How to Fix a Baxi Boiler 110 Error Code

Overview

The Baxi 110 error code indicates low water pressure in your heating system. This is one of the few boiler errors you can safely fix yourself. This guide covers repressurising a Baxi boiler.

Step-by-Step Fix

1. First check the pressure gauge on the front of your Baxi boiler. The gauge is usually a dial or digital display and shows the current system pressure. When the heating is cold the pressure should read between one and one point five bar. If the pressure is below one bar and the boiler is showing the 110 code the system needs repressurising.
2. Locate the filling loop. On most Baxi boilers the filling loop is a flexible silver hose underneath the boiler with a valve at each end. Some Baxi models have a built in filling loop with a single valve or a key mechanism. Consult your boiler manual if you are unsure where the filling loop is.
3. Open the filling loop valves slowly. Turn one valve fully open then gradually open the second valve while watching the pressure gauge. You will hear water flowing into the system. Allow the pressure to rise to one point five bar. Do not overfill the system. If the pressure rises above two bar the pressure relief valve may activate and release water.
4. Close both filling loop valves firmly once the pressure reaches one point five bar. Ensure they are fully closed to prevent over pressurisation. If the filling loop is detachable remove the hose and store it safely. Check that no water is dripping from the filling loop connections.
5. Reset the boiler by pressing the reset button on the front panel. The reset button is usually marked with a circular arrow symbol. Hold it for a few seconds until the boiler attempts to restart. The 110 error should clear and the boiler should fire up.
6. Check the pressure gauge again after the boiler has been running for ten to fifteen minutes. The pressure may rise slightly as the water heats and expands which is normal. If the pressure rises above two point five bar when hot there may be an issue with the expansion vessel.
7. Monitor the boiler over the next few days. If the pressure drops again and the 110 code returns within twenty four hours there is likely a leak in the system or a faulty pressure sensor. Check all visible pipework and radiators for leaks including under sinks around the boiler and at radiator valves.
8. If you cannot find any visible leaks and the pressure keeps dropping call a Gas Safe registered engineer. There may be a hidden leak under the floor or the pressure sensor may be faulty. Do not continue to repressurise the system repeatedly without investigating the cause.
9. To prevent future low pressure issues check the system pressure monthly and address any drops promptly. If you have recently bled radiators the pressure will have dropped and will need topping up. Regular maintenance including an annual boiler service helps keep the system running efficiently.

Common Symptoms & Diagnostic Resolutions

Review the common error codes and operating symptoms below to quickly identify the root cause of the fault before ordering replacement parts.

Frequently Asked Questions