BoilerFaultCodes F
Boiler has a fault for a specific error. Display will show a number after the “ ” to indicate which error is detected.
Ideal LOGIC SYSTEM Fault codes & diagnostics
21 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
System Gas 2016-present
GC Numbers 41-750-6141-750-6241-750-6341-750-64
Download the Ideal LOGIC SYSTEM manual
PDF
Versions & GC numbers
The fault code is already on your display
Note it down before pressing reset — resetting clears the code immediately. How to read fault codes →
Severity at a glance
Each cell = one fault code. Hover to identify. 21 Unrated
Which version do you have?
The GC number on your boiler's data badge identifies the exact appliance and production years, as recorded in the UK Product Characteristics Database.
| GC number | Appliance (register name) | Produced |
|---|---|---|
| 41-750-61 | LOGIC SYSTEM s15 | 2016–present |
| 41-750-62 | LOGIC SYSTEM s18 | 2016–present |
| 41-750-63 | LOGIC SYSTEM s24 | 2016–present |
| 41-750-64 | LOGIC SYSTEM s30 | 2016–present |
Appliance names and production years are taken from the UK Product Characteristics Database (the SAP/SEDBUK register). Where a GC number is also printed in this model's own manufacturer manual, both sources were checked to agree.
Just want the most common Ideal LOGIC SYSTEM faults?
The top 6 problems in plain English — with causes, DIY checks and repair costs.
Fault codes
All 21 documented codes
Tap any card for details
F1
Low Water Pressure
F2
Flame Loss
F3
Fan Fault
F4
Control / No Flow Thermistor Fault
F5
Return Thermistor Fault
F6
Outside Sensor Fault
F7
LOW MAINS VOLTAGE - CONTACT ELECTRICITY PROVIDER
F8
PCB UNCONFIGURED OR FAULT. SEE SECTION 3.18. IF FAULT PERSISTS REPLACE PCB
F9
PCB UNCONFIGURED OR FAULT. SEE SECTION 3.18. IF FAULT PERSISTS REPLACE PCB
Showing 11–20 of 21
Fn
Flame Loss
FU
DIFF GREATER THAN 50ºC. CHECK ISOLATION VALVES ARE OPEN, CHECK PUMP, CHECK RAD VALVES OPEN, CHECK SYSTEM BLOCKAGES.
L1
Flow Temp Ov’heat Lockout / No Water Flow Lockout
L2
Ignition Lockout
L4
CONTROL/NO FLOW THERMISTOR FAULT
L5
Return Thermistor Fault
L6
False Flame Lockout
L8
PCB UNCONFIGURED OR FAULT. SEE SECTION 3.18. IF FAULT PERSISTS REPLACE PCB
L9
PCB UNCONFIGURED OR FAULT. SEE SECTION 3.18. IF FAULT PERSISTS REPLACE PCB
LC
Restart occurs 5 times within 15 minutes
Showing 21–21 of 21
Ln
Flame Loss
Boiler cover options
Avoid the next call-out bill
Monthly cover means no unexpected bills when your boiler breaks down.
Approved partner
Get a quote →
Domestic Appliance Guard
Unlimited call-outs, 24/7 helpline, no price-hike promise
Affiliate links. We may earn a commission at no extra cost to you.