Common problems guide

The most common Alpha Intec 24GS problems

The faults most likely to send a Alpha Intec 24GS into lockout — with plain-English causes, what to check first, estimated repair costs and whether you need a Gas Safe engineer.

This model is discontinued. Parts can be harder to source and expensive. If repair costs are mounting, a new A-rated boiler may be the smarter choice.
22 documented codes
6 most common
2 DIY-safe checks
4 engineer needed

The 6 most common faults

01
10 High DIY-safe

Your boiler has stopped working because the water pressure inside your heating system has dropped too low.

What to try first

Locate the filling loop, which is a silver braided hose under your boiler connecting two pipes.Open the valves at both ends of the hose to allow water into the system.Watch the pressure gauge on the front of the boiler until the needle reaches the green zone (typically 1.0 to 1.5 bar).Close both valves tightly and remove the filling loop if required by your specific model.

Est. cost
£80-150
Parts
Pressure relief valve, Pressure transducer, Expansion vessel
Full guide for 10
02
24 High DIY-safe

Your boiler's control panel has detected that one of the buttons is physically stuck or jammed, which is preventing the system from operating normally.

What to try first

Switch off the power supply to the boiler at the fused spur or consumer unit.Inspect the control panel buttons to see if any are depressed or visibly stuck.Gently press and release each button several times to see if they spring back into position.Clean around the buttons with a dry, lint-free cloth to remove any sticky residue or trapped dirt.Turn the power back on and see if the error code clears.

Est. cost
£100-£200
Parts
Control panel interface, PCB (Printed Circuit Board)
Full guide for 24
03
01 High Engineer

Your boiler is failing to light the internal flame needed to produce heat or hot water.

Est. cost
£120-250
Parts
Ignition electrode, Gas valve, Ignition lead
Full guide for 01
04
02 High Engineer

Your boiler has detected that it is running too hot and has automatically shut itself down to prevent damage.

Est. cost
£120-250
Parts
Limit thermostat, Pump, Diverter valve
Full guide for 02
05
04 High Engineer

Your boiler has lost the necessary electrical signal to its internal gas supply component, so it has safely shut down to prevent any unsafe operation.

Est. cost
£150-250
Parts
Gas valve wiring harness, Gas valve assembly, PCB (Printed Circuit Board)
Full guide for 04
06
05 High Engineer

Your boiler's temperature-sensing system is detecting an inaccurate reading, which is preventing it from safely heating your home or water.

Est. cost
£150-250
Parts
Flow NTC thermistor, Wiring harness
Full guide for 05
Parts most often replaced

on the Alpha Intec 24GS

Pressure relief valvePressure transducerExpansion vesselControl panel interfacePCB (Printed Circuit Board)Ignition electrode

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 Alpha 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
See the full 22-code list for the Alpha Intec 24GS

Related guides

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