If your heating system has been underperforming lately or your radiators feel lukewarm, there’s a chance your boiler pressure has dropped. Low boiler pressure is a common issue and can lead to poor heating performance and higher energy bills. The good news? Re-pressurising your boiler is a simple DIY task that many homeowners can manage without calling out a heating engineer. In this guide, we’ll show you how to re-pressurise your boiler safely and effectively.
Step-by-Step Guide: How to Re-Pressurise Your Boiler
Step 1: Check the Pressure Gauge
Open the front panel of your boiler and locate the pressure gauge. This is typically a small dial with ‘bar’ units marked on it. If the needle is below 1.0 bar, it means the pressure is too low and your boiler will need topping up. The ideal range is between 1.0 and 1.5 bar when the system is cold.
Step 2: Locate the Filling Loop
Look underneath the boiler—you should see two silver taps with black knobs and removable end caps. These are part of the filling loop. Unscrew both end caps and set them aside.
Step 3: Connect the Filling Loop
Next, connect the flexible braided filling loop between the two taps. Start by loosely attaching the first wing nut, then fully tighten the second one. Go back and finish tightening the first to ensure a secure fit.
Step 4: Open the Valves
Turn the first tap (usually on the left) to the fully open position. Slowly open the second tap while keeping an eye on the pressure gauge. You’ll hear water begin to flow into the system.
Step 5: Monitor the Pressure
Watch the pressure gauge closely. As soon as it reaches 1.0 to 1.5 bar, close the second tap fully, then close the first. If the pressure continues rising above 2.5 bar, turn off the boiler and contact a professional heating engineer.
Step 6: Finish Up
Once both taps are closed, remove the filling loop and reattach the end caps. Your boiler is now re-pressurised and should begin operating normally again.
Need Boiler Help in Northfield, Ealing, Acton, Hanwell or Pitshanger Lane?
If you’re still unsure about repressurising your boiler or your pressure keeps dropping, Boiler Boys London is here to help. We provide expert heating services and boiler installations across West London. Call us today on 020 8997 0614 or fill out our contact form to book a visit from one of our friendly engineers.
