Planning a Solar Geyser: Thermal, PV and the Installation Brief

By HWS Plumbing editorial team · Published 11 November 2026

Before requesting a solar geyser quote, establish whether you mean a solar thermal water heater or a geyser powered through solar photovoltaic electricity. They use the sun in different ways and have different installation and authorisation considerations. A good brief describes your household’s hot-water needs, existing equipment and property, then asks for a system-specific assessment rather than a generic package.

Use the correct description from the start

The City’s going-solar guide distinguishes solar thermal water heaters from PV-powered geysers. It states that thermal water heaters do not need electricity-generation authorisation, while PV geyser systems follow the relevant authorisation route. That distinction does not remove other installation requirements. Explain which technology you are considering and ask the relevant professionals to confirm the requirements for the proposed system. Do not assume that an existing solar electricity installation automatically covers every later change.

Describe the household rather than guessing a capacity

Tell the installer how many people use hot water, the main times of demand and whether the property is occupied all year. Include baths, guest accommodation and planned additions where relevant. A system that suits one household may not suit another with a different routine. If the current system runs short, state when that happens. If it has a fault, distinguish the fault from the desired improvement so both can be assessed.

Look at the roof and the routes together

Roof space, shading, access and the building’s construction can affect what is suitable. Pipe routes and the position of the storage arrangement matter too. Provide photographs from safe ground-level positions and existing plans if available; do not climb onto a roof for a quotation picture. Ask who assesses the building-related requirements and what is included in that assessment. The final design should reflect the actual property, not only the appearance of equipment in a brochure.

Ask how the system works when conditions change

Discuss how the chosen arrangement meets demand during less favourable conditions and what controls or supplementary heating it uses. Ask how occupants will operate it and which settings are intended for routine use. Avoid assuming that solar means no electrical input or identical performance on every day. The explanation should cover the complete system and your usage pattern. Keep the manufacturer’s instructions so the handover remains useful after the initial demonstration.

Put the paperwork and exclusions on the quote

The City provides guidance for approval of newly completed or altered water installations. Ask who handles the applicable forms, inspection coordination and any separate electrical documentation. Make sure the proposal distinguishes equipment, plumbing alterations, roof-related work and other trade responsibilities. Confirm how unforeseen conditions are authorised and what is excluded. This is especially useful for older installations where the surrounding pipework may need attention alongside the new equipment.

Plan ownership after installation

Keep model details, manuals, invoices and warranty conditions together. Ask about servicing access and the practical checks an owner should make without opening equipment. If a problem develops, a clear record helps describe the installed arrangement. HWS Plumbing assists with solar geyser installations and heat-pump services. For Gordon’s Bay and surrounding areas, send us your project details so the property, hot-water needs and proposed work can be discussed before equipment is selected.

Common questions