Zero Drop is on the App Store and Google Play

Zero Drop is out on the App Store and Google Play. It is revision for the ACS gas assessments, the theory papers UK gas engineers sit for the certificates of competence that put them on the Gas Safe Register, and sit again every five years to stay on it. It covers core domestic gas safety (CCN1) and boilers and water heaters (CENWAT): 659 questions across 24 topics, from the Gas Safety (Installation and Use) Regulations and tightness testing to ventilation, flues, unsafe situations, condensate, controls and flue gas analysis.

Written from the regulations

The assessments need every answer right, so accuracy comes first. Each question is written from the regulations and standards themselves and names the document and clause it rests on, so you can check it for yourself. Answer one and it shows straight away which option was right, with an explanation and the document and clause to look it up in. On some questions there is a note on why a tempting wrong answer is wrong, or a tip for the job.

Questions on the law are written from official, publicly available government texts: the Gas Safety (Installation and Use) Regulations 1998 and the HSE’s L56 guidance on them, the Gas Safety (Management) Regulations 1996 and RIDDOR 2013. Questions on practice cite the British Standard or IGEM document and clause they rest on. No text from those documents is reproduced.

Practise your way

Pick a module, then a topic and a level, from foundations up to the tricky ones, and 10, 20 or 50 questions at a time, or all of them. Flag any question to come back to. Afterwards, go back over the ones you got wrong or flagged, review a session by all, correct, flagged or incorrect, and see your progress per module, kept from one session to the next.

Try it free

Download it free and try 15 questions from both modules, with every explanation and source in full. One in-app purchase unlocks every question, for good. There is no subscription, no account and no adverts, and it works offline.

It needs iOS 17 or later on iPhone and iPad, or Android 8.0 or later, and it is on both stores in the UK.

Zero Drop is a study aid, not proof of competence. It is independent and unofficial, and not affiliated with, endorsed by or connected to the Gas Safe Register, the Health and Safety Executive, IGEM, BSI or any ACS certification body or assessment centre.

Questions, or something not working? Email support@appyappster.com and you will get an answer from the person who wrote the app. The privacy section for Zero Drop covers both versions.