ACS Gas Pro

ACS Gas Pro — the complete UK gas engineer toolkit. Over 1,250 exam questions across all six core ACS modules — CCN1, CENWAT, CKR1, CPA1, HTR1 and MET1 — plus on-site calculators, a Quick Reference cheat-sheet library, and MyACS, your CP12 / renewal / CPD logbook.

Every question is grouped by sub-topic, with detailed explanations and clause-level references designed to match what you'll see on assessment day.

Whether you're preparing for initial ACS certification, revising before re-assessment, or working on the tools, ACS Gas Pro is built for the job.

CCN1 — CORE GAS SAFETY (743 questions)
The foundation module every gas operative must pass. Topics include:
• Flues & Spillage
• Documentation & Legal Duties
• Unsafe Situations & RIDDOR
• CO Safety
• Ventilation
• Tightness Testing
• Combustion Principles
• Pipework & Fittings
• Gas Rates & Pressures
• Meter Outlet Operating Pressure
• Appliance Safety Devices
• Gas Emergency Actions
• Emergency Isolation Controls
• Meters & Controls
• Purging
• Customer Communication
• Relighting Appliances

APPLIANCE MODULES
• CENWAT (119 questions) — Central Heating Boilers & Hot Water
• CKR1 (93 questions) — Cookers
• CPA1 (88 questions) — Combustion Performance Analysis
• HTR1 (117 questions) — Fires & Wall Heaters
• MET1 (100 questions) — Domestic Meters & Controls

10 ON-SITE CALCULATORS
• Gas Rate (U6 / E6 meter, dial-revolution timing)
• Ventilation Required (room sizing, high/low vents)
• Tightness Test (U6, IGEM/UP/1B)
• Boiler Sizing (heat-loss / DHW demand)
• Calorific Value Lookup (NG / LPG)
• CO/CO₂ Ratio (combustion analyser check)
• Flue Termination Lookup (distances by appliance type)
• Pipe Sizing (copper, steel, length & load)
• Unit Converter (mbar, kW, m³/h, BTU)
• Unsafe Situation Classifier (ID / AR — IGEM/G/11 Edition 2)

QUICK REFERENCE CHEAT SHEETS
Searchable cards covering flue distances, CO/CO₂ limits, standard appliance pressures, ventilation requirements, tightness-test pass/fail criteria, the Unsafe Situations Procedure, pipe-sizing tables and a gas-engineering glossary.

MyACS — YOUR LOGBOOK
• CP12 / Landlord Gas Safety Record log with PDF export
• ACS renewal reminders — never miss a re-assessment date
• CPD log with annual target tracking
• Warning Notices (Immediately Dangerous / At Risk) with PDF export
• Engineer profile (Gas Safe number, business details) auto-filled into every document
• Daily safety refresher card and study streak

KEY FEATURES
• 1,260 questions with full explanations and diagrams
• References to current standards — BS 6891:2015+A1:2019, BS 5440-1:2023, BS 5440-2:2023, BS 6172:2010+A1:2017, BS 669-1:2022, IGEM/G/11 Edition 2 and IGEM/G/13
• Module-specific Mock Tests, 50 questions each
• Flash Cards for quick revision
• Voice-over support (en-GB) for hands-free study on-site
• Progress tracking with visual charts
• PDF export of study reports, CP12 records and Warning Notices
• Works offline once downloaded

WHO IT'S FOR
• Engineers preparing for ACS initial assessment
• Gas operatives revising before re-assessment
• Apprentices working alongside their NVQ
• Trainers reviewing module content
• Working engineers needing on-site calculators and a CP12 logbook

For revision purposes only — always verify against the current ACS scheme rules and manufacturer instructions before any gas work.

Recent changes:
Questions can now be read aloud.

Switch on Voice Over in Settings and each question is read to you as you reach it, along with the answer options. Answer one and you hear whether you were right, what the correct answer was, and the explanation behind it.

Pick the voice and the reading speed in Settings.