Gravity Feed Hot Water Systems: How They Work, Benefits & Installation Guide

Oct 3, 2024

Looking for a gravity feed hot water system? This complete guide explains how these systems work, why they’re ideal for off-grid and low-pressure homes, and how to keep them running efficiently. We’ve also included expert tips on installation, safety, and comparisons with modern systems.

Key Takeaways

  • ✅ Gravity feed hot water systems are energy-efficient and pump-free, lowering energy bills.

  • ✅ Perfect for older or off-grid homes, thanks to their low-maintenance setup.

  • ✅ Keep hot water flowing even during power outages.

  • ✅ Installation height and proper maintenance are critical for performance.


What Is a Gravity Feed Hot Water System?

A gravity feed system uses elevation—not electricity—to move hot water. A tank placed on your roof or in your attic stores water that flows down to taps and showers by the force of gravity.

How it works:

  1. Cold water fills the storage tank.

  2. The tank heats water using a gas or electric element.

  3. Hot water flows downward when taps are opened.

  4. Water pressure depends on how high the tank sits above your fixtures.


Advantages of Gravity Feed Systems

1. Energy Efficiency & Cost Savings

  • 🚫 No pump = no energy consumption for circulation.

  • 💸 Lower operational costs than pressure systems.

  • 🌿 Great for solar integration with minimal energy loss.

Explore our energy-saving solar hot water systems.

2. Low Maintenance & Longevity

  • Fewer moving parts = fewer things to break.

  • Ideal for homes with existing gravity plumbing.

  • Tank maintenance is simple and infrequent.

3. Reliable During Power Outages

  • Gravity keeps the water flowing—even when the grid goes down.

  • A dependable solution for rural and off-grid homes.

4. Flexible Tank Sizes

5. Compatible with Solar Heating

  • Boost efficiency by pairing your gravity feed system with roof-mounted solar panels.


Installation Considerations

1. Elevated Tank Position

Install the tank 2–3 metres higher than your highest fixture. Ideal spots include:

  • Roof cavities

  • Attic spaces

  • Roof-mounted platforms

2. Insulation & Pipe Design

  • Insulate all hot water pipes to retain heat.

  • Install a tempering valve to prevent scalding.

3. Professional Installation

Hiring a licensed plumber ensures:

  • Proper elevation for water pressure.

  • Leak-proof pipework.

  • Australian Standards compliance.

Need expert help? Book a licensed plumber here.


Gravity Feed vs. Mains Pressure Systems

Feature Gravity Feed Mains Pressure
Water Pressure Based on tank height Consistently high
Energy Use Minimal Moderate to high
Maintenance Low Moderate
Best For Off-grid/older homes Modern high-demand homes

Bottom Line: Choose gravity feed if you prefer reliability, lower bills, and minimal complexity.


Maintenance Tips

Inspect annually – Check insulation, leaks, and fixtures.
Flush tank every year – Removes sediment and improves performance.
Replace anode rod – Extend your tank’s life by monitoring corrosion.
Check pressure relief valve – Prevents dangerous pressure build-up.

For long-lasting performance, schedule professional servicing every 3 years.


Safety Measures

  • 🧼 Prevent bacterial growth – Keep tank temperature above 60°C.

  • 🚿 Tempering valves – Lower outlet temp to 50°C for safety.

  • 👶 Child-safe bath temps – Keep at 37–38°C for safe use.

If unsure, speak to JR Gas & Water about safe installation practices.


Energy Efficiency & Solar Boosting

  • 🌤️ Combine your gravity system with a solar hot water booster for maximum energy savings.

  • ⚡ Run heaters during off-peak electricity times for further cost savings.


Why Choose JR Gas & Water?

  • 🛠️ Brisbane-based hot water experts

  • 🔥 Fully licensed plumbers & gas fitters

  • 🏆 Voted Best Plumbers & Best Home Care Store in 2023, 2024, and 2025

  • 💬 Easy online quote requests


Frequently Asked Questions

1. How does a gravity feed system work?
It uses gravity to move heated water from a high storage tank to your taps—no pump needed.

2. How do I maintain one?
Flush the tank yearly, check for leaks, and inspect the anode rod and relief valves regularly.

3. Is it better than mains pressure?
If you live off-grid or want low maintenance and reliable water flow during outages—yes.

4. What tank size is ideal for a home?
A 250L–315L system is typically enough for 4–5 people.

5. Is it safe?
Yes—with a tempering valve and regular servicing, it’s just as safe as other systems.


Final Thoughts

A gravity feed hot water system is a smart, sustainable, and budget-friendly solution—especially for off-grid homes or older properties in Southeast Queensland. JR Gas & Water provides full-service installations, upgrades, and maintenance support so you can enjoy reliable hot water with peace of mind.

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