How to tell a good solar heater from a bad one

Not all solar heaters are equal, even when they look similar on the roof. The difference between a heater that lasts for years and one that starts having problems within a season or two often shows in details that aren't obvious at first glance. This checklist gives you things to verify yourself before deciding.

1. The tank: insulation and material

Ask about the tank material and insulation thickness. Good insulation is what keeps water hot for long hours with minimal heat loss, especially overnight. Ask to see the tank yourself during the inspection, not just take someone's word for it.

2. The panels: glass and build quality

Panels exposed to weather (sun, heat, dust) need to hold up, so glass and build quality affect lifespan. A heater with weak panels starts losing efficiency quickly.

3. Is there a magnesium anode?

Ask directly: is there a magnesium anode inside the tank? It's what protects the tank from scale and rust long-term. Its absence is a red flag. (Full details in Solar water heater installation & maintenance.)

4. Is the warranty written and specific

A real warranty is written in an invoice or contract, and states exactly what it covers (the tank? the panels? the backup element?) and for how long. A vague or verbal-only answer is a negative signal.

5. Does the backup electric element work correctly?

Confirm there's an automatic backup element that kicks in when the sun is low (winter and cloudy days) — otherwise you'll be without hot water often.

So how do I actually check?

The easiest way: ask to see the tank and panels in person during the inspection, and ask these five questions directly. Book a free inspection or find your right capacity for your home.