Hydronic Heating & Cooling Specialists
Hot Water Systems

Electric Hot Water

Storage electric is the simplest hot water system — but it's also the most expensive to run. We'll spec one if it suits, or steer you toward heat pump or solar instead.

Electric storage hot water system

Electric storage is the cheapest to install and the most expensive to run — by a clear margin. A 250L electric storage system uses 4,500–5,500 kWh/year (~$1,500/yr at 30c/kWh).

It still has its place: holiday homes, very small households, or where there's no gas and no roof for solar.

Key benefits

  • Lowest install cost
  • Simple, reliable technology
  • Off-peak rates available
  • 10-year tank warranty (Rheem/Rinnai)
  • Compatible with solar PV battery
  • Element replacement is straightforward
FAQs

Common questions

Why is electric hot water so expensive to run?

Direct electric resistance heating has a COP of 1.0 — every unit of electricity becomes one unit of heat. Compare to a heat pump (COP 3.5–4.5) which produces 3–4× the heat for the same electricity. A typical 250L electric storage unit costs $1,300–$1,700/year vs $400–$500 for a heat pump.

When does electric storage still make sense?

Holiday homes (used rarely, low total energy), very small households (1–2 people, low hot water use), or homes with no gas access AND no roof space for solar/heat pump. Otherwise, almost always specify a heat pump instead.

Can I use off-peak rates?

Yes — electric storage is the only system that pairs cleanly with off-peak (controlled load) tariffs. Off-peak typically saves 30–40% on running costs vs anytime electric tariffs. Check with your electricity retailer for available off-peak plans.