Error P.06

Safety first:

- If you smell gas, stop, ventilate the area, do not operate electrical switches or the boiler, and call the gas emergency number immediately.

- Turn off electrical supply to the boiler only if you are certain and it is safe to do so. Do not remove sealed covers or attempt internal repairs unless you are qualified.

- Only a Gas Safe engineer should work on gas valves, burner, ignition components, PCB or internal wiring.

Initial checks a homeowner can do (no tools or basic tools):

1. Check the boiler display for any additional messages or fault codes and note them. Some faults appear alongside P.06 and give more detail.

2. Read the boiler pressure on the built-in gauge or display. Normal cold-system pressure is typically around 1.0–1.5 bar. If pressure is below ~1.0 bar the system needs topping up.

3. Confirm the external gas supply is on (check other gas appliances or the mains isolation valve at the meter). If gas is off, contact your supplier or restore supply before further checks.

4. Look for visible water leaks under or around the boiler and on radiators. If you find a leak, isolate and call a professional.

5. Check that service/lockshield valves on the boiler flow and return (and any radiator valves) are open.

How to top up boiler pressure (common fix for pressure-related P messages):

1. Locate the filling loop. Combi boilers often have an internal flexible filling loop with a small valve or two isolating taps under the front flap. System boilers may use an external filling loop fitted between the mains cold feed and heating return.

2. Ensure both filling loop valves are closed before you start. Attach the external loop if required and make sure any spring clip is in place if your boiler has one.

3. Open the cold mains isolation valve feeding the loop (if external) and slowly open the filling loop valve(s). Watch the boiler pressure gauge or display closely.

4. Stop when the pressure reaches the recommended value (usually about 1.0–1.5 bar cold). Do not over-pressurise the system. Close the filling loop valve(s) and remove or secure the loop as required by your boiler model.

5. If your boiler needs purging after filling (air in the system), bleed radiators starting from the highest room down to the lowest until water runs without air bubbles, then re-check boiler pressure and top up again if needed.

Reset and test:

1. Use the boiler reset button or follow the reset procedure in your manual (often press and hold reset or use the front control to return to the home screen). Only attempt reset after pressure has been corrected and there are no visible leaks.

2. Observe the boiler for normal ignition and operation. If the P.06 or any fault returns immediately or the boiler fails to fire, proceed to the next section.

Checks to consider before calling a professional:

- If pressure repeatedly drops shortly after topping up, you likely have a leak or automatic air bleed; do not keep topping up—call an engineer.

- If you topped up and the boiler still reports pressure-related faults (sensors or F75/F.75/F.52 style codes referenced in manuals), the pressure sensor (NTC or pressure transducer) may be faulty or stuck and will need diagnostic testing by a technician.

- Check condensate pipe for frost/ice blockages (in cold weather) and ensure tundish and condensate discharge are clear. A blocked condensate can cause lockouts.

When to call a Gas Safe engineer (must call):

- If the boiler still faults after topping up and resetting.

- If there are signs of internal faults mentioned earlier: defective pressure sensor, pump failure, blocked heat exchanger or pipework, ignition failures, mass flow sensor/gas valve issues, PCB errors, or persistent flame/ignition faults.

- If you find a leak you cannot isolate, or the pressure keeps falling.

- For any work involving gas components, burner, ignition, electrical wiring, replacement of sensors, pump, PCB or carrying out a power flush of the system.

Notes and cautions:

- Do not attempt to replace gas valves, ignition components, sensors or open sealed panels; Gas Safe registration is required.

- Avoid repeatedly resetting the boiler as this can mask an underlying fault and may damage components over time.

- Keep records of what you did (pressures, resets, symptoms) to give useful information to the engineer.

If P.06 is a deliberate commissioning/test program that someone activated, exit the programming mode according to the manual; if unsure, have a competent heating engineer confirm that the boiler settings and system filling/purging were completed correctly.