Why Your Solar Hot Water System Might Stop Heating (And What You Can Do About It)

Waking up to a cold shower? If your solar hot water system has stopped heating, it can be frustrating — especially in the cooler months when you need it most. The good news is that not all issues mean your system is broken. Some are quick fixes, while others may require a professional touch.

At Todd’s Plumbing & Electrical, we’ve been servicing solar hot water systems across the Gold Coast for over 20 years. Here’s a look at the most common reasons your system might not be producing hot water — and what to do about it.

1. Not Enough Sunlight or Poor Positioning

Solar systems rely on the sun, so cloudy weather, shade from trees, or poor panel placement can reduce heating performance.
What to look for: Cold or lukewarm water after multiple cloudy days.
What to do: Wait for a sunny day or consider trimming overhanging trees. If shading is an ongoing issue, a booster system may help.

2. Booster System Not Working

Most solar hot water systems have an electric or gas booster to help heat water during cloudy days or overnight. If your booster isn’t working, you may not get hot water at all.
What to look for: Cold water even after several sunny days, especially in winter.
What to do: Check if your booster switch is turned on. If it is and still not working, call a licensed plumber or electrician.

3. Faulty Thermostat or Element

Like any hot water system, solar units can suffer from electrical faults — including failed heating elements or faulty thermostats.
What to look for: Inconsistent water temperature or water that won’t heat at all.
What to do: These components should be tested and replaced by a qualified technician.

4. Circulation Pump Problems (for Split Systems)

In split-system solar heaters, a pump moves water between the panels and the storage tank. If this pump fails, water won’t circulate — and won’t heat.
What to look for: Panels feel cold during the day or no sound from the pump.
What to do: A plumber can check for pump failure or a faulty controller.

5. Airlocks or Blockages

Air trapped in the system or sediment buildup in pipes can prevent water from circulating properly, reducing efficiency.
What to look for: Gurgling sounds, reduced water pressure, or system making odd noises.
What to do: A professional flush or inspection may be needed to clear blockages or bleed air.

6. Damaged or Dirty Solar Collectors

If your solar panels are cracked, dirty, or damaged, they won’t absorb sunlight effectively — meaning less heat for your water.
What to look for: Visible dirt or cracks on panels, or very slow heating.
What to do: Clean the panels carefully or call a technician to inspect for damage.

Get Your Hot Water Flowing Again

No one wants to go without hot water — and with regular servicing, most solar hot water problems can be prevented. If your system has stopped heating, let the experts at Todd’s Plumbing & Electrical take a look.

We provide fast, reliable service across the Gold Coast, and we’ll get your hot water back on in no time — with honest advice and no hidden surprises.

📞 No hot water? Call Todd’s Plumbing & Electrical on 0482 080 423 — your Gold Coast solar hot water specialists.