Common problems guide

The most common Vokera Easi Heat Plus 18 problems

The faults most likely to send a Vokera Easi Heat Plus 18 into lockout — with plain-English causes, what to check first, estimated repair costs and whether you need a Gas Safe engineer.

14 documented codes
6 most common
0 DIY-safe checks
6 engineer needed

The 6 most common faults

01
AL10 High Engineer

Your boiler has failed to start because it cannot detect a flame or is flagging a blockage in the drainage system meant to remove water produced during heating.

Est. cost
£120-250
Parts
Condensate trap, Ignition electrode, Gas valve
Full guide for AL10
02
AL20 High Engineer

Your boiler has detected that it is running too hot or that the exhaust system is not venting properly, so it has safely shut itself down to prevent damage.

Est. cost
£120-250
Parts
Limit thermostat, Flue sensor, NTC thermistor
Full guide for AL20
03
AL21 High Engineer

Your boiler has detected a problem with an external add-on, such as a thermostat or clock, which is preventing it from firing up correctly.

Est. cost
£100-250
Parts
External timer, Room thermostat, PCB control board
Full guide for AL21
04
AL26 High Engineer

Your boiler is shutting down because it detects that the water returning from your radiators is far too hot, which suggests an issue with how the heat is circulating through your home.

Est. cost
£150-£300
Parts
Return NTC sensor, Pump, PCB
Full guide for AL26
05
AL28 High Engineer

Your boiler has detected that the water returning to it is hotter than the water leaving it, which suggests a possible issue with the sensors or the pump's performance.

Est. cost
£150-250
Parts
NTC Temperature Sensors, Central Heating Pump, PCB
Full guide for AL28
06
AL34 High Engineer

Your boiler is struggling to detect that the internal fan is spinning correctly, so it has safely shut down to prevent unsafe operation.

Est. cost
£180-300
Parts
Fan assembly, Wiring harness, Printed Circuit Board (PCB)
Full guide for AL34
Parts most often replaced

on the Vokera Easi Heat Plus 18

Condensate trapIgnition electrodeGas valveLimit thermostatFlue sensorNTC thermistor

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 Vokera 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 14-code list for the Vokera Easi Heat Plus 18

Related guides

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