Free Advice
We aim to provide advice that could help with common issues, such as filling your boiler or bleeding your radiators. Low pressure is a very common fault, and following these steps could help tide you over until we can diagnose any underlying issues.
How to Fill Your Boiler:
The filling loop is a flexible pipe that connects the boiler to the water supply. You’ll usually find it under the boiler, but it may also be located nearby.
Some boilers have a built-in filling loop; others may have a separate external one.
Step 1: Open the Filling Loop Valve
To begin topping up, you’ll need to open the valve on the filling loop:
Turn the valve slowly in the direction that opens it. You’ll hear the water flowing in.
Step 2: Monitor the Pressure Gauge
While you’re opening the valve, keep an eye on the pressure gauge. When the needle reaches 1-1.5 bar, stop opening the valve.
Tip: Don’t let the pressure go above 2 bar.
Step 3: Close the Valve
Once the correct pressure is reached, close the valve tightly to stop the water flow. Make sure there are no leaks.
How to Bleed Air Out of Your Radiators:
Bleeding radiators is an essential task in maintaining a heating system. Over time, air can get trapped in the radiator, causing it to heat unevenly or not warm up at all. Bleeding removes the trapped air, allowing hot water to circulate freely, ensuring your radiator heats up properly.
Step 1: Turn Off the Heating and Allow the System to Cool
Before starting, turn off the heating system and allow the radiator to cool completely. This is crucial for your safety and to avoid any burns.
Wait for about 30 minutes after turning off the heating.
Step 2: Gather the Tools You’ll Need
- Radiator key (a small tool that fits into the bleed valve)
- A cloth or small container to catch any water that may spill out
- A flathead screwdriver (if needed for some models)
- A pair of gloves (optional for extra protection)
Step 3: Locate the Bleed Valve
The bleed valve is usually located at the top of the radiator, often on one end. It’s a small valve that looks like a round or square nut.
Tip: If you’re unsure where it is, check near the pipe that connects the radiator to the heating system.
Step 4: Open the Bleed Valve
Place your cloth or container directly under the bleed valve to catch any drips. Insert the radiator key (or flathead screwdriver, if applicable) into the valve and slowly turn it counterclockwise—usually about a quarter to half turn is enough.
You should hear a hissing sound as the trapped air begins to escape. Be cautious and open the valve slowly to control the release.
Step 5: Wait for Water to Start Dripping
Once water starts to come out steadily instead of air, this means all the trapped air has been released. At this point, tighten the valve by turning it clockwise until it’s snug—but avoid overtightening, which could damage the valve.
Step 6: Check the Boiler Pressure
After bleeding the radiators, it's a good idea to check the pressure on your boiler. Releasing air can sometimes cause a slight drop in system pressure. If the pressure is too low (usually below 1 bar), you may need to top it up using the filling loop on your boiler.
Step 7: Turn the Heating Back On
Switch the heating back on and allow the system to warm up. Check the radiator you bled to ensure it's heating evenly. If it still feels cold at the top, you may need to repeat the process.
Regular Maintenance Tip:
It’s good practice to bleed your radiators once or twice a year—especially at the start of the colder months—to keep your heating system running efficiently.