Plumbing Repairs, Maintenance and Leak Detection
What the exam tests
This domain covers leak detection, isolation, repair methods, maintenance schedules and documentation. The exam expects a safe, systematic diagnosis rather than random dismantling.
Core rules
- First isolate and drain the affected section; lock/tag where required.
- Confirm the leak with the meter test: close all outlets and observe the water meter; movement indicates flow.
- Check visible joints, valve glands, traps and tank connections; use acoustic listening or section isolation for concealed lines.
- Repair with the correct method: replace a damaged section, use an approved clamp for a pinhole, rethread a damaged end, or re-solvent-weld plastic.
- Support the repaired pipe and test at working pressure before restoring service.
- Record the fault, parts used and test result.
Worked example
A meter runs with all taps closed. Isolate the internal distribution and observe: if the meter stops, the leak is downstream. Isolate branches one by one; the branch that stops the meter contains the fault. Listen at walls and check damp patches, then open the smallest area needed and repair with a slip coupling. Reason: section isolation narrows the search before breaking finishes.
Traps
Opening a live line; repairing without isolating; using an unapproved clamp on a high-pressure line; not drying a solvent joint; ignoring water hammer; no retest.