How to vent a radiator

Do some of your radiators feel cold at the top and warm at the bottom? If so, this is being most probably caused by air that has been trapped in your radiator. You should be able to fix this  yourself by venting your radiators.

Venting a radiator is a simple, safe and process. Basically it just means opening a small valve on your radiator to allow any trapped air to escape.

Before you vent the radiators, please turn off your central heating system. This will prevent more air from entering the system and damage to the system.

Find the bleed valve this usually has a small grub screw and is located on one side at the top of the radiator.

Place a cup or old rag underneath the bleed valve to catch any excess water. Also be careful as the water that escapes from the radiator may be very hot.

Your radiators should have come with a small radiator key. If you can’t find the radiator key you should be able to buy one any DIY store.

The air vent should be  at the top of one side of your radiator. To vent your radiator, insert the radiator key into this valve or flat screwdriver with some air vents and carefully turn it anticlockwise. The air trapped in your radiator will start escaping with a hissing sound. When water begins to dribble out out the valve you will know that all the air has been removed from the radiator, the proceed to close clockwise not to tight. Your system should have a chemical inhibitor added to your system every 2 -3 years as this helps keep your boiler and central heating system in optimum condition and prevents boiler problems and system failures.

Still need help?

If the problem isn’t resolved by the advice above, or you’d rather not tackle it yourself, just give us a call on 07855 382 189.

How to defrost a frozen condensate pipe

Even the best-tended boiler will struggle to function if its condensate pipe freezes. Luckily, it’s not a difficult job to put things right if it does happen. This handy guide will help you get your boiler up and running quickly and easily.

 What is a condensate pipe?

A condensate pipe carries condensation from your boiler to your outside drain. It’s usually a white or grey plastic pipe that travels from your boiler through the external wall directly outside where your boiler is located.

During cold weather the condensation in this pipe may freeze and cause a blockage causing the condensate to back up into the boiler and cause a shutdown.

condensate-pipe-diagram
Condensate pipe emerging from the external wall.

 How to defrost the pipe

If you suspect that your boiler condensate pipe has frozen, following steps should help you get things back to normal quickly. Remember, if you don’t feel competent to follow this guidance then you should contact a expert boiler engineer for help.

  1. Confirm the condensate pipe is frozen
    Depending on the make of your boiler, a frozen condensate pipe may be indicated by a ‘fault code’ or warning light on the boiler’s display. Gurgling or bubbling sounds coming from the boiler or the condensate pipe are another sign that the condensate pipe has frozen.
  2. Locate the blockage
    The pipe is probably frozen at its most exposed point. This may be the open end of the pipe, or at a bend or elbow. Running your hands over the pipe until you find a section that feels colder than the rest should help you identify the blockage quickly.
  3. Thaw the pipe
    Using a jug or watering can, pour warm water along the length of the pipe, repeating the process until the pipe has thawed (don’t use boiling water as this can crack or damage the pipe). Alternatively, you can use a hot water bottle or a heat pack to slowly defrost the pipe.
  4. Restart your boiler
    Once the frozen section has been melted and cleared, check your boiler manual for instructions on how to reset the boiler correctly. Your boiler should now restart correctly. If you boiler doesn’t restart you will need to call out a qualified boiler engineer.

condensate-pipe-defrost
Pouring warm water along the length of the pipe.

 How to prevent the pipe from freezing again

You can avoid future stress by taking some steps to help prevent the condensate pipe from freezing again.

If your condensate pipe isn’t already insulated, wrap it in some old towels immediately to prevent it freezing again. As soon as you can, get down to your local DIY store and buy some foam pipe insulation to wrap the condensate pipe in. This insulation comes in a variety of sizes, so measure the pipe’s diameter before you buy.

condensate-pipe-insulate
Condensate pipe wrapped in foam insulation.

During extreme weather conditions, even proper insulation may not be enough to prevent the condensate pipe from freezing. It may help to temporarily run your boiler with the boiler thermostat set as high as possible for as long as the cold spell lasts. But if you continue to experience problems, just give us a call.