Decide the type before the make
A badge on the side tells you who built the unit. It tells you nothing about whether an electric cylinder, a heat pump, gas continuous flow (often called a califont), solar or a wetback is right for your home.
That choice turns on your energy supply, the room you have, and whether your hot water runs at low pressure or mains pressure. Start with the types compared and what size cylinder you need, then come back to the brands.
What to compare between makes
- What the warranty says about installation. Rheem and Rinnai both exclude failures that trace back to installation done outside their instructions or the rules.
- The date the warranty counts from. Both makers tie it to installation, so the invoice with the install date is worth keeping with the owner's guide.
- How long the cover runs. Rheem says terms vary from model to model, so read the guide for the exact unit on the quote, not a brochure.
- What sits outside the warranty. Rinnai, for one, says servicing isn't covered.
- Who can look after it. Ask whether tradies near you fit and repair that make, and how quickly parts arrive.
Questions to ask about any make
- Which exact model is on the quote, and can I read its owner's guide before you order it?
- What does the warranty exclude, and what would void it?
- Does this cylinder have an anode, and what does the guide say about checking it?
- How often do you install this make, and who services it if it fails?
- Will the installation follow the maker's instructions as well as the Building Code?
Why there are only two guides so far
We write a brand guide only after reading that maker's own New Zealand pages and warranty papers. So far that's Rheem and Rinnai. If a tradie quotes another make, the questions above still work: ask for its owner's guide and the warranty terms in writing.
We haven't found independent failure rates for hot water brands that we'd trust, so we don't rank them. The person who installs the cylinder matters as much as the badge, because both warranties lean on correct installation. That's why we match each job with an authorised local tradie who works on hot water cylinders.