Quick answer: Water & Gas Worx supplies and installs the full range of electric hot water cylinders across Auckland — Rheem Mains Pressure, Rheem Optima outdoor, Rheem Low Pressure copper, and Rinnai Enamel. Prices start from $2,499 incl GST fully installed, including the unit, removal of your old cylinder, plumbing and electrical connections, and warranty registration. Installed by Peter — licensed plumber with 17+ years experience. Call 0800 322 322.
Models We Supply & Install
Five electric cylinders cover 95% of Auckland replacement jobs. The right one for your home depends on your existing setup, household size, and whether the unit lives indoors or out.
Rheem Low Pressure 135L
Copper-lined low pressure cylinder for gravity-fed homes with a header tank. Reliable direct swap for older Auckland homes built before 1990. Suits 1–2 people.
Rheem Mains Pressure 180L
Vitreous enamel tank, 3 kW element, 10-year cylinder warranty. The go-to replacement for older indoor mains pressure cylinders. Suits 3–4 people.
LP to Mains Conversion
Upgrade from low pressure to full mains pressure hot water. New cylinder, pipework modifications, pressure testing — done in a day. Suits any household.
Rinnai Enamel 180L
Rinnai's vitreous enamel outdoor electric cylinder. Strong warranty, slim footprint, built to handle Auckland's coastal conditions. Suits 3–4 people.
Rheem Optima 180L
Outdoor-rated mains pressure cylinder with weatherproof jacket. Perfect for external wall installs where indoor space is tight. Suits 3–4 people.
Rheem Optima 300L
The largest outdoor-rated electric cylinder in the Rheem range. Built for large families and homes with multiple bathrooms. Suits 5+ people.
The Electric Hot Water Cylinder Range
An electric hot water cylinder heats and stores water using an immersion element inside the tank. Cold water enters the base, the element warms it, and heated water is drawn off the top to your taps and showers. Electric cylinders are simple, reliable, and the most common hot water system in older Auckland homes.
We supply and install the full Rheem and Rinnai electric cylinder range — from compact 135-litre low pressure copper cylinders for bach and rental properties, through to 300-litre outdoor-rated Optimas for large families. Every unit is installed by a licensed plumber, wired by a registered electrician, and covered by the full manufacturer warranty.
Mains Pressure vs Low Pressure — Which Do You Have?
Quick Check
Low pressure — if you have a small tank sitting in the ceiling space or on a platform above the cylinder, you are on a low pressure (gravity-fed) system. Shower flow is weak, and running two taps at once cuts the pressure further. Most Auckland homes built before 1990 are low pressure.
Mains pressure — if your cold and hot water run at the same pressure (strong shower, no header tank in the roof), you are on a mains pressure system. Modern homes and any home renovated since 2000 are almost always mains pressure.
Replacing a low pressure cylinder with another low pressure cylinder is a simple direct swap. Upgrading from low pressure to mains pressure involves removing the header tank, replumbing the hot water lines, and often upgrading taps and tempering valves — but the difference in shower performance is dramatic. We quote both options so you can weigh them up properly. See our low pressure to mains conversion guide for the full detail.
Vitreous Enamel vs Copper
The two main cylinder materials on the market today are:
- Vitreous enamel — a glass-fused steel tank with a sacrificial anode inside to prevent rust. Used in the Rheem Mains Pressure and Rinnai Enamel ranges. Tough, long-lasting, and the standard choice for modern mains pressure systems. 10-year cylinder warranty.
- Copper — traditional copper-lined tanks, still used in low pressure cylinders like the Rheem Low Pressure 135L. Copper naturally resists corrosion and is lighter than enamel, which is why it has been the standard low pressure material for decades.
Both materials are proven and reliable when installed correctly. The cylinder type you need is usually dictated by your existing system rather than a free choice — replacing a copper low pressure with enamel mains pressure is a bigger job than a like-for-like swap.
Installation — What's Included
Every electric cylinder installation from Water & Gas Worx includes:
- Full supply of the new cylinder and all fittings
- Removing and disposing of your old cylinder
- Installing the new cylinder in the same position (like-for-like)
- Connecting hot and cold water lines with new isolation valves
- Installing or replacing the tempering valve and pressure limiting valve
- Electrical connection by a registered electrician
- Filling, testing and commissioning the unit
- Registering the manufacturer warranty on your behalf
- Certification in line with PGDB requirements
Most replacements are completed in a single visit — typically 3 to 5 hours start to finish. If your cylinder has failed and you have no hot water, we offer same-day installation on common models when you call before 9am.
Signs It's Time to Replace Your Electric Cylinder
- Age — most electric cylinders last 10–15 years. Over 12 years, start budgeting for replacement regardless of how it looks.
- Water pooling at the base — the tank is leaking and cannot be repaired.
- Rusty or discoloured hot water — the internal tank or anode is breaking down.
- Element keeps tripping the breaker — the element has shorted and the tank may be about to leak.
- Running out of hot water mid-shower — thermostat or element failure.
- Loud popping or rumbling — sediment buildup reducing efficiency and hammering the element.
For the full electric cylinder range and pricing, visit wgw.co.nz/hot-water/cylinders/electric
Frequently Asked Questions
How much does an electric hot water cylinder cost installed in Auckland?
Rheem Low Pressure 135L copper cylinders start from $2,499 installed. Rheem Mains Pressure 180L vitreous enamel cylinders start from $3,499 installed. Outdoor-rated units like the Rheem Optima 180L/300L and Rinnai Enamel 180L range from $4,099 to $4,999 installed. All prices include supply, installation, removal of the old unit, and certification.
What is the difference between mains pressure and low pressure cylinders?
Mains pressure cylinders deliver hot water at the same pressure as your cold water — full flow at every tap. Low pressure cylinders are gravity-fed from a header tank in the roof and deliver hot water at much lower pressure. Most Auckland homes built before 1990 use low pressure systems.
Can I replace a low pressure cylinder with a mains pressure cylinder?
Yes, but it requires additional work. Upgrading from low pressure to mains pressure means removing the header tank, replumbing the hot water lines to handle mains pressure, and often upgrading taps or tempering valves. It is a worthwhile upgrade — mains pressure gives you dramatically better shower flow — but it is more involved than a like-for-like swap.
How long does an electric hot water cylinder last?
A good quality electric cylinder lasts 10 to 15 years. Vitreous enamel cylinders like the Rheem Mains Pressure come with a 10-year cylinder warranty. Copper low pressure cylinders typically last 15 to 20 years.
How long does an electric cylinder installation take?
A standard like-for-like electric cylinder replacement takes 3 to 5 hours. We aim to complete most installations in a single visit so you have hot water again the same day.
What size electric cylinder do I need?
For 1 to 2 people, a 135-litre cylinder is usually enough. For 3 to 4 people, go with 180 litres. For 5 or more people, a 250 to 300 litre cylinder is the right choice.
Do I need a certified plumber to install an electric hot water cylinder?
Yes. Hot water cylinder installation in New Zealand must be carried out by a licensed plumber registered with the Plumbers, Gasfitters and Drainlayers Board (PGDB). Electrical connection also requires a registered electrician.
Should I consider a heat pump hot water system instead?
If you are replacing a failed electric cylinder and are open to running costs savings, yes — heat pump hot water systems cost around a third of an electric cylinder to run. Upfront cost is higher ($6,399–$8,299 installed) but the savings pay the difference back within 4–6 years for most households. See our integrated heat pump range.
