Error 6 red flashes

Safety precautions:

1. If you smell gas, leave the building immediately and call the emergency gas number or your gas supplier. Do not operate electrical switches or the boiler.

2. Before any checks, switch the boiler off at the control panel and isolate electrical power at the external switch or fuse spur if you need to inspect external pipes or the condensate. Do not remove the boiler casing or attempt internal electrical or gas work.

3. Only carry out the simple external checks listed below. Any work inside the boiler must be done by a Gas Safe registered engineer.

Initial checks a homeowner can do:

1. Note the exact fault display, model and serial number of the boiler and take a photo of the error and the control panel for the engineer.

2. Check for signs of leaks or water around the boiler and pipework.

3. Check the system water pressure on the pressure gauge. Aim for roughly 1.0–1.5 bar when cold. If pressure is well below 1 bar, top up using the filling loop per the boiler manual (open valve(s) until pressure reads 1.0–1.5 bar) and then close the filling loop. If you are unsure where the filling loop is, stop and call an engineer.

4. Check that the gas supply is on: test another gas appliance (hob) if safe to do so, and check any prepayment meter has credit. If there is a gas supply issue, contact your gas supplier.

5. Check the condensate pipe (usually a small plastic pipe to outside) for freezing in cold weather; if frozen, thaw with warm water or a warm cloth—do not use boiling water or direct flame.

6. Inspect the outside flue terminal and air vents to ensure they are not blocked by debris, snow or plants.

7. Check the boiler isolator and any fused spur or RCD has not tripped. Restore power and see if the boiler returns to normal.

Reset and observation:

1. Attempt a single controlled reset: locate the boiler reset button (flame symbol, R or reset button depending on model) and press/hold for 5–10 seconds as per the manual. Do not keep attempting multiple rapid resets; repeated resets can mask or worsen an underlying permanent fault.

2. After reset, allow several minutes for the boiler to run through its normal start sequence. Watch the display and note whether the 6 red flashes return immediately or after a short run.

3. If the fault cleared and the boiler runs normally, monitor pressure and performance for the next 24–48 hours. If the fault reappears, stop and call a professional.

If initial checks do not clear the fault or the fault returns:

1. Do not open the boiler casing or attempt internal repairs. The likely causes at this stage include PCB/control board faults, internal sensor failures, wiring/connectors, fan calibration or other internal parameter errors which require diagnostic tools and safe procedures.

2. Call a Gas Safe registered heating engineer. When you call, provide: boiler model and serial, the exact fault (6 red flashes), what you have already checked (pressure, condensate, reset, gas supply, flue clear), and any other symptoms (no heat, no hot water, noises, leaks, smells).

3. The engineer will run a full diagnostic, check wiring and connectors, read the action log (if available), test sensors, fan, pump and the PCB, and replace or repair faulty components as required. They will also test for safe combustion and flue operation after repair.

Final notes and warnings:

1. A 6 red flash is treated as an unknown/miscellaneous internal fault and usually requires professional diagnosis. Do not attempt internal repair yourself.

2. Do not keep repeatedly resetting the boiler; repeated lockouts indicate a fault that needs investigation.

3. If at any point you detect gas smell or suspect a gas leak, evacuate and call the emergency gas service immediately.

4. Keep records of tests and the engineer report for warranty or future reference.