The Domestic Heating Diagnostic Manual
A comprehensive, full-colour, lay-flat technical guide to understanding, testing and diagnosing domestic heating-control systems.
Knowledge creates confidence.
Understanding creates competence.
Competence creates safer systems.
The book
Made to be used on the job
A physical colour publication for competent professionals, built to be opened on a cylinder, a van floor or next to the boiler.
- 180 × 280 mmPortrait pages, big enough for a full diagram
- Full colourOn every page, so wire colours read as wire colours
- Wire-O bindingLies flat and stays open at your page
- Laminated coverWipe-clean, for a book that gets handled
- Works with the appIts content is in the Heating Decoded app too
Contents
What it covers
Domestic heating electrical controls, how systems operate, and practical diagnostic procedures.
Technical explanations, diagrams, illustrations and practical diagnostic guidance, set out so the method carries over to the next system you meet.
- 01S-Plan
- 02Y-Plan
- 03S-Plan Plus
- 04Safe isolation
- 05GS38
- 06Electrical testing
- 07Continuity and resistance
- 08Wiring centres
- 09Programmers
- 10Thermostats
- 11Motorised valves
- 12Pumps
- 13OpenTherm
- 14Smart controls
- 15Fault-finding sequences
- 16Component identification
- 17Common diagnostic mistakes
Inside the manual
A look at the pages
Electrical testing, from the meter symbols to the control terminals you’ll test between.
Works with the app
The book and the app, side by side
The manual is where you learn a system properly. The Heating Decoded app takes it to site.
The app gives you the manual’s content on your phone, and every system, component and fault links to the matching section, so you can go deeper whenever you need to.
About the diagnostic appWho it's for
Written for competent professionals
Gas and heating engineers
Qualified domestic engineers diagnosing control faults on site.
Electricians
Electricians working on heating controls and wiring centres.
Supervisors and technical managers
People who support engineers and check the work.
Apprentices and trainees
Learners working under appropriate supervision.
Maintenance and housing teams
Maintenance businesses and housing maintenance teams.
Colleges and training centres
Courses, apprenticeships and assessment centres.
Buy the manual
The Domestic Heating Diagnostic Manual
- Printed, full colour
- 180 × 280 mm portrait
- Wire-O lay-flat binding
- Laminated cover
FAQ
Questions people ask
Who is the manual for?
Qualified domestic heating and gas engineers, electricians working on heating controls, supervisors and technical managers, and apprentices and trainees working under appropriate supervision. It isn’t a DIY guide.
Is the manual’s content in the app?
Yes. The Heating Decoded app gives you access to the manual’s content, and links fault information to the matching section, so you can move between the two.
Is there a PDF version?
No. The manual is a printed book, made to be used on the job. Its content is available digitally through the Heating Decoded app.
Can colleges and employers buy in bulk?
Yes. Send us an organisation enquiry with the number of copies you need.
Does it replace manufacturer instructions?
No. It explains how systems work and how to diagnose them. Manufacturer instructions, BS 7671, the Gas Safety (Installation and Use) Regulations and safe working practice always come first.
Heating Decoded is for competent professionals. It doesn't replace manufacturer instructions, BS 7671, the Gas Safety (Installation and Use) Regulations, safe working procedures or your own professional judgement. Isolate and prove dead before you work on any circuit, and follow the instructions for the specific product in front of you.