Common problems guide

The most common ECA Proteus Premix 24 HCH problems

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

28 documented codes
6 most common
1 DIY-safe checks
5 engineer needed

The 6 most common faults

01
F37 High DIY-safe

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

What to try first

Locate the filling loop valves beneath your boiler.Open the valves gently to let water in, watching the pressure gauge on the front of the boiler.Stop filling when the needle reaches between 1.0 and 1.5 bar, then firmly close the valves.

Parts
Pressure Relief Valve, Pressure Sensor, Expansion Vessel
Full guide for F37
02
E01 High Engineer

Your boiler has failed to light its burner and safely start up.

Est. cost
£150-350
Parts
Ignition electrode, Gas valve, Printed circuit board
Full guide for E01
03
E03 High Engineer

Your boiler has temporarily shut down because the water inside it has become too hot, triggering a vital safety cutoff to prevent overheating.

Est. cost
£100-250
Parts
High limit thermostat, NTC temperature sensor, Circulating pump
Full guide for E03
04
E05 High Engineer

Your boiler has stopped working because it cannot detect that the internal fan is spinning correctly to clear exhaust gases safely.

Est. cost
£150-300
Parts
Fan Assembly, Printed Circuit Board (PCB)
Full guide for E05
05
E08 High Engineer

Your boiler has detected an issue with the flame during operation and safely shut itself down to prevent any hazards.

Est. cost
£150-300
Parts
Ignition Lead, Electrodes, Gas Valve
Full guide for E08
06
E09 High Engineer

Your boiler is failing to register that the internal gas valve is operating correctly, meaning it will lock out for safety and stop providing heating and hot water.

Est. cost
£150-£300
Parts
Gas Valve, Wiring Harness, Printed Circuit Board (PCB)
Full guide for E09
Parts most often replaced

on the ECA Proteus Premix 24 HCH

Pressure Relief ValvePressure SensorExpansion VesselIgnition electrodeGas valvePrinted circuit board

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 ECA 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
Boiler cover options

Avoid the next call-out bill

Monthly cover means no unexpected bills when your boiler breaks down.

Approved partner
Domestic Appliance Guard
Unlimited call-outs, 24/7 helpline, no price-hike promise
Get a quote →

Affiliate links. We may earn a commission at no extra cost to you.

See the full 28-code list for the ECA Proteus Premix 24 HCH

Related guides

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