Common problems guide

The most common Ideal LOGIC+ HEAT2 problems

The faults most likely to send a Ideal LOGIC+ HEAT2 into lockout — with plain-English causes, what to check first, estimated repair costs and whether you need a Gas Safe engineer.

10 documented codes
6 most common
2 DIY-safe checks
4 engineer needed

The 6 most common faults

01
4.11 High DIY-safe

Your boiler is not providing central heating even though it may still be providing hot water.

What to try first

Check that your room thermostat or programmer is set higher than the current room temperatureEnsure the heating mode is active on the boiler displayCheck that the radiator valves are open and not turned to zero

Est. cost
£100-250
Parts
External Thermostat, Motorised Diverter Valve Head, Printed Circuit Board (PCB)
Full guide for 4.11
02
4.13 High DIY-safe

Your boiler has lost power or the screen has failed, meaning it will not operate and you cannot see any settings or status messages.

What to try first

Check if other appliances in the house are working to rule out a general power cutCheck your home's main fuse box (consumer unit) to see if a circuit has trippedEnsure the boiler's power switch (usually a fused spur near the unit) is turned on

Est. cost
£100-350
Parts
Display PCB, Main Control PCB, Internal Fuse
Full guide for 4.13
03
Ignition Lockout High Engineer

Your boiler has tried to start five times but cannot get the flame to stay lit, so it has safely shut itself down.

Est. cost
£120-250
Parts
Ignition electrode, Gas valve, Condensate trap
Full guide for Ignition Lockout
04
4.6 High Engineer

Your boiler's fan, which safely pushes exhaust gases out of the flue, has stopped working correctly and is preventing the boiler from firing up.

Est. cost
£250-450
Parts
Fan assembly, Printed Circuit Board (PCB), Wiring harness
Full guide for 4.6
05
4.7 High Engineer

Your boiler detects a flame when it should be off, which is a safety error that prevents the system from starting up.

Est. cost
£180-450
Parts
Gas Valve, Ionisation Lead, Main PCB
Full guide for 4.7
06
4.8 High Engineer

Your boiler has detected an issue with the sensor that monitors the temperature of the water leaving the unit, preventing it from heating your home safely.

Est. cost
£90-160
Parts
Flow thermistor (NTC sensor), Wiring harness / connector, Printed Circuit Board (PCB)
Full guide for 4.8
Parts most often replaced

on the Ideal LOGIC+ HEAT2

External ThermostatMotorised Diverter Valve HeadPrinted Circuit Board (PCB)Display PCBMain Control PCBInternal Fuse

Based on parts cited in our fault code database. Your engineer will confirm what's actually needed after diagnosis.

Call a Gas Safe engineer if…

  • You can smell gas or see signs of a leak
  • The Ideal shows an Emergency or High severity code
  • The boiler keeps locking out after repeated resets
  • You've tried the DIY checks and the fault hasn't cleared
  • There's visible water leaking from the boiler
  • The flame is yellow or orange instead of blue
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See the full 10-code list for the Ideal LOGIC+ HEAT2

Related guides

Boiler losing pressure → No hot water → When to replace → Symptom checker →