Baxi E118 Fault Code (Baxi and legacy Baxi/Main/Potterton ranges listed on common-code page)

Safety disclaimer

Fault code summary

Manufacturer

Baxi

Fault code

E118

Fault type

Low pressure

Severity

Not specified

Reset

Not specified

Applicable models

Baxi Platinum Compact Combi, Baxi Duo-tec Compact Combi, Baxi Megaflo Compact System, Main Eco Compact Combi & System, Baxi 600 Combi & System, Baxi 800 Combi & System, Baxi Duo-tec Combi, Baxi Assure Combi & System, Baxi Platinum + Combi, Potterton Assure Combi & System, Baxi Platinum + Combi, Baxi Megaflo System, Baxi EcoBlue Combi & System

Quick answer

Water pressure low (below 0.5 bar).

What does this fault code mean?

Water pressure low (below 0.5 bar).

Common causes

• Water pressure below 0.5 bar.

Symptoms

This information was not provided in the verified manufacturer source.

What can the homeowner safely check?

• Read the boiler pressure display/gauge.

Boiler reset information

Reset information was not provided in the verified manufacturer source. Do not repeatedly reset an unresolved fault.

When should I call an engineer?

Contact a suitably qualified heating engineer when the fault persists, the boiler locks out, or the manufacturer instructions do not resolve it. For gas appliance work in the UK, use a Gas Safe registered engineer.

Engineer diagnosis

• Assess system pressure and any continuing water loss.

Applicable boiler models

• Baxi Platinum Compact Combi
• Baxi Duo-tec Compact Combi
• Baxi Megaflo Compact System
• Main Eco Compact Combi & System
• Baxi 600 Combi & System
• Baxi 800 Combi & System
• Baxi Duo-tec Combi
• Baxi Assure Combi & System
• Baxi Platinum + Combi
• Potterton Assure Combi & System
• Baxi Platinum + Combi
• Baxi Megaflo System
• Baxi EcoBlue Combi & System

Related fault codes

• E09 — Baxi and legacy Baxi/Main/Potterton ranges listed on common-code page

  Gas-valve connection fault.

  Read fault code
• E110 — Baxi and legacy Baxi/Main/Potterton ranges listed on common-code page

  Boiler maximum temperature exceeded for gradient, or safety thermostat sensor tripped.

  Read fault code
• E12 — Baxi and legacy Baxi/Main/Potterton ranges listed on common-code page

  Differential water-flow switch fault (still open).

  Read fault code
• E125 — Baxi and legacy Baxi/Main/Potterton ranges listed on common-code page

  Water circulation fault.

  Read fault code
• E128 — Baxi and legacy Baxi/Main/Potterton ranges listed on common-code page

  Safety error for frequent loss of flame.

  Read fault code
• E130 — Baxi and legacy Baxi/Main/Potterton ranges listed on common-code page

  Flue thermostat sensor tripped (lockout).

  Read fault code
• E133 — Baxi and legacy Baxi/Main/Potterton ranges listed on common-code page

  Gas supply fault.

  Read fault code
• E160 — Baxi and legacy Baxi/Main/Potterton ranges listed on common-code page

  Fan fault.

  Read fault code

Manufacturer documentation

E118 | Water pressure LOW (<0.5 bar).

Last verified

2026-09-12

Frequently asked questions