How do I repressurise a Glow Worm Compact 24c boiler?
After bleeding a radiator, 2 year old boiler showing zero bar, how do I repressurise?
Replies from 2 tradespeople
Repressurising the Glow Worm compact Boiler is normally via an external filling loop which is attached to the pipework underneath the appliance. It will have a silver hose attached to valves which usually have two black handles. You open one handle fully and open the second handle slowly until you hear the water entering the boiler and watch the pressure gauge until it rises to 1 to 1.2 bar.
To repressurise a Glow-worm Compact 24c combi boiler, follow the simple steps below. This is a common issue after bleeding radiators, as air release causes the pressure to drop.
???? How to Repressurise Your Glow-worm Compact 24c Boiler
???? What You’ll Need:
• Access to the filling loop (usually a silver braided hose beneath the boiler)
• A watchful eye on the pressure gauge (should be visible on the front panel)
? Step-by-Step Instructions:
1. Locate the Filling Loop
• Look under the boiler for a flexible braided hose connecting two copper pipes.
• On either end of this hose, there will be one or two black or grey tap-style valves (or flathead screwdriver-style).
2. Ensure Boiler Is Off and Cooled
• Turn off the heating and allow the system to cool if it’s been running.
• This gives a more accurate pressure reading.
3. Open the Valves Slowly
• Turn both valves (if there are two) slowly to the open position (quarter turn usually).
• You should hear water flowing into the system.
4. Watch the Pressure Gauge
• Keep an eye on the gauge — your target is between 1.0 and 1.5 bar.
• As soon as it reaches the target zone, close both valves immediately.
5. Restart the Boiler
• Turn the boiler back on and reset it if needed.
• Check for normal operation — heating and hot water should now work as expected.
?? Important Notes:
• Never over-pressurise: if you go above 2.5 bar, the pressure relief valve may open.
• If the system keeps losing pressure, it may indicate a leak or failing expansion vessel.
• If you’re unsure whether the filling loop is internal or external, check the manual or send a photo — some models have an integrated filling link.
Let me know if you’d like a diagram or if you’re not seeing the filling loop under your boiler — happy to guide you through with a photo if needed.
