22 January 2026

Replacing your hot water cylinder isn’t something you do every day. In fact, research shows us that nearly all homeowners don’t even think about this until it breaks down. But when the time comes, it’s a great opportunity to upgrade to something more efficient, sustainable, and future-ready.

Here are six questions to ask your plumber to make sure you’re getting the best solution for your home and lifestyle.

1. Is it time to upgrade to mains pressure?

If you’re still on a low pressure system, you might be missing out on better water flow and modern tapware compatibility. Ask your plumber if your home is suitable for Rheem’s new All Pressure® electric water heaters – these are designed to work with any pressure system and make upgrading to mains pressure easy.

2. Would a heat pump water heater work for my home?

Heat pump water heaters use ambient air to heat water, making them incredibly energy-efficient, and a great choice for sustainability-minded households. Rheem AmbiPower® and Ambiheat® heat pump hot water heaters are suitable for all NZ climates, as they will still generate heat from the atmosphere, even when the temperatures drop down to minus 5 degrees Celsius.

3. What size cylinder do I need?

Your household size, water usage habits, and future plans (like a growing family or renovations) all affect the ideal cylinder size. Ask for a recommendation based on your current and future needs, or use the Rheem Product Selector guide. Rheem has a wide range of sizes to suit Kiwi households of all sizes.

4. Where should the new cylinder go?

Sometimes it makes sense to relocate your cylinder, especially if you’re switching to a heat pump, which will need outdoor space. Rheem AmbiPower® and Ambiheat® heat pump hot water heaters are ideal for replacing outdoor mains pressure electric cylinders and outdoor gas continuous flow units. Ask your plumber about the best location for performance, noise, and access.

5. What are the running costs and energy savings?

Not all water heaters are created equal. A more efficient system might cost more upfront but save you money in the long run. Ask for a comparison of running costs between your current system and a Rheem heat pump or All Pressure™ upgrade, or refer to the EECA and Genless sites for more information. Heat Pumps can reduce your water heating energy costs by up to 70% (about a third of your total power bill), so they may well be the smart choice for you and your household!

6. What kind of warranty and support comes with it?

It’s essential to check your water heater’s warranty period before you make your selection. As water heaters are such well-used appliances in most households, you need to make sure you understand what’s covered and who to call if something goes wrong. Rheem products come with strong warranties and nationwide support, so you’re never left in the cold (water). Our customer service and after sales teams are based in our Auckland office, and are always ready to answer any questions you might have!

In short, don’t be afraid to ask questions – a good plumber will be happy to walk you through your options and give you the best water heater recommendation based on your specific situation. On that note, when it comes to quality, efficiency, and innovation, Rheem has been trusted by Kiwi homeowners for generations. Whether you’re replacing a tired old cylinder or planning a more energy-efficient future, Rheem has a solution to suit your home.

Replacing your hot water cylinder isn’t something you do every day