How to Top Up Boiler Pressure: A Simple Guide
Introduction
If your central heating isn’t working properly, or your boiler keeps cutting out, the pressure may be too low. This is a common issue for homeowners in Glasgow, especially during winter when your system works hardest.
In this guide, Gaswegian — Heating the Region explains what boiler pressure is, why it matters, and how to safely top it up yourself.
1. What Is Boiler Pressure?
Boiler pressure is the level of water pressure inside your heating system. Most modern boilers work best between 1 and 1.5 bar. If the pressure drops too low, your boiler may stop working — leaving you without heating or hot water.
2. How Do I Know If My Boiler Pressure Is Low?
Check the pressure gauge on the front of your boiler.
- If the needle is below 1 bar, your pressure is too low.
- If it’s above 2.5 bar, your pressure may be too high.
Low pressure usually happens after bleeding radiators, small leaks, or over time as water escapes from the system.
3. How to Top Up Your Boiler Pressure (Step by Step)
⚠️ Always make sure you follow your boiler manufacturer’s instructions. If you’re unsure, call a Gas Safe engineer.
- Switch off your boiler and let it cool down.
- Find the filling loop — usually a silver, flexible hose with two small taps/valves at either end.
- Open the valves slowly until you hear water entering the system.
- Watch the pressure gauge rise to around 1.2–1.5 bar.
- Close both valves securely.
- Turn your boiler back on and check it’s working properly.
4. What If the Pressure Keeps Dropping?
If your boiler pressure keeps falling, it could mean there’s a leak in the system or a faulty part. Topping up repeatedly is not a long-term fix — you’ll need a Gas Safe engineer to find and repair the problem safely.
Conclusion
Topping up your boiler pressure is quick and easy, but if you’re unsure or the problem keeps coming back, it’s time to call the experts.
At Gaswegian, we’re Gas Safe registered and experienced in dealing with all types of boilers. From simple pressure problems to emergency breakdowns, we’ll get your system running safely and efficiently.
👉 Need help with your boiler in Glasgow? Contact Gaswegian today and book a visit.
