# ACS Gas Pro — ACS Exam Prep - All 6 Modules > UK gas engineer exam preparation with practice questions, calculators, and logbook. (iPhone/iPad app by Eknath Kadam.) - Source: https://appshunter.io/ios/app/acs-gas-pro/id1047795350 (this page in markdown: same URL + `.md`) - Developer: [Eknath Kadam](https://appshunter.io/developer/465355268) - Category: Education, Reference - Price: Free with in-app purchases (on sale, was $9.99) - Age rating: 4+ - Requires: iOS 16.6 · 51 MB - Languages: American English - Released: 2015-10-25 - Data updated: 2026-09-04 - Monetization: free with in-app purchases - User reviews in markdown: https://appshunter.io/ios/app/acs-gas-pro/id1047795350/reviews.md ## What is 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 • iCloud sync across your devices • 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. Privacy Policy: https://www.webrichsoftware.com/privacy.html EULA: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ ## Key features - 1,260+ exam questions with explanations - On-site calculators for gas engineers - Quick reference cheat sheets - CP12 / renewal / CPD logbook - Module-specific mock tests - Voice-over support for hands-free study - Offline functionality ## Pricing and in-app purchases Base price: Free. **Subscriptions** | Subscription | Price | Period | | --- | --- | --- | | Full Question Bank | $19.99 | per 6 months | | Full Question Bank | $9.99 | per month | | Full Question Bank | $14.99 | per 3 months | | Full Question Bank | $29.99 | per year | ## Recent user reviews (8 of 8) All indexed reviews: https://appshunter.io/ios/app/acs-gas-pro/id1047795350/reviews.md ### 5/5 — Great for revising CCN1 safety *2026-05-28* I used this during my CCN1 revision and the explanations made a big difference. The questions are clear and the sub-topic grouping helps me target weak areas, like flues/spillage and emergency actions. Offline mode also comes in handy on site or between calls. ### 5/5 — Flash cards speed up recall for re-sits *2026-05-22* For my re-assessment, I needed faster recall and the flash cards worked well. I’d do a quick round after reading explanations, then focus on the modules that were still uncertain. The app runs smoothly and the charts show progress over time. ### 5/5 — Amazing *2026-05-20* This is great prep tool as well as all calculators and QR screens make it very handy on job ### 1/5 — IET wiring regulations questions *2026-05-19* This app used to be the fully unlocked Electrical IET wiring regulations questions. This new update has completely changed its functionality to the Gas safe regulations. How was this approved?! It’s clearly gaming the App Store because it’s launching a brand new app off the back of the old one because it has high reviews. I’ve never seen an app do this before. I complained to the developer and was given a link to an app similar to the original app but only subscription based. I’d payed for a fully unlocked version originally. The “new” app also has predatory rates. £10 per month or £30 per year. With no option to fully unlock. **Developer response:** Dear user, we have sent you the redemption code to upgrade to latest app which has plenty of new features and latest amendments. Hope this takes care of your concern. ### 1/5 — Questions are all the same *2023-03-25* All the questions are the same never change pointless ### 3/5 — Great app but a couple of flaws *2022-10-23* The app is great and very useful. However I’ve come across a few questions with typos or some even relating to regulations that have been deleted In the latest book. **Developer response:** Thank you for your feedback. We shall fix the mistakes in the data and issue an update within coming 2-3 days. ### 1/5 — Absolute garbage *2022-09-02* Been using this app for couple of weeks, what an absolute piece of crap they put together Don’t waste your money **Developer response:** Hi, we took immense efforts to prepare this new question bank based on the new 2022 amendments, which has many changes and a new chapter introduced. Please let us know what you have found as unacceptable in our app. ### 5/5 — Passed first time with this app *2019-02-16* 5* app Had a lot of questions from this app in the real exam. It even tells you the reference so if you get a question wrong you can look it up. Well done! ## Frequently asked questions about ACS Gas Pro ### What is ACS Gas Pro? ACS Gas Pro is a mobile application designed to help UK gas engineers prepare for their ACS (Accreditation of Certification Scheme) exams. It provides a large question bank, on-site calculators, reference materials, and a logbook for professional development. ### Does ACS Gas Pro have ads? No, ACS Gas Pro is ad-free, allowing for an uninterrupted study experience. This means you can focus on your preparation without any distracting advertisements. ### What modules are covered in ACS Gas Pro? ACS Gas Pro covers all six core ACS modules: CCN1 (Core Gas Safety), CENWAT (Central Heating Boilers & Hot Water), CKR1 (Cookers), CPA1 (Combustion Performance Analysis), HTR1 (Fires & Wall Heaters), and MET1 (Domestic Meters & Controls). ### Can I use ACS Gas Pro offline? Yes, ACS Gas Pro works offline once downloaded. This feature is particularly useful for engineers working on-site where internet connectivity may be limited. ### What are the subscription plans for ACS Gas Pro? ACS Gas Pro offers several subscription plans for the Full Question Bank, including monthly ($9.99), 3-month ($14.99), 6-month ($19.99), and annual ($29.99) options. These plans provide access to all exam preparation materials. ### How does ACS Gas Pro help with renewals and CPD? The app includes a MyACS logbook feature that helps track ACS renewals with reminders and logs Continuing Professional Development (CPD) activities. It also allows for PDF export of CP12 records and warning notices. ### What is the age rating for ACS Gas Pro? ACS Gas Pro has an age rating of 4+. This indicates it is suitable for a wide range of users, though its primary audience is adult gas engineers. ### How often is ACS Gas Pro updated? ACS Gas Pro was last updated on August 10, 2026, with version 15.1. This indicates a commitment to keeping the app current with the latest standards and features. ## Version history (last 5 releases) ### 16 — 2026-08-24 Cloud sync improvements ### 15.1 — 2026-08-10 This release follows a full independent audit of the question bank. NEW QUESTIONS — THE BANK IS NOW 1,260 • Meter outlet operating pressure, from IGEM/G/13: the 18.5–23 mbar acceptance range, the high-operating-load method, the one-minute stabilisation period, the 65 kW / U6 domestic capacity limit, and when a low-pressure supply has to be reported. • More IGEM/G/11 Edition 2 material: the prescribed turn-off order, the At Risk case where turning the appliance off does not remove the risk (and no DANGER DO NOT USE label is attached), RIDDOR 11(1) versus 11(2) duties and their timescales, and what to do as first person at a gas incident. STANDARDS BROUGHT UP TO DATE • References now name the editions in force — BS 6891:2015+A1:2019, BS 6172:2010+A1:2017, BS 669-1:2022, BS 5440-1:2023 and BS 5440-2:2023. • Every reference now points to a clause or section number instead of a page number, so you can find it in whichever copy of the standard you hold. CLEARER, FAIRER QUESTIONS • Reworked the answer options on 132 questions so the wording no longer hints at the right answer. The unsafe-situations questions in particular now test the classification rather than the phrasing. • Removed a duplicated opening line from 620 explanations. • Moved four diagrams that gave their answer away into the explanation, where they belong. • Corrected several source references that pointed at the wrong section. Spotted something that doesn't look right? Get in touch from the Support link on our App Store page — it genuinely helps. ### 15 — 2026-07-07 Bug fixes ### 14 — 2026-06-15 Bug fixes ### 13 — 2026-06-06 Bug fixes ## Apps similar to ACS Gas Pro | App | Rating | Price | Category | | --- | --- | --- | --- | | [CiNii Research, KAKEN, IRDB](https://appshunter.io/ios/app/cinii-research-kaken-irdb/id1618150440) | — | Free | Education | | [Smart Belarusian Dictionary](https://appshunter.io/ios/app/smart-belarusian-dictionary/id1606872160) | 3.0 (1) | Free | Education | | [Zuokabi: Learn Spanish](https://appshunter.io/ios/app/zuokabi-learn-spanish/id1615570420) | 5.0 (22) | Free | Education | | [NSE Panthers](https://appshunter.io/ios/app/nse-panthers/id1611182360) | 4.7 (3) | Free | Education | | [Wanna help word memorization](https://appshunter.io/ios/app/wanna-help-word-memorization/id1608671720) | — | Free | Education | | [A-Level Biology App](https://appshunter.io/ios/app/a-level-biology-app/id1613078220) | 1.0 (1) | Free | Education | ## More apps by Eknath Kadam - [Fire Regs Pro](https://appshunter.io/ios/app/fire-regs-pro/id298805078) - [RetrofitReady : Installer Exam](https://appshunter.io/ios/app/retrofitready-installer-exam/id304488056) - [EV Charging Exam](https://appshunter.io/ios/app/ev-charging-exam/id307591553) - [2391 Inspection & Testing Pro](https://appshunter.io/ios/app/2391-inspection-and-testing-pro/id307859563) - [RetrofitReady : DEA Exam](https://appshunter.io/ios/app/retrofitready-dea-exam/id324520045) - [Solar PV & Battery Storage Pro](https://appshunter.io/ios/app/solar-pv-and-battery-storage-pro/id351685979) All apps by Eknath Kadam: https://appshunter.io/developer/465355268 --- *Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-09-04.*