Glow-worm ULTIMATE 2 35c Fault codes & diagnostics

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

Combi Gas 2015-present
GC Number 47-019-36
No manual available yet We don't hold the official service manual for this model yet. We're sourcing it.

The fault code is already on your display

Note it down before pressing reset — resetting clears the code immediately. How to read fault codes →

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
47-019-36 ULTIMATE 2 35c 2015–present

Appliance names and production years are taken from the UK Product Characteristics Database (the SAP/SEDBUK register). Where a GC number is also printed in this model's own manufacturer manual, both sources were checked to agree.

Fault codes

All 2 documented codes

Tap any card for details

F.22

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

High DIY-safe

What to check first

  1. Locate the filling loop valves underneath your boiler.
  2. Open both valves gently to let water into the system until the pressure gauge on the front reaches between 1.0 and 1.5 bar.
  3. Close both valves tightly and reset the boiler if it does not restart automatically.

Parts commonly replaced

  • Filling loop
  • Pressure sensor
  • Expansion vessel

Related codes

Full explanation for F.22
F.28

Your boiler has tried to start up three times but failed to ignite, so it has locked itself out for safety.

High Engineer only £150-350

Parts commonly replaced

  • Ignition lead
  • Electrodes
  • Gas valve
  • PCB

Related codes

Full explanation for F.28
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