Level 3 · Plumbing revision

Hot Water revision notes

System selection, demand and storage sizing, reheat times, scald protection and fault diagnosis.

System Selection & Design

Trade-offs between heating water on demand and storing it in a cylinder.

Keeping hot water close to distant outlets, and how solar and heat-pump cylinders differ.

How open-vented and unvented stored hot water systems differ and what drives the choice at Level 3.

Turning a coil or element power rating into how long a cylinder takes to recover.

Applying Q = m x c x change in T to find the energy and time to heat stored water.

A structured way to estimate daily and peak hot water demand and pick a storage volume.

Why hot water is stored at 60 °C, distributed hot, and how dead legs are limited.

How TMVs deliver safe outlet temperatures while storage stays hot, including the 48 °C bath limit.

The operational checks and documentation needed to bring a hot water system into safe service.

A systematic approach to common stored hot water defects and how to reason from symptom to cause.

What to demonstrate and hand over to the user, and how manufacturer schedules drive servicing.

Routine measures and record-keeping that keep stored hot water safe from bacterial growth.

Every module has its own revision notes and question bank.