Sime Brava DGT HE Fault codes & diagnostics

9 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.

Combi Natural Gas 2012-2018 Discontinued
GC Numbers 47-283-3847-283-3947-283-40
Download the Sime Brava DGT HE manual The official installation & service manual (PDF) — the exact document these fault codes were verified against. PDF

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9 High
Versions & GC numbers

Which version do you have?

The GC number on your boiler's data badge identifies the exact appliance and production years, as recorded in the UK Product Characteristics Database.

GC number Appliance (register name) Produced
47-283-40 Brava DGT HE 35 2012–2018
Just want the most common Sime Brava DGT HE faults?
The top 6 problems in plain English — with causes, DIY checks and repair costs.
Fault codes

All 9 documented codes

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AL 02

Your boiler has stopped working because the water pressure is too low and needs to be topped up.

High DIY-safe £0-80

What to check first

  1. Locate the filling loop (usually a silver flexible hose) underneath your boiler.
  2. Slowly open the valve or valves on the filling loop until you hear water flowing.
  3. Watch the pressure gauge on the front of the boiler and close the valves once the needle reaches between 1.0 and 1.2 bar.

Parts commonly replaced

  • Filling loop valves
  • Expansion vessel (if pressure loss recurs)
  • Pressure sensor

Related codes

Full explanation for AL 02
AL 05

Your boiler has detected a problem with the sensor that monitors the temperature of the water being sent to your radiators, which prevents it from heating up correctly.

High Engineer only £90-160

Parts commonly replaced

  • Flow temperature sensor (NTC thermistor)
  • Sensor wiring harness

Related codes

Full explanation for AL 05
AL 06

Your boiler has failed to light the flame or maintain it, causing it to shut down for safety reasons.

High Engineer only £120-250

Parts commonly replaced

  • Ignition electrode
  • Flame rectification probe
  • Gas valve
  • PCB

Related codes

Full explanation for AL 06
AL 07

Your boiler has switched itself off because it has detected that the water inside is getting too hot.

High DIY-safe £90-180

What to check first

  1. Check that all radiator valves are fully open
  2. Bleed all radiators to remove trapped air from the system
  3. Once the boiler has cooled down, try to restart it by pressing the 'R' reset button

Parts commonly replaced

  • Overheat Thermostat
  • Circulation Pump
  • Main Heat Exchanger (Cleaning)

Related codes

Full explanation for AL 07
AL 08

Your boiler is struggling to detect a flame, which means it cannot stay lit to provide heating or hot water.

High DIY-safe £100-280

What to check first

  1. Check that your gas meter is turned on and other gas appliances are working
  2. Press and hold the 'R' Reset button for several seconds to restart the system
  3. Ensure your condensate pipe has not frozen if the weather is extremely cold

Parts commonly replaced

  • Ignition electrode
  • Detection electrode
  • Gas valve
  • Printed Circuit Board (PCB)

Related codes

Full explanation for AL 08
AL 10

Your boiler has detected an issue with an internal sensor or a settings mismatch, which is preventing it from running properly.

High Engineer only £90-180

Parts commonly replaced

  • Auxiliary temperature sensor
  • Wiring harness
  • Main PCB

Related codes

Full explanation for AL 10
AL 13

Your boiler has detected that the exhaust gases are too hot or the sensor monitoring them has failed, causing the system to shut down for safety.

High Engineer only £120-£220

Parts commonly replaced

  • Exhaust sensor (smoke probe)
  • Main PCB

Related codes

Full explanation for AL 13
AL 14

Your boiler has detected an issue with the sensor that monitors exhaust gases, and it has shut down as a safety precaution.

High Engineer only £120-190

Parts commonly replaced

  • Exhaust sensor (smoke probe)
  • Wiring harness

Related codes

Full explanation for AL 14
AL 15

Your boiler has detected a communication problem with the fan, which means it cannot safely clear away exhaust fumes and will not ignite.

High Engineer only £120-350

Parts commonly replaced

  • Fan wiring harness
  • Fan assembly
  • Printed Circuit Board (PCB)

Related codes

Full explanation for AL 15