Ideal Logic Max Combi C24 fault Overheat Lockout 1/4: Customer's got no heating or hot water, boiler's showing 0 bar and…

1. 1. Verify the boiler's electrical isolation.

   Why: Ensuring electrical isolation is paramount for safety before any physical checks or interventions.

   How: Switch off the fused spur to the boiler. Confirm the boiler display is completely blank.

2. 2. Check for the Ideal Logic 2 boiler recall.

   Why: Some Ideal Logic 2 models, including MAX Combi2, have a safety recall due to a fire risk from dry operation. It's critical to ensure the specific boiler isn't affected before proceeding.

   How: Note the boiler's model and part number. Refer to Ideal Heating's official safety notice page or contact Ideal Heating directly to check if the boiler is part of the recall.

3. 3. Re-pressurise the heating system.

   Why: The boiler showing 0 bar pressure is a direct cause of the lockout, as it will not operate below 0.3 bar.

   How: Locate the filling loop, ensure it is correctly connected, and open the valves to allow mains water into the system until the pressure gauge reads between 1 and 1.5 bar. Close both filling loop valves securely.

4. 4. Bleed radiators.

   Why: Air trapped in the system can cause poor circulation and contribute to overheating, even after repressurising.

   How: Starting from the lowest point in the system, use a radiator key to open the bleed valve on each radiator until water flows steadily, then close it. Ensure to re-check boiler pressure afterwards.

5. 5. Reset the boiler.

   Why: After addressing the low pressure and potential air, a reset may clear the overheat lockout fault.

   How: Press and hold the 'Restart' button (often marked with a flame symbol or circular arrow) on the boiler for 3-5 seconds. Only attempt this once.

6. 6. Check the central heating pump operation.

   Why: A seized or faulty pump will prevent water circulation, leading to rapid overheating and lockout.

   How: With the boiler reset and a demand for heating, carefully check if the pump is running (listen for operation, or feel for vibration). If accessible and safe, check for any visible obstructions or signs of seizure. (Requires electrical isolation before any physical intervention).

7. 7. Inspect for system leaks.

   Why: A persistent drop in pressure after repressurising indicates a leak in the system, which needs to be identified and repaired.

   How: Visually inspect all accessible pipework, radiators, and boiler connections for any signs of water leaks. Pay close attention to radiator valves and pump glands.

8. 8. Check the condensate pipe for blockages.

   Why: While less common for an overheat lockout, a blocked condensate can cause other lockouts and should be ruled out, especially in cold weather.

   How: Visually inspect the condensate pipe, particularly external sections, for any signs of freezing or blockage. If safe to do so, gently feel for frozen sections.

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Sources

The AI cross-checked the following manufacturer and trade sources while producing this checklist.

• homeserve.co.uk
• warmzilla.co.uk
• davidosborneheating.com
• freeboilermanuals.com
• bookabuilderuk.com
• idealheating.com
• aanddplumbing.co.uk
• 247homerescue.co.uk
• warmzilla.co.uk
• boilergrants.org.uk
• celsiusplumbers.com