How much does it cost to replace a hot water cylinder in NZ?
Real numbers from the New Zealand market, split into what the cylinder costs and what the installation costs.
Last reviewed 2026-09-02
Almost every page that answers this question in New Zealand ends with "contact us for a fixed price". Here are the actual numbers instead.
Two things make up the total, and it helps to look at them separately, because you can control one of them.
1. The cylinder itself
Supply-only prices in the New Zealand market, as at September 2026:
| Type | Typical supply price |
|---|---|
| Low pressure cylinder, 135L | $1,600 – $1,800 |
| Mains pressure electric, 180–250L | $1,200 – $2,000 |
| Continuous flow gas unit | $1,250 – $1,400 |
| Heat pump cylinder, 200–330L | $4,000 – $5,000 |
This is the part you can shop for. It is a physical product with a model number, and the price varies more than people expect depending on who you buy it from.
2. The installation
Installation is quoted per site, but the market gives a reasonable indication. A supply-only listing and an installed listing for the same low pressure 135L cylinder in Auckland were advertised at $1,693 and $2,650 respectively — an installation component of roughly $950 for a straightforward like-for-like swap.
That figure goes up when the job is not like-for-like:
- Converting low pressure to mains pressure — the pipework and valves change, and the header tank comes out.
- Electric to heat pump — the unit goes outside, which means new pipe runs, and the electrical supply usually needs work.
- Awkward access — a cylinder in a roof space or a tight cupboard takes longer to remove than one in a garage.
What the fully installed prices look like
For heat pump systems, advertised installed prices in Auckland at the time of writing sit between roughly $6,700 and $8,300 depending on brand and size, with occasional promotions below that. Those advertised figures generally include the electrical work, the valve set, seismic restraints, a set allowance of pipework, disposal of the old cylinder, and travel within a set radius.
When you compare quotes, compare what is included rather than the headline number. A cheaper price that excludes the electrician is not cheaper.
What is always in the job
Regardless of type, a compliant replacement includes a new valve set — tempering valve, pressure reducing valve and expansion control valve — plus seismic restraint straps. These are not optional extras. If a quote does not mention them, ask where they are.
The honest summary
- Cheapest route — like-for-like electric cylinder, straightforward access. You are looking at the cylinder price plus roughly a thousand dollars.
- Most expensive route — changing type, particularly to a heat pump, where both the plumbing and the electrical work change.
- Best long-run value — a heat pump, if you are staying in the house. It costs more on the day and about a third as much to run.
Prices move, and these are market observations rather than a quote. What we can tell you exactly is what the cylinder costs — every one we sell has its price on its page.