This guide will explain how to bleed a radiator to improve the efficiency of your central heating, and assist in trimming your energy costs.
By bleeding your radiators, you can rid them of any excess air that might be trapped within.
Cold spots on the radiator’s surface can stem from issues with trapped air, reducing their effectiveness and efficiency as a home heating solution.
Radiators operate in cohesion with boilers, so if they aren’t working correctly you can end up paying for your energy despite not actually reaping the benefits it should be providing.
It really is a straightforward task to bleed a radiator – one you can complete by yourself – resulting in cheaper energy bills and a warmer home!
*Please note: If cold spots still remain after your radiators have been bled, you could potentially have a build up of rust or ‘sludge’ in your central heating system. Get in touch with a qualified engineer if this is the case.*
- Radiator Bleed Key
- Towel or cloth to catch drips
Step 1 – Switch on your Home Heating
Initially, switch on your heating so that all radiators in the house come to life. You might find contrasting advice on this step elsewhere, but it is necessary to create a build-up of pressure in your radiators to ensure the air is forced out, so don’t hesitate to do it.
Allow the system a few minutes to heat up before commencing with step two. Please note that cast iron radiators may take a little while longer to heat up.
Step 2 – Which Radiators require bleeding?
When your heating is ready and raring to go, inspect each radiator on an individual basis to see which of them are heating up correctly and which aren’t.
Take care, though! Obviously, radiators can become extremely hot, and the last thing you want is to scald yourself!
Cool spots – particularly those situated close to the radiator’s peak – are a sign that they contain trapped air, and likely require bleeding.
After you’ve identified the cool spots, you can start to bleed the radiator(s).
Step 3 – Bleeding your Radiators
Turn off your central heating and afford the system a little time to cool off, enabling you to handle the radiators without risking injury or completely soaking your floor.
Atop of the radiator you are preparing to bleed, a bleed valve will be positioned at one side.
Place the radiator bleed key in the groove of the bleed valve (alternatively, you might be able to use a screwdriver) and turn it carefully anti-clockwise. A hissing noise should emanate – this is the sound of the air being released.
Keep a tight hold of the bleed key (or screwdriver) until all the trapped air has escaped and water starts to dribble out of the radiator bleed valve.
In the case of more contemporary bleed valves, you might notice the water emerging as more of a ‘jet’ of water as opposed to dribbling out, so you’ll have to be ready and waiting to quickly shut off the valve in this event. Make sure you don’t tighten the radiator bleed valve too securely, to avoid causing potential damage.
Step 4 – Check your Heating System’s pressure gauge
After closing the radiator bleed valve, inspect your boiler’s pressure gauge.
If the pressure level is lower than it should be, you’ll need to adjust the lever on your boiler (AKA the ‘filling loop’) to top up the water levels in your central heating system.
When this has been done, switch your heating back on and perform the same checks as aforementioned. To achieve the desired result, you might need to bleed your radiator(s) and re-pressurize your system two or three times.
*Please note: Be sure to always switch off the power to your boiler when your central heating system is being re-pressurized.*
In order to re-pressurize your home heating, you’ll initially have to identify your central heating filling loop.
This filling loop will be the pipe by which your central heating system and mains water supply are connected.
Although your filling loop isn’t a part of your boiler, it will connect to it, and therefore be positioned nearby.
Should you have an external filling loop, you’ll likely need to turn the taps to let the water enter the system.
Don’t turn any taps apart from those that the filling loop is connected to. The ones you want are usually colored black and could even be etched with the words ‘filling loop’.
Slowly rotate the taps to safely control the water flow into the system, ensuring you don’t exceed the required level – you should be able to hear water travel through the inlet pipe before reaching the central heating system.
Your internal filling loop key could alternatively be attached to a panel at the foot of your boiler, or you may have a pair of filling taps positioned underneath instead.
*Please note: Different installers and manufacturers will suggest contrasting operating pressures for your central heating and boiler. If you aren’t sure what these pressures are, consult a professional for advice.*
As unlikely as it may seem, there are a variety of radiator bleed valves on the market, and it is important to understand which sort your radiators incorporate.
Standard Manual Bleed Valves
Standard bleed valves will be found in plenty of radiators. Failing to incorporate the best elements of design, this type of valve will often allow water to simply leak out when the radiator is being bled.
Chrome Radiator Bleed Valves
This kind of bleed valve typically appears in our designer radiator collection. It boasts impressive aesthetics, but requires caution when being attached. You should also make sure the bleed hole is positioned to face away from the wall.
Lightweight Manual Bleed Valves
Lightweight manual bleed valves are regularly found on the likes of contemporary convector radiators. This type of bleed valve will enable you to adjust the direction of the water spray any way you prefer.
Radiator Bleed Tank
A convenient means for bleeding a radiator, this bleed tank is an ideal option with which to catch water and prevent spills.
Wheel Turn Bleed Valve
Perfect for anyone who’s misplaced a radiator key, simply turn the wheel until your radiator is bled.
Auto Radiator Bleed Valve
The final option is an automatic radiator bleed valve which will only release air when needed by the system. Therefore, there’s no longer a requirement for you to do it yourself, and no need for professional assistance in bleeding your radiator(s).
With regards to energy bills, hot water and heating is sometimes responsible for more than half of our overall outlay. It can prove especially costly for homes with multiple designer radiators and towel warmers etc. (There’s inspiration on some top home heating choices in our Buyer’s Guide to Towel Warmers if you need any).
Considering this, it’s extremely useful to know how to bleed a radiator to cut back on some heating costs where possible. And there are some other tips and tricks you can follow to ensure your central heating system operates with more energy efficiency, in turn also assisting with loosening your budget.
Whilst it might go against your better judgement on the face of it, turning on your home heating during the warmer spring and summer months is well worth doing, just as it would be in winter.
Simply switching on your boiler for between 10 and 15 minutes when the weather is better can help to stop your boiler from breaking down once the weather deteriorates.
You should also regularly inspect your system and be on the lookout for any trouble signals. For example, repeated drops in boiler pressure could suggest a leak in your radiator(s) or pipework, which may mean you require professional assistance.
We’d also recommend having your boiler serviced on an annual basis, which is well worth a typical costing of around $80.
And installing a thermostat onto your boiler, if it doesn’t already have one, offers another money-saving means. This will allow you to pre-set an optimum temperature that your heating won’t exceed, which can prove a cost-effective measure over time.
Insulation is the final point to consider in terms of achieving better yet cheaper heating. Loft insulation and proper draught-proofing surrounding your doors and windows could help you save about $400 per year on your gas central heating costs.
If you need a hand with finding the right spot for your home heating in the first place, consult our guide on where to position your radiator.