Ideal
The Ideal Logic Combi 24 is a 24 kW natural gas condensing combi boiler, introduced in 2014, offering 89% seasonal efficiency and a 9.9 litres per minute domestic hot water flow rate.
The Ideal Logic Combi 24 is a natural gas condensing combi boiler designed for wall-hung installation in UK domestic properties. Introduced in 2014, this model provides a maximum central heating output of 24.2 kW and a domestic hot water flow rate of 9.9 litres per minute at a 35°C temperature rise. It is manufactured in the United Kingdom and carries a GC number of 47-348-56. This page details technical specifications, installation requirements, and common fault codes for the appliance.
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Full technical specifications extracted from the manufacturer brochure. Empty sections are hidden.
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Use of specific inhibitors (SCALEMASTER GOLD 100, FERNOX, MBI, ADEY MC1 or SENTINEL X100) and scale reducing devices (Fernox Quantomat, Sentinel Combiguard, Calmag CalPhos I) in hard water areas. Artificially softened water NOT permitted.
The Ideal Logic Combi 24 operates as a natural gas condensing combi boiler, providing both central heating and domestic hot water from a single compact unit. Its modulation range extends from 4.8 kW to 24.2 kW for both heating and hot water demands, allowing for efficient operation across varying loads. The appliance achieves a seasonal efficiency of 89% and is classified as a NOx Class 5 boiler. Physical dimensions are 700mm high, 395mm wide, and 278mm deep, with a dry weight of 32.7 kg. The primary heat exchanger is constructed from aluminium, while a plate heat exchanger handles domestic hot water. Installation requires standard 22mm flow/return pipes and a 15mm gas supply, with a 100mm flue outlet. The boiler is OpenTherm compatible and supports various wired and wireless control options, including weather compensation. Safety features include overheat protection, flame failure detection, and frost protection.
Every fault code listed in the manufacturer brochure, with likely causes and engineer actions. Each code has a permalink — paste a URL like https://www.boilertag.com/boilers/ideal/logic-combi-35#fault-f 6 to jump straight to the entry.
| Code | Meaning | Details |
|---|---|---|
| F 6 | Outside Sensor Failure Show causes & actionsUser action Reset the appliance - if the boiler fails to operate then please contact Ideal (if under warranty) or alternatively a Gas Safe Registered Engineer if outside of the warranty period. In IE contact a Registered Gas Installer (RGII). Engineer action Reset the appliance - if the boiler fails to operate then please contact Ideal (if under warranty) or alternatively a Gas Safe Registered Engineer if outside of the warranty period. In IE contact a Registered Gas Installer (RGII). Reset procedure To reset boiler, turn mode knob to reset position and immediately turn knob back to required setting. | Details |
| F 7 | Low Mains Voltage Show causes & actionsUser action Contact a qualified electrician or your electricty provider. Engineer action Contact a qualified electrician or your electricty provider. Reset procedure To reset boiler, turn mode knob to reset position and immediately turn knob back to required setting. | Details |
| F 9 | Unconfigured PCB Show causes & actionsUser action Unconfigured PCB. Please contact Ideal (if under warranty) or alternatively a Gas Safe Registered Engineer if outside of the warranty period. In IE contact a Registered Gas Installer (RGII). Engineer action Unconfigured PCB. Please contact Ideal (if under warranty) or alternatively a Gas Safe Registered Engineer if outside of the warranty period. In IE contact a Registered Gas Installer (RGII). Reset procedure To reset boiler, turn mode knob to reset position and immediately turn knob back to required setting. | Details |
| L 5Lockout | 5 Boiler Resets in 15 minutes Show causes & actionsUser action 1. Turn power off and on at the fused spur. 2. If the boiler fails to operate then please contact Ideal (if under warranty) or alternatively a Gas Safe Registered Engineer if outside of the warranty period. In IE contact a Registered Gas Installer (RGII). Engineer action 1. Turn power off and on at the fused spur. 2. If the boiler fails to operate then please contact Ideal (if under warranty) or alternatively a Gas Safe Registered Engineer if outside of the warranty period. In IE contact a Registered Gas Installer (RGII). Reset procedure To reset boiler, turn mode knob to reset position and immediately turn knob back to required setting. | Details |
| L 6Lockout | False Flame Lockout Show causes & actionsUser action Reset the appliance - if the boiler fails to operate then please contact Ideal (if under warranty) or alternatively a Gas Safe Registered Engineer if outside of the warranty period. In IE contact a Registered Gas Installer (RGII). Engineer action Reset the appliance - if the boiler fails to operate then please contact Ideal (if under warranty) or alternatively a Gas Safe Registered Engineer if outside of the warranty period. In IE contact a Registered Gas Installer (RGII). Reset procedure To reset boiler, turn mode knob to reset position and immediately turn knob back to required setting. | Details |
| C 0 | BCC Activation Fault Show causes & actionsUser action Reset the appliance - if the boiler fails to operate then please contact Ideal (if under warranty) or alternatively a Gas Safe Registered Engineer if outside of the warranty period. In IE contact a Registered Gas Installer (RGII). Engineer action Reset the appliance - if the boiler fails to operate then please contact Ideal (if under warranty) or alternatively a Gas Safe Registered Engineer if outside of the warranty period. In IE contact a Registered Gas Installer (RGII). Reset procedure To reset boiler, turn mode knob to reset position and immediately turn knob back to required setting. | Details |
| C 2 | BCC Fault Show causes & actionsUser action Reset the appliance - if the boiler fails to operate then please contact Ideal (if under warranty) or alternatively a Gas Safe Registered Engineer if outside of the warranty period. In IE contact a Registered Gas Installer (RGII). Engineer action Reset the appliance - if the boiler fails to operate then please contact Ideal (if under warranty) or alternatively a Gas Safe Registered Engineer if outside of the warranty period. In IE contact a Registered Gas Installer (RGII). Reset procedure To reset boiler, turn mode knob to reset position and immediately turn knob back to required setting. | Details |
| F 1 | Low Water Pressure Show causes & actionsUser action Check system pressure is between 1 & 1.5bar on the pressure gauge. If the boiler fails to operate then please contact Ideal (if under warranty) or alternatively a Gas Safe Registered Engineer if outside of the warranty period. In IE contact a Registered Gas Installer (RGII). Engineer action Check system pressure is between 1 & 1.5bar on the pressure gauge. If the boiler fails to operate then please contact Ideal (if under warranty) or alternatively a Gas Safe Registered Engineer if outside of the warranty period. In IE contact a Registered Gas Installer (RGII). Reset procedure To reset boiler, turn mode knob to reset position and immediately turn knob back to required setting. | Details |
| L 1Lockout | Flow Temperature Overheat or No Water Flow Show causes & actionsUser action Check system pressure is between 1 & 1.5bar on the pressure gauge. If the boiler fails to operate then please contact Ideal (if under warranty) or alternatively a Gas Safe Registered Engineer if outside of the warranty period. In IE contact a Registered Gas Installer (RGII). Engineer action Check system pressure is between 1 & 1.5bar on the pressure gauge. If the boiler fails to operate then please contact Ideal (if under warranty) or alternatively a Gas Safe Registered Engineer if outside of the warranty period. In IE contact a Registered Gas Installer (RGII). Reset procedure To reset boiler, turn mode knob to reset position and immediately turn knob back to required setting. | Details |
| F 2 | Flame Loss Show causes & actionsUser action 1. Check other gas appliances in the house are working to confirm a supply is present in the property. 2. If other appliances do not work or there are no other appliances, check the gas supply is on at the meter and/or pre payment meter has credit. If the boiler fails to operate then please contact Ideal (if under warranty) or alternatively a Gas Safe Registered Engineer if outside of the warranty period. In IE contact a Registered Gas Installer (RGII). Engineer action 1. Check other gas appliances in the house are working to confirm a supply is present in the property. 2. If other appliances do not work or there are no other appliances, check the gas supply is on at the meter and/or pre payment meter has credit. If the boiler fails to operate then please contact Ideal (if under warranty) or alternatively a Gas Safe Registered Engineer if outside of the warranty period. In IE contact a Registered Gas Installer (RGII). Reset procedure To reset boiler, turn mode knob to reset position and immediately turn knob back to required setting. | Details |
| L 2Lockout | Flame Loss Show causes & actionsUser action 1. Check other gas appliances in the house are working to confirm a supply is present in the property. 2. If other appliances do not work or there are no other appliances, check the gas supply is on at the meter and/or pre payment meter has credit. If the boiler fails to operate then please contact Ideal (if under warranty) or alternatively a Gas Safe Registered Engineer if outside of the warranty period. In IE contact a Registered Gas Installer (RGII). Engineer action 1. Check other gas appliances in the house are working to confirm a supply is present in the property. 2. If other appliances do not work or there are no other appliances, check the gas supply is on at the meter and/or pre payment meter has credit. If the boiler fails to operate then please contact Ideal (if under warranty) or alternatively a Gas Safe Registered Engineer if outside of the warranty period. In IE contact a Registered Gas Installer (RGII). Reset procedure To reset boiler, turn mode knob to reset position and immediately turn knob back to required setting. | Details |
| F 3 | Fan Fault Show causes & actionsUser action Reset the appliance - if the boiler fails to operate then please contact Ideal (if under warranty) or alternatively a Gas Safe Registered Engineer if outside of the warranty period. In IE contact a Registered Gas Installer (RGII). Engineer action Reset the appliance - if the boiler fails to operate then please contact Ideal (if under warranty) or alternatively a Gas Safe Registered Engineer if outside of the warranty period. In IE contact a Registered Gas Installer (RGII). Reset procedure To reset boiler, turn mode knob to reset position and immediately turn knob back to required setting. | Details |
| F 4 | Flow Thermistor Show causes & actionsUser action Reset the appliance - if the boiler fails to operate then please contact Ideal (if under warranty) or alternatively a Gas Safe Registered Engineer if outside of the warranty period. In IE contact a Registered Gas Installer (RGII). Engineer action Reset the appliance - if the boiler fails to operate then please contact Ideal (if under warranty) or alternatively a Gas Safe Registered Engineer if outside of the warranty period. In IE contact a Registered Gas Installer (RGII). Reset procedure To reset boiler, turn mode knob to reset position and immediately turn knob back to required setting. | Details |
| F 5 | Return Thermistor Show causes & actionsUser action Reset the appliance - if the boiler fails to operate then please contact Ideal (if under warranty) or alternatively a Gas Safe Registered Engineer if outside of the warranty period. In IE contact a Registered Gas Installer (RGII). Engineer action Reset the appliance - if the boiler fails to operate then please contact Ideal (if under warranty) or alternatively a Gas Safe Registered Engineer if outside of the warranty period. In IE contact a Registered Gas Installer (RGII). Reset procedure To reset boiler, turn mode knob to reset position and immediately turn knob back to required setting. | Details |
Patterns that group across the manufacturer's fault-code table. Each entry links to the full code listing further down the page.
User: 1. Turn power off and on at the fused spur. 2. If the boiler fails to operate then please contact Ideal (if under warranty) or alternatively a Gas Safe Registered Engineer if outside of the warranty period. In IE contact a Registered Gas Installer (RGII).
Engineer: 1. Turn power off and on at the fused spur. 2. If the boiler fails to operate then please contact Ideal (if under warranty) or alternatively a Gas Safe Registered Engineer if outside of the warranty period. In IE contact a Registered Gas Installer (RGII).
Triggered by fault code L 5.
User: Reset the appliance - if the boiler fails to operate then please contact Ideal (if under warranty) or alternatively a Gas Safe Registered Engineer if outside of the warranty period. In IE contact a Registered Gas Installer (RGII).
Engineer: Reset the appliance - if the boiler fails to operate then please contact Ideal (if under warranty) or alternatively a Gas Safe Registered Engineer if outside of the warranty period. In IE contact a Registered Gas Installer (RGII).
Triggered by fault code L 6.
User: Check system pressure is between 1 & 1.5bar on the pressure gauge. If the boiler fails to operate then please contact Ideal (if under warranty) or alternatively a Gas Safe Registered Engineer if outside of the warranty period. In IE contact a Registered Gas Installer (RGII).
Engineer: Check system pressure is between 1 & 1.5bar on the pressure gauge. If the boiler fails to operate then please contact Ideal (if under warranty) or alternatively a Gas Safe Registered Engineer if outside of the warranty period. In IE contact a Registered Gas Installer (RGII).
Triggered by fault code L 1.
User: 1. Check other gas appliances in the house are working to confirm a supply is present in the property. 2. If other appliances do not work or there are no other appliances, check the gas supply is on at the meter and/or pre payment meter has credit. If the boiler fails to operate then please contact Ideal (if under warranty) or alternatively a Gas Safe Registered Engineer if outside of the warranty period. In IE contact a Registered Gas Installer (RGII).
Engineer: 1. Check other gas appliances in the house are working to confirm a supply is present in the property. 2. If other appliances do not work or there are no other appliances, check the gas supply is on at the meter and/or pre payment meter has credit. If the boiler fails to operate then please contact Ideal (if under warranty) or alternatively a Gas Safe Registered Engineer if outside of the warranty period. In IE contact a Registered Gas Installer (RGII).
Triggered by fault code L 2.
User: Reset the appliance - if the boiler fails to operate then please contact Ideal (if under warranty) or alternatively a Gas Safe Registered Engineer if outside of the warranty period. In IE contact a Registered Gas Installer (RGII).
Engineer: Reset the appliance - if the boiler fails to operate then please contact Ideal (if under warranty) or alternatively a Gas Safe Registered Engineer if outside of the warranty period. In IE contact a Registered Gas Installer (RGII).
Triggered by fault code F 6.
Diagnostic checklists from engineer-submitted Ideal faults, with step-by-step checks and safety notes.
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Common questions from engineers and homeowners about the Ideal Logic Combi 35.
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Specifications on this page are extracted from the manufacturer brochure. Always cross-check against the latest datasheet before commissioning or quoting. Last updated 28 June 2026.