24/7 Emergency0466 442 293
From Leaks to Blockages — We've Got You Coveredshellharbourplumbing@gmail.com
Buyer's Guide

Rheem vs Rinnai vs Dux: Which Hot Water Brand Lasts Longest in NSW?

After 15 years of warranty call-outs across the Illawarra, here's what we actually see fail first — and which brand we'd put in our own house.

26 February 2025 7 min read

Every fortnight someone in Shellharbour or Wollongong asks us which hot water brand is best. The honest answer depends on fuel type. We install roughly equal numbers of Rheem, Rinnai and Dux units across the Illawarra, and warranty failure patterns by brand are very consistent.

Electric storage: Rheem and Dux lead

For 250L–315L electric storage tanks, Rheem (Stellar / Optima) and Dux (Proflo) consistently outlast the budget brands. We see element and thermostat failures at 6–8 years on both — easy repair — and body / tank failures around 11–14 years. The vitreous enamel lining and sacrificial anode quality is the actual difference. Replace the anode at year 5 and you'll often add 4–5 years of tank life.

Gas continuous flow: Rinnai by a nose

Rinnai Infinity remains the workhorse of NSW continuous-flow gas — the heat exchanger is robust, ignition modules are cheap and stocked everywhere, and parts are available for 15+ year-old units. Rheem Metro is also very strong; Bosch has a smaller parts network in the Illawarra so we tend to avoid it for new installs unless requested.

Heat pumps: a different question

Reclaim, iStore and Sanden lead the premium end (CO2 refrigerant, longer warranty). Rheem Ambiheat is the entry-level heat pump that's eligible for the NSW ESS rebate. We've now got Reclaim units in the field at 6+ years with zero call-outs.

What we'd put in our own house (2025)

  • Family of 4–5, gas connected: Rinnai Infinity 26
  • Family of 4, no gas, sunny block: Reclaim heat pump
  • Investment property, electric only: Rheem Stellar 315L
  • Single / couple, gas connected: Rinnai Infinity 20

Whatever you choose, the install matters as much as the brand — tempering valve, pressure-limiting valve, correct isolation and a Certificate of Compliance are all non-negotiable. Brand-loyalty isn't a substitute for a clean install.

Got a plumbing question?

Send it over and a licensed plumber will get back to you — no obligation, no upsell.

Request a callback

Tell us what's going on — we usually call back within 15 minutes during business hours.

Or call us directly on 0466 442 293.

Call 0466 442 293 Email