If you’re thinking about installing a solar hot water system in Queensland, you’ve probably heard about booster systems. But do you really need one? And what happens if you don’t have it?

The short answer: yes — you absolutely need a booster. In this article, we’ll explain how solar hot water systems work, when boosters kick in, and what Queensland homeowners should know to stay out of cold water.

1. What Is a Booster and Why Is It Needed?

A booster is a secondary heat source — usually electric or gas — that heats your water when the sun isn’t enough. It ensures you still get hot water during:

• Overcast or rainy days
• Early mornings or late nights
• Winter months with shorter daylight
• Periods of high demand (extra showers, laundry, etc.)

Without a booster, your solar system may not deliver consistent hot water, especially during peak-use times or cloudy periods.

2. Types of Boosters: Electric vs Gas

Electric Boosters

• Common in all-electric homes
• Automatically heats water when solar input is low
• Lower upfront cost
• Slightly higher running cost depending on tariff

Gas Boosters

• Preferred in homes with existing gas supply
• On-demand heating
• Fast, efficient, and typically lower running cost
• Higher initial install cost if gas isn’t already connected

We recommend gas boosters for households with continuous-flow needs or when transitioning off-grid solar systems.

3. How Do Boosters Work with Solar?

Most systems use a thermostat or sensor to monitor water temperature. If the water hasn’t reached the required level (typically 60°C for health compliance), the booster automatically kicks in.

You can also choose between:

• Manual Boosting: Gives you control over when to activate the booster
• Automatic Boosting: System turns it on only when needed

In Queensland, automatic boosters are more common, and preferred for compliance and convenience.

4. Do All Solar Systems Require a Booster in QLD?

Yes — under Queensland plumbing regulations, a compliant solar hot water system must be able to deliver reliable hot water year-round. That means a booster is required.

It’s also a safety standard. Hot water must reach at least 60°C to prevent bacterial growth (like Legionella). Without a booster, you can’t guarantee that temperature on cloudy days.

5. How to Tell If Your Booster Isn’t Working

Common signs include:

• Water that stays lukewarm during winter
• Cold morning showers even after sunny days
• System fault lights or error codes
• Hot water only after long sun exposure

What to do:
If your system is underperforming, it may be a booster fault — not the panels.
➡️ Book a system check with our team

6. How Often Should Boosters Be Serviced?

We recommend servicing your solar system and booster every 2–3 years, or sooner if:

• The system is over 5 years old
• You’re experiencing inconsistent temperatures
• You’ve never had the anode rod or valve checked

Regular maintenance prevents breakdowns and ensures your booster activates when needed.

7. How Boosters Affect Your Power Bill

A properly installed and functioning booster has minimal impact on your bill — especially when compared to electric-only systems.

To minimise booster usage:

• Install a timer (for manual boosters)
• Use hot water during daylight hours
• Insulate pipework to reduce heat loss

8. Need Help With a Solar Booster System?

We supply, install and service solar hot water systems with boosters across Caboolture, Moreton Bay and North Brisbane. If you’re unsure whether your booster is working — or which booster is right for your setup — we can help.

➡️ Talk to a licensed solar plumber today
➡️ Compare full replacement costs and system types here

FAQs

Can I turn my booster off to save power?
Yes, but only if your system allows manual control. Be cautious — cold water risks increase without proper monitoring.

What temperature should hot water reach?
At least 60°C for storage systems. This is a legal and health standard in QLD.

Can I add a booster to an existing solar system?
Yes, we can retrofit boosters onto compatible systems or upgrade to a new model with integrated control.