At GridFree, we know that going off-grid doesn’t mean compromising on comfort. And few things are as essential to off-grid living as reliable, efficient hot water. That’s why our GridFree Connections series exists: to connect our community with the best off-grid-friendly businesses across New Zealand. These visits are all about reducing the obstacles to off-grid living, offering recommendations we trust.
This month, our team visited Spiroloc in Christchurch — a proudly local, family-run manufacturer that became popular over the past years in our off-grid community, for creating robust, innovative off-grid water heating solutions.
Meet Paul from Spiroloc
We were warmly welcomed by Paul, who runs the company founded by his father, Alastair — affectionately described as a bit of a “mad scientist” with a passion for invention. What started in the 1970s with one spiral ducting machine has now become a go-to workshop for everything from custom flues to industrial boiler systems.
But it’s Spiroloc’s growing range of wood-fired water heaters that caught our eye. From bath heaters and spa heaters to solutions for hot tubs and swimming pools, Spiroloc has developed a simple, safe, and incredibly efficient way of heating water with fire, making it a brilliant fit for off-grid applications.
Why Wood-Fired Hot Water Makes Sense Off-Grid
As we explored in our blog post “What Are the Best Methods to Heat Water Off-Grid?”, electric water heating is one of the biggest power draws on any system, which makes it challenging to run directly off solar unless you’re heavily overpowered. That’s why alternative solutions, especially wood-fired options, are not just viable but also smart.
Spiroloc’s water heaters offer an excellent way to sidestep the energy drain and still enjoy hot water year-round. Whether you’re heating a spa pool on a remote block or just want a dependable, no-frills hot water system that doesn’t tax your batteries, their range ticks all the boxes.
Craftsmanship You Can Count On
One thing became clear as we toured the workshop, Spiroloc doesn’t cut corners. Every flue, every heater, and every duct is custom-made on-site, often using locally sourced materials. They’re big believers in durability, and they back their builds so strongly that they don’t even offer a standard warranty—because issues rarely happen, and if they do, Paul wants to hear about it himself.
You’re not calling a call centre — you’re talking directly to the people who made your product (just like here at GridFree).
What Not to Run on Solar — And What to Use Instead.
Our blog “What Not to Run on Solar and What to Use Instead” highlights the importance of smart substitutions for high-power appliances. Water heating is at the top of that list — and Spiroloc’s wood-fired heaters are a textbook example of the kind of off-grid swap that can dramatically improve the performance and lifespan of your solar setup.
Local, Passionate, and Purpose-Built.
Spiroloc isn’t just a manufacturer — they’re a team that deeply cares about the people they’re building for. Paul and his crew are proud to make gear that stands up to New Zealand conditions, meets the real needs of off-grid families, and supports a lifestyle of resilience, independence, and simplicity.
Final Thoughts from GridFree.
Our visit to Spiroloc left us impressed and inspired. Their values — quality, practicality, and community — align beautifully with our mission at GridFree. We're proud to recommend them as a trusted supplier for anyone looking to upgrade their off-grid water heating without overloading their solar system.
Stay tuned for more from the GridFree Connections series as we continue to explore the people and products powering the off-grid lifestyle across Aotearoa.
Interested in off-grid water heating? Check out our recommended off-grid hot water solutions, visit Spiroloc.co.nz to learn more about their range.