ST0303 Plumbing and Domestic Heating Technician: practice questions and mock tests
A route-based assessment built around a shared 60-question core paper, followed by integrated gas theory, two environmental papers or one non-domestic paper.
Apprentices registered to ST0303 version 1.2 on the gas, environmental technologies or non-domestic plumbing option.
Standard
ST0303
Version
v1.2
Level
3
Exam at a glance
ST0303 · version 1.2
- Questions / papers
- 60 core + 1 route paper
- Time allowed
- 120 min + route paper
- Pass requirement
- 36/60 core + route paper
- Reference policy
- Closed book (gas varies)
What is the ST0303 Plumbing and Domestic Heating Technician test?
The ST0303 knowledge assessment checks the shared plumbing and heating knowledge required by every apprentice and the specialist theory for the occupational option recorded on their programme.
This page focuses on the knowledge-test method. The full end-point assessment may also include practical, observation or professional-discussion methods. Use the official assessment-plan links below to check the complete EPA.
When you take it
It is normally taken during end-point assessment, after the apprentice has completed training and passed through gateway. The employer, training provider and end-point assessment organisation agree the booking and sequence.
All apprentices take core Paper 1: 60 four-choice questions in 120 minutes, with 36/60 required to pass. Gas-route apprentices also take integrated Paper 2 comprising the CCN1 or equivalent theory tests and the CENWAT or equivalent theory test; its conditions and marking are controlled by the accountable Awarding Body, and both papers must be passed. Environmental-route apprentices take both Paper 2a, Air Source Heat Pumps, and Paper 2b, Solar Thermal: 30 questions and 60 minutes each, with 18/30 required in each. Non-domestic apprentices take Paper 2, 9289-303: 30 questions in 60 minutes, with 18/30 required.
- 01
Training
Build the occupational knowledge, practical competence and workplace evidence.
- 02
Gateway
The employer confirms the apprentice is ready to enter end-point assessment.
- 03
Knowledge test
Sit the ST0303 core and route knowledge assessment.
- 04
Other EPA methods
Complete the practical, observation or discussion methods specified by the assessment plan.
Try a practice question
ST0303 · Original practice material
A technician is reviewing health and safety law, duties, guidance and enforcement.
Which statement about shared responsibilities is correct?
Choose one answer, then check it.
ST0303 exam format and scoring
These are the recorded rules for this standard version. Always compare them with the final joining instructions from your end-point assessment organisation.
Delivery
Paper 1 and City & Guilds route papers 9289-301/302/303 are electronic; gas Paper 2 follows Awarding Body conditions.
Question style
Paper 1 and 9289-301/302/303 use four-option, single-correct multiple-choice questions. Gas integrated theory follows the accountable Awarding Body's rules.
Books and materials
Paper 1 and 9289-301/302/303 provide an in-platform calculator when calculation questions are present. Gas Paper 2 follows Awarding Body conditions.
| Paper | Coverage | Questions | Time | Grade boundary |
|---|---|---|---|---|
| Paper 1 — 9289-300 | Core knowledge for all routes | 60 | 120 minutes | Pass 36/60Distinction 50/60 |
| Paper 2a — 9289-301 | Air source heat pumps | 30 | 60 minutes | Pass 18/30 |
| Paper 2b — 9289-302 | Solar thermal | 30 | 60 minutes | Pass 18/30 |
| Paper 2 — 9289-303 | Non-domestic plumbing | 30 | 60 minutes | Pass 18/30 |
| Paper 2 — 9289-707/708 (integrated ACS theory) | CCN1 or equivalent theory tests and CENWAT or equivalent theory test | Set by the accountable Awarding Body | Set by the accountable Awarding Body | Pass Pass all applicable theory tests |
What to revise for ST0303
The current published Trade Exams library for this standard contains 500 original practice questions and 101 focused fact sheets. These are revision-library counts, not official exam weightings.
Knowledge-area map
Standard reference
ST0303
Core and route manifold
- T01Core safety, science and regulations
- T02Cold water, hot water and sanitation
- T03Heating systems and controls
- GasGas route
- EnvironmentalAir source heat pumps
- EnvironmentalSolar thermal
- Non-domesticNon-domestic plumbing
Core safety, science and regulations
01Safe systems, calculations, materials, information and compliance.
Cold water, hot water and sanitation
02Supply, storage, outlets, appliances, drainage and hygiene.
Heating systems and controls
03Heat sources, emitters, circulation, controls, commissioning and faults.
Gas route
04Public K19–K26 readiness for the integrated theory route; not a substitute for ACS training.
Air source heat pumps
05Heat-pump principles, design, installation and commissioning for paper 2a.
Solar thermal
06Solar-thermal components, controls, safety and commissioning for paper 2b.
Non-domestic plumbing
07Commercial systems, components, installation and testing for paper 9289-303.
How to prepare for the ST0303 test
A practical four-stage revision sequence: understand the rules first, close topic gaps, practise decisions, then rehearse under the real time pressure.
- 1
Confirm the apprentice's route and paper identifiers before building a revision plan.
- 2
Master core Paper 1 first because it applies across every option.
- 3
Practise reading original system diagrams and carrying out calculations with an on-screen calculator for Paper 1 and the City & Guilds route papers.
- 4
For environmental and non-domestic routes, complete 60-minute route papers after a full 120-minute core mock; gas candidates should use their Awarding Body's timing.
Revision access
Questions, mocks and fact sheets
One exam, one clear price. Access ends automatically and never renews into a subscription.
£10
30 days of access
Everything for this exam for 30 days.
One-off payment. No automatic renewal.
£20
90 days of access
Everything for this exam for 90 days.
One-off payment. No automatic renewal.
ST0303 exam questions answered
Format, timing, version, preparation and booking questions—answered from the recorded standard and assessment-plan sources.
01What is the ST0303 Plumbing and Domestic Heating Technician exam?
The ST0303 knowledge assessment checks the shared plumbing and heating knowledge required by every apprentice and the specialist theory for the occupational option recorded on their programme. All apprentices take core Paper 1: 60 four-choice questions in 120 minutes, with 36/60 required to pass. Gas-route apprentices also take integrated Paper 2 comprising the CCN1 or equivalent theory tests and the CENWAT or equivalent theory test; its conditions and marking are controlled by the accountable Awarding Body, and both papers must be passed. Environmental-route apprentices take both Paper 2a, Air Source Heat Pumps, and Paper 2b, Solar Thermal: 30 questions and 60 minutes each, with 18/30 required in each. Non-domestic apprentices take Paper 2, 9289-303: 30 questions in 60 minutes, with 18/30 required.
02Who should use this ST0303 revision page?
Apprentices registered to ST0303 version 1.2 on the gas, environmental technologies or non-domestic plumbing option.
03When do apprentices take the ST0303 knowledge test?
It is normally taken during end-point assessment, after the apprentice has completed training and passed through gateway. The employer, training provider and end-point assessment organisation agree the booking and sequence.
04What is the ST0303 exam format?
Core and route knowledge assessment. Paper 1 and City & Guilds route papers 9289-301/302/303 are electronic; gas Paper 2 follows Awarding Body conditions. Paper 1 and 9289-301/302/303 use four-option, single-correct multiple-choice questions. Gas integrated theory follows the accountable Awarding Body's rules.
05How many questions are there and how long does the test take?
60 core + 1 route paper and 120 min + route paper. Paper 1 — 9289-300: 60 questions, 120 minutes, pass 36/60. Paper 2a — 9289-301: 30 questions, 60 minutes, pass 18/30. Paper 2b — 9289-302: 30 questions, 60 minutes, pass 18/30. Paper 2 — 9289-303: 30 questions, 60 minutes, pass 18/30. Paper 2 — 9289-707/708 (integrated ACS theory): Set by the accountable Awarding Body, Set by the accountable Awarding Body, pass Pass all applicable theory tests.
06What is the ST0303 pass mark?
36/60 core + route paper. Paper 1 — 9289-300: pass 36/60; distinction 50/60. Paper 2a — 9289-301: pass 18/30. Paper 2b — 9289-302: pass 18/30. Paper 2 — 9289-303: pass 18/30. Paper 2 — 9289-707/708 (integrated ACS theory): pass Pass all applicable theory tests. Gas candidates normally complete the non-integrated assessment methods before the integrated methods. Existing ACS may provide an exemption only under the conditions in the EPA plan. Confirm the exact route and rules at booking.
07Is the ST0303 test open book?
Closed book (gas varies). Paper 1 and 9289-301/302/303 provide an in-platform calculator when calculation questions are present. Gas Paper 2 follows Awarding Body conditions.
08What subjects should I revise for ST0303?
The main areas are Core safety, science and regulations, Cold water, hot water and sanitation, Heating systems and controls, Gas route, Air source heat pumps, Solar thermal and Non-domestic plumbing. The detailed coverage on this page stays within the knowledge mapped to this assessment method.
09How should I prepare for the ST0303 exam?
Confirm the apprentice's route and paper identifiers before building a revision plan. Master core Paper 1 first because it applies across every option. Practise reading original system diagrams and carrying out calculations with an on-screen calculator for Paper 1 and the City & Guilds route papers. For environmental and non-domestic routes, complete 60-minute route papers after a full 120-minute core mock; gas candidates should use their Awarding Body's timing.
10Which version of ST0303 does this page cover?
This page uses the current ST0303 v1.2 EPA plan and the June 2026 City & Guilds 9289 provider information. Gas assessment settings remain controlled by the accountable awarding body.
11Are the Trade Exams questions official live exam questions?
No. Trade Exams' 500 practice questions and 101 fact sheets are independently authored revision material. They do not reproduce recalled, live, confidential or password-protected EPAO questions. The editorial bank covers the common core and all route families; an apprentice studies the core plus the selected option.
12Where do the ST0303 exam details come from?
The format and scope are based on the listed Skills England standard and end-point assessment sources, checked for this content pack on 2026-08-13. Always confirm late changes and booking instructions with the employer, training provider or EPAO.
13How does Trade Exams access work?
Access is a one-off £10 payment for 30 days or £20 for 90 days. It never renews automatically.
Official sources and currency
Check the standard behind this page
The format and scope were checked on 13 August 2026. Assessment arrangements can change, so confirm the final booking details with your employer, training provider or EPAO.
- Skills England ST0303 v1.2 standard
- Skills England ST0303 v1.2 EPA plan
- City & Guilds 9289 route and assessment documents
- City & Guilds 9289-12/15 Domestic Gas Provider and Employer Pack v2.1
- City & Guilds 9289-13 Environmental Provider Pack v1.1
- City & Guilds 9289-14 Non-domestic Provider and Employer Pack v1.1
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