SHS Heating Blog

keep updated with our latest news and information

How to re-pressurise boiler

Discover How To Re-Pressurise Boiler

Posted on |

Not Sure Where to Start? Here’s How To Re-pressurise Boiler Easily

Bleeding a radiator helps to release any trapped air inside, which can prevent your heating system from working efficiently. By removing this air, your radiators can heat up properly and warm your home more effectively. This easy-to-follow guide will walk you through how to bleed your radiators safely and also show you how to re-pressurise your boiler if needed. If you’re ever unsure, it’s always best to contact a professional for help.

Discover how to re-pressurise boiler

Keyless Filling Link

  • Check the pressure gauge on your boiler. If the needle is below 1 bar, it’s time to top up the pressure.
  • Gently pull the blue lever down to begin filling the system with water.
  • Keep an eye on the pressure gauge as the water flows in.
  • Once the needle reaches between 1 and 1.5 bar, release the blue lever to stop the filling process.

    •  
    Keyless filling link

    Integral keyed filling link

    Locate the filling key on your boiler, then follow these steps:

  • Insert the filling key firmly into the filling link. Make sure the arrow on the key lines up with the open padlock symbol.
  • Turn the key to the right until it stops. It should now line up with the closed padlock symbol. This connects the two parts of the filling loop.
  • Turn the white knob to the left to let water flow into the system.
  • Keep an eye on the pressure gauge. When the needle rises to between 1 and 1.5 bar, turn the white knob back to the right to stop the water. Don’t overtighten it.
  • Turn the filling key to the left to line it up with the open padlock symbol again, then pull it straight down to remove it. Store the key safely—usually in the bottom panel of your boiler.

    •  
    Integral keyed filling link

    Does your boiler lose pressure every day?

    If your boiler keeps losing pressure and you’re frequently topping it up, that’s a sign something is wrong. This shouldn’t be happening regularly.

    Before looking for visible leaks in your heating system, check the pressure gauge while the heating is on:

  • Does the pressure rise too high before the heating switches off or cools down?
  • Is there a copper pipe outside (called the pressure relief pipe) that’s dripping or spraying hot water?

    • If you notice either of these signs, it’s likely that the expansion vessel inside your boiler needs to be recharged or replaced. This has to be carried out by a Gas Safe registered engineer, this is a very common fault across all boiler brands. During a proper boiler service, the engineer will check and recharge the expansion vessel as part of the routine maintenance.

    So, if you’re experiencing this issue, it could be resolved simply by having your boiler professionally serviced.

    Get your boiler serviced by SHS Heat, Get in touch with our friendly team.

    Scroll to Top