Quick answer: Water & Gas Worx supplies and installs gas continuous flow hot water systems across Auckland — Rinnai Infinity and Rheem Integrity. A straight swap starts from $2,199 incl GST, cylinder-to-continuous-flow conversion from $3,599 incl GST. Every installation includes the unit, gas pipework, gas compliance certificate, electrical coordination, and removal of your old system. Installed by Peter — licensed plumber and certifying gasfitter. Call 0800 322 322.
Models We Supply & Install — Full Conversion
The prices below are for a full conversion — typically switching from an old electric hot water cylinder to a brand-new gas continuous flow unit. That covers removal of the old cylinder, new gas line and connections, external mounting, commissioning and gas certification.
Both units below are excellent — flow rate, efficiency and warranty are near identical. Which one you pick usually comes down to which brand you trust.
Rinnai Infinity A26
New Zealand's best-selling continuous flow unit. 26 L/min at 25°C rise, 44.5 kW output, electronic ignition, frost protection standard. Made in Japan. 10-year heat exchanger warranty.
Rheem Integrity 27
Rheem's flagship continuous flow unit. 27 L/min at 25°C rise, 205 MJ/h input, 6-star energy rating, frost protection to −20°C. Made in Japan. 10-year heat exchanger warranty.
Endless Hot Water, No Tank
A gas continuous flow hot water system heats water only when you turn on a hot tap. There is no storage tank — cold water passes through a heat exchanger, the burner fires, and hot water comes out at a constant temperature for as long as you want it. Run a shower for an hour, and the last minute is the same temperature as the first. No tank to reheat, no standing losses, no running out during back-to-back showers.
Two units dominate the New Zealand continuous flow market — the Rinnai Infinity A26 and the Rheem Integrity 27. Both deliver 27 litres per minute, both use electronic ignition (no pilot light), both mount externally on the wall. Water & Gas Worx supplies and installs the full range across Auckland — conversions from cylinders, straight swaps of old units, and new-build installs.
Why Gas Continuous Flow?
- Endless hot water — the heat exchanger fires as long as you run the tap. No waiting for a cylinder to reheat, no cold shower at the end of a busy morning.
- Compact outdoor install — the unit mounts on an external wall. No indoor cupboard, no floor space lost, no flue through your ceiling.
- Electronic ignition — modern continuous flow units fire on demand. No wasted gas keeping a pilot lit 24/7.
- Energy efficient — 6-star MEPS rating on both A26 and Integrity 27. You only heat the water you actually use.
- Long lifespan — heat exchangers are rated for 15+ years and both units come with a 10-year heat exchanger warranty backed by the manufacturer.
- Temperature controller ready — wired room controllers let you set exact shower temperature and pre-set kitchen tap flow.
Installation — What's Included
Every gas continuous flow installation from Water & Gas Worx includes:
- Full supply of the new Rinnai A26 or Rheem Integrity 27
- Removing and disposing of the old unit (if replacing)
- Wall-mounting the new unit on the existing or new bracket
- Connecting the gas line with a new isolation valve
- Connecting hot and cold water with isolation valves and tempering valve
- Wiring in the temperature controller (if fitted)
- Commissioning, flame check and flow-rate test
- Issuing the gas certificate (required under NZS 5261)
- Registering the manufacturer warranty on your behalf
A straight-swap replacement of an existing Rinnai Infinity or Rheem Integrity is typically done in 2–3 hours. A conversion from a cylinder to continuous flow is a full day — around 6 to 8 hours — because we also remove the cylinder and re-route the water lines.
Considering Other Options?
Continuous flow is ideal for most Auckland homes with gas — but it's not the only option:
- Gas storage — Rheem Stellar 130L and 160L, indoor replacement for old Vulcan Freeloaders. Keeps hot water through power cuts.
- Integrated heat pump — the most efficient option, up to 75% cheaper to run than electric. Ideal if you're thinking of going off gas.
- Electric cylinder — simplest and cheapest upfront, and the usual path if you're disconnecting the gas line.
For the full continuous flow range and pricing, visit wgw.co.nz/hot-water/continuous-flow
Frequently Asked Questions
How much does a gas continuous flow hot water system cost in Auckland?
A Rinnai Infinity A26 is $3,599 incl GST fully installed. A Rheem Integrity 27 is also $3,599 installed. Supply only is $1,299. Prices include supply, installation, removal of your old unit, gas and water connection, commissioning and the gas certificate. Straight swap of an existing Rinnai Infinity is quoted separately — see the straight swap page.
Rinnai A26 or Rheem Integrity 27 — which should I pick?
The Rinnai A26 delivers 26 L/min at 25°C rise with a 44.5 kW output and is the best-selling continuous flow unit in New Zealand with the strongest parts network and a 10-year heat exchanger warranty. The Rheem Integrity 27 is a comparable unit at the same price. Both use electronic ignition and are available in natural gas and LPG. If you already have a Rinnai Infinity, the A26 is a straight swap with no rework.
Do continuous flow units use a pilot light?
No. Modern gas continuous flow units like the Rinnai A26 and Rheem Integrity 27 use electronic ignition — the burner only fires when you turn on a hot tap. No standing pilot, no wasted gas, no relighting if the flame blows out.
Can I just swap my old Rinnai Infinity for a new A26?
Yes — if you have an existing 20, 24, 26 or 32 series Rinnai Infinity mounted outdoors, we can do a straight like-for-like swap to a new Rinnai A26 in around 2 to 3 hours. Same bracket, same gas and water connections, same flue. See our Rinnai straight swap page for the full process and price.
Will one continuous flow unit run my whole house?
A single Rinnai A26 or Rheem Integrity 27 delivers 27 litres per minute at 25°C rise — enough for three simultaneous showers or two showers plus a kitchen tap. Larger homes with 4+ bathrooms may need a twin install or a 32 series unit, which we can quote on site.
Does continuous flow need mains water pressure?
Yes — continuous flow units require mains pressure water to operate correctly. If your home is on low pressure (from an old copper cylinder), we either do the mains upgrade as part of the install or recommend staying on a cylinder-based system.
How long does a continuous flow installation take?
A straight swap (replacing an existing Rinnai Infinity or Rheem Integrity with the same type) takes 2 to 3 hours. A conversion from cylinder to continuous flow takes a full day — around 6 to 8 hours — because we also remove the cylinder and re-route water lines.
Do I need a gas certificate?
Yes. Every continuous flow installation must be carried out by a licensed gasfitter and comes with a gas certificate issued under NZS 5261. Water & Gas Worx is registered with the Plumbers, Gasfitters and Drainlayers Board (PGDB) and every job includes the certificate.
