Common problems guide

The most common Ravenheat HE120 / HE150 problems

The faults most likely to send a Ravenheat HE120 / HE150 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.
6 documented codes
6 most common
1 DIY-safe checks
5 engineer needed

The 6 most common faults

01
28 High DIY-safe

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

What to try first

Locate the external filling loop, which is usually a small silver braided hose connecting two pipes under the boiler.Open the valves on 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 instructions.

Est. cost
£80-120
Parts
Pressure Relief Valve, Pressure Transducer, Expansion Vessel
Full guide for 28
02
01 High Engineer

Your boiler has attempted to start several times but has failed to light the flame required to produce heat or hot water.

Est. cost
£120-250
Parts
Ignition electrode, Gas valve, Printed circuit board
Full guide for 01
03
12 High Engineer

Your boiler has lost the ability to measure the temperature of the water being used for your heating, so it has shut down to prevent overheating.

Est. cost
£120-200
Parts
NTC heating sensor, Wiring harness
Full guide for 12
04
04 High Engineer

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

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

Your boiler is struggling to detect the temperature of your hot water supply, so it has stopped providing hot water to prevent internal overheating.

Est. cost
£120-200
Parts
DHW NTC Sensor, Wiring harness
Full guide for 06
06
17 High Engineer

Your boiler has stopped working because it cannot properly clear exhaust gases, which is a necessary safety step before it can fire up.

Est. cost
£180-350
Parts
Flue fan, Air pressure switch, Wiring harness
Full guide for 17
Parts most often replaced

on the Ravenheat HE120 / HE150

Pressure Relief ValvePressure TransducerExpansion 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 Ravenheat 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 6-code list for the Ravenheat HE120 / HE150

Related guides

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