Common problems guide

The most common Alpha E-Tec Plus 33 problems

The faults most likely to send a Alpha E-Tec Plus 33 into lockout — with plain-English causes, what to check first, estimated repair costs and whether you need a Gas Safe engineer.

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

The 6 most common faults

01
E10 High DIY-safe

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

What to try first

Locate the external filling loop, which is a flexible braided hose underneath your boiler connected to two valves.Open the valves slowly to allow cold mains water to enter the system until the pressure gauge on the front of the boiler reads between 1.0 and 1.5 bar.Close both valves tightly to prevent over-pressurisation.

Parts
Pressure relief valve, Pressure sensor, Expansion vessel
Full guide for E10
02
10 High DIY-safe

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

What to try first

Locate the external filling loop, usually two silver valves connected by a braided metal hose underneath the boiler.Open the valves slowly to allow water into the system until the pressure gauge on the front of the boiler reads between 1.0 and 1.5 bar.Close both valves firmly and ensure they are fully tightened.

Est. cost
£0-£120
Parts
Filling loop, Pressure relief valve, Pressure gauge
Full guide for 10
03
24 High DIY-safe

Your boiler's control panel has detected that one of its buttons is permanently held down or jammed, preventing the system from operating normally.

What to try first

Switch off the boiler power at the fused spur or mains switch.Carefully inspect the control panel buttons or digital interface for any dirt, debris, or sticky residue that might be holding a button in place.Gently press or wiggle the buttons to see if they can be un-stuck, then power the boiler back on to see if the code clears.

Est. cost
£100-200
Parts
User interface (UI) board, Control panel assembly membrane
Full guide for 24
04
61 High DIY-safe

Your boiler is struggling to push water around your heating system because there is trapped air bubbles inside the pump or a blockage in the pipes.

What to try first

Check your boiler pressure gauge to ensure it is between 1.0 and 1.5 barBleed all radiators in your home starting from the downstairs and moving upstairsTop up the system pressure to 1.5 bar using the filling loop if it dropped after bleeding

Est. cost
£90-180
Parts
Central heating pump, Automatic air vent, System filter
Full guide for 61
05
E01 High Engineer

Your boiler has failed to light because it cannot detect a flame, which means your heating and hot water have stopped working.

Est. cost
£120-250
Parts
Ignition electrode, Gas valve, Condensate trap
Full guide for E01
06
E02 High Engineer

Your boiler has detected that it is getting too hot and has automatically shut itself down to prevent any damage or safety issues.

Est. cost
£120-250
Parts
Pump, Diverter valve, Heat exchanger
Full guide for E02

on the Alpha E-Tec Plus 33

Pressure relief valvePressure sensorExpansion vesselFilling loopPressure gaugeUser interface (UI) 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 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 84-code list for the Alpha E-Tec Plus 33