Keston System 2 S30 Fault codes & diagnostics

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

System Natural Gas 2022-present
GC Number 41-930-54
Download the Keston System 2 S30 manual The official installation & service manual (PDF) — the exact document these fault codes were verified against. PDF

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
41-930-54 KESTON SYSTEM2 S30 2022–present
Fault codes

All 1 documented codes

Tap any card for details

L1

Your boiler has failed to fire up multiple times in a short period and has locked itself out for safety.

High DIY-safe £100-£350

What to check first

  1. Switch off the power to the boiler at the main wall switch or fused spur
  2. Wait for 30 seconds
  3. Switch the power back on to see if the boiler resets and fires up

Parts commonly replaced

  • Ignition Electrode
  • Flame Sensing Electrode
  • Gas Valve
  • PCB

Related codes

Full explanation for L1
Status & diagnostic codes

4 operating states & engineer diagnostics

Not faults — these are normal operating states. Tap to expand.

B1 Status Your boiler is experiencing a communication fault between its internal electronic control systems, which is preventing it from operating correctly. C13 Status Your boiler is having trouble venting exhaust gases properly, which has triggered a safety shutdown to prevent any harmful fumes from building up. C33 Status Your boiler has detected an issue with the air supply or exhaust system, meaning it cannot safely remove combustion gases and has shut down to prevent a hazard. C53 Status Your boiler's internal communication system is experiencing a fault, preventing it from operating correctly.
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.