An outdoor hot water cylinder works well for many New Zealand homes where internal space is tight or a renovation creates a chance to relocate the system. However, not every cylinder suits outdoor installation, and the job involves more than simply moving the unit outside.
This post covers when an outdoor hot water cylinder makes sense, what types work, and what needs assessing first.
Is an Outdoor Hot Water Cylinder a Good Option?
Outdoor cylinder installations are becoming more common in New Zealand. MBIE building guidance notes that cylinders are now sometimes installed outside to save space, and several leading manufacturers produce models specifically rated for outdoor use.
Reasons homeowners go outside include freeing up a hot water cupboard, using available exterior wall space, or fitting a heat pump system suited to outdoor placement.
Not every cylinder suits outdoor use. Standard low pressure copper cylinders carry an indoor-only rating. Installing one outside voids the warranty and creates compliance issues under the NZ Building Code.
What Types of Outdoor Hot Water Cylinder Are Available?
Cylinders that suit outdoor installation in New Zealand include the following.
Mains pressure indoor/outdoor enamel cylinders Several mains pressure enamel models from manufacturers such as Rinnai carry ratings for both indoor and outdoor use. These handle outdoor conditions well and comply with Building Code clause G12.
Heat pump hot water systems Many heat pump hot water systems are purpose-built for outdoor placement. Integrated heat pump cylinder units suit New Zealand residential properties well, and outdoor is often the standard configuration for these systems.
Moving an existing cylinder outside If you have an existing indoor cylinder and want to move it outside, your plumber needs to confirm whether it carries an outdoor rating. Without one, you will need a replacement outdoor-rated model.
What Does Your Plumber Need to Assess?
Your plumber will assess several things before recommending an outdoor installation.
Cylinder rating The cylinder must carry an outdoor rating from the manufacturer. An indoor-only unit placed outside creates both warranty and compliance problems.
Pipe runs and insulation Pipe runs from an outdoor cylinder to internal outlets can be longer, which affects heat loss. Building Code requirements call for hot water pipe insulation, and this matters more for outdoor installations.
Location and access Location on the property needs to suit the existing plumbing layout. Easy access for future maintenance is also worth factoring in.
Trades required A licensed plumber handles the plumbing connections and a registered electrician handles the electrical work. GoFox can coordinate both trades and ensure the full job meets NZ Building Code standards.
The team at GoFox can assess your existing setup, confirm whether an outdoor installation suits your property, and recommend the right cylinder for the job. Visit our hot water cylinders service page to find out what we cover.
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Frequently Asked Questions
Can I install a hot water cylinder outside? Yes, provided the cylinder carries an outdoor rating from the manufacturer. Several mains pressure enamel models and most heat pump hot water systems suit outdoor installation. Standard low pressure copper cylinders do not.
Do outdoor hot water cylinders need special installation? Yes. Pipe insulation is particularly important for outdoor installations, and the location needs to suit your plumbing layout. A licensed plumber and registered electrician are both required.
Will an outdoor cylinder increase my energy costs? Longer pipe runs can increase heat loss if insulation is not installed correctly. A well-planned outdoor installation with properly insulated pipework should not significantly affect running costs.
Can I move my existing hot water cylinder outside? Only if it carries an outdoor rating. Most standard indoor cylinders do not. Your plumber can check the rating and advise whether the existing unit can be relocated or whether a replacement is needed.
How do I know if an outdoor installation suits my property? A GoFox plumber can assess your property, check your existing system, and recommend the best approach. Contact your local GoFox team for an assessment and quote.
