may help, provided you are comfortable doing so and follow the correct procedure with the heating switched off and the radiator cool.
If the same problem keeps returning, or bleeding does not improve it, further investigation may be needed.
Cold at the bottom
A radiator that is warm at the top but noticeably cold lower down can point to a different issue, such as restricted circulation or a build-up inside the system. Bleeding is unlikely to solve every type of cold spot, so avoid repeatedly doing it if the symptom does not match trapped air.
One radiator stays cold
If a single radiator is not heating properly, first check that its valve or thermostatic radiator valve has not been turned down or left closed.
If the settings appear correct and the radiator still does not warm up, it may need professional attention rather than further trial-and-error adjustments.
Gurgling or unusual noises
Some radiator noises can be caused by air moving through the system. Persistent gurgling, especially when combined with uneven heating, is worth investigating.
The noise itself does not automatically mean there is a serious fault, but it is useful to note when checking the heating after a period of reduced use.
Visible corrosion
Look over the radiator body, valves and nearby connections for obvious rust or deterioration. Surface marks are not always a sign of an active leak, but corrosion accompanied by moisture, staining or dripping water should not be ignored.
Two simple radiator checks worth making
A quick visual and touch-based check can tell you a lot before you start relying on the heating regularly. These two checks are simple enough for most occupants to carry out without taking anything apart.
Look around valves, connections and visible pipework
When you test the heating, take a few minutes to inspect the areas around each radiator as well as any accessible pipework nearby. You are mainly looking for signs that water may be escaping or that a fitting needs attention.
Check around radiator valves and pipe connections for droplets, damp patches or staining. Also look at the floor or wall immediately below the fitting, as a small recurring leak may leave marks even when no water is visible at the time you inspect it. If you notice unexplained dampness or staining without an obvious source, our guide to signs of a hidden water leak explains what else to look for.
Pay attention to any section of exposed pipework that looks wet, damaged or noticeably corroded. A small amount of moisture should not be ignored simply because it is not causing a large leak.
If you are unsure where the water is coming from, avoid dismantling fittings or tightening connections at random. A leak that continues, returns after drying the area, or is difficult to trace may need professional leak and pipe repair.
Check the heating controls and radiator settings
Before assuming a radiator has a fault, check that the heating controls and radiator settings are where you expect them to be.
If a radiator has a thermostatic radiator valve, make sure it has not been left turned down or switched off after the warmer months. A radiator that stays cool may simply be set lower than the others rather than having a plumbing problem.
It is also worth checking that the main heating controls are calling for heat and that the room thermostat is set appropriately for the test.
Finally, make sure furniture, curtains or other large items are not blocking the radiator. Keeping the area around it reasonably clear helps warm air circulate into the room more effectively.
Has your hot water changed as well?
Although hot water is used throughout the year, it is still worth noticing whether anything feels different when the heating starts being used more regularly.
If the water is taking noticeably longer than usual to heat up, is not reaching its normal temperature, or seems inconsistent, make a note of the change rather than trying to diagnose the cause yourself.
A change in hot-water performance can have several possible causes. If the issue appears to need professional attention, Rapid Services can help with relevant hot water and radiator plumbing issues. This section is intended to help you recognise unusual behaviour, not to guide you through boiler or gas-appliance repairs.
Know where DIY checks should stop
“Any work on the gas boiler itself… must be done by a Gas Safe registered engineer.”
Source: Health and Safety Executive (HSE)
Checking whether radiators are warming properly, looking for visible leaks and inspecting accessible water pipework are different from working on a gas appliance. HSE specifically distinguishes this type of water-side or “wet work” from work on the gas boiler itself.
Do not open, service or attempt to repair a gas boiler yourself. If a problem involves the boiler or another gas appliance, the work must be handled by a Gas Safe registered engineer who is qualified for that type of gas work.
This distinction is particularly important when a radiator problem appears to be connected with a wider heating-system issue. Start with the simple checks you can safely make, but know when the problem has moved beyond ordinary radiator or plumbing observations.
What can you check yourself and when should you get help?
There are several simple checks most occupants can make without taking anything apart or attempting a repair.
You can test the heating, compare how the radiators warm up, check valve settings, look for visible moisture and listen for unusual noises. If you are comfortable doing so, bleeding a radiator can also be a reasonable step when the radiator is cold at the top and the heating is switched off and cool.
Professional help is more appropriate when a leak continues or keeps returning, a valve or connection is actively dripping, corrosion is accompanied by moisture, or a radiator still does not heat properly after the basic checks.
It is also sensible to stop if you are unsure what you are looking at or if the problem appears to involve the boiler or another gas appliance. In those situations, the issue should be assessed by the appropriate qualified professional rather than through further trial and error.
Checking heating in a rented property
If you rent your home, it is still worth carrying out the same basic checks when the heating starts being used more regularly. Look for radiators that are not warming properly, visible leaks, unusual noises and any changes in hot-water performance.
If you notice a problem, report it to your landlord or property manager promptly rather than attempting repairs that fall outside normal day-to-day use. In England, landlords are generally responsible for repairs to heating, hot-water systems and associated plumbing installations.
For landlords and property managers, testing the heating before colder weather becomes established can help identify reported issues before tenants depend on the system more heavily.
What to do if you find a problem
If your autumn checks uncover a problem, the next step depends on what you have found.
A simple issue such as a radiator valve being left turned down may be easy to correct. But if a radiator still does not heat properly, a leak keeps returning, a valve or connection is dripping, or visible pipework shows signs of damage, it is better to have the problem assessed rather than keep experimenting with temporary fixes.
If the problem needs professional attention, Rapid Services’ plumbing services cover relevant issues including hot water and radiators, leaks and pipe repairs, and general maintenance and repair where appropriate.
If the problem involves a gas boiler or another gas appliance, use a suitably qualified Gas Safe registered engineer for that work.
A few checks now can make autumn easier
Testing the heating before colder weather settles in gives you a chance to spot small problems before they become more inconvenient.
Check that radiators are warming properly, look for leaks around valves and visible pipework, make sure controls are set as expected, and pay attention to anything unusual with your hot water.
If you find a plumbing issue that needs further attention, dealing with it early can make the transition into colder weather much smoother. And if the problem involves a gas boiler or gas appliance, make sure it is handled by the appropriately qualified professional.