What's different about cylinders in Christchurch
Winter-only ripple control
Orion sends ripple signals through its network to switch electric cylinders off when winter demand peaks. Those control periods can only fall between 1 May and 31 August, and its target is no more than 4 hours without heating in any 8. Night rate water heating runs all year.
Water from deep aquifers
The city's drinking water comes from deep aquifers. In the council's typical analysis, total hardness sits at 45 g/m³ as calcium carbonate, which counts as soft to slightly hard.
Gas means bottles
There's no piped natural gas in the South Island. A gas storage heater or califont in Christchurch runs on LPG, usually 45 kg bottles delivered to the house, and the gas side is work for an authorised gasfitter.
Pellet fires and burners
At the 2023 Census, 17.6% of Christchurch dwellings used a wood burner as a main heater and 2.9% a pellet fire, more than three times the national pellet share. Those are space heating figures, but if your fire has a wetback, it changes which cylinder can replace yours.
Before you blame the cylinder
- Is it winter, at a busy time of day? Orion's control periods only run from May to August, and usually end within a few hours.
- Ask your electricity retailer which plan you're on. Orion says plans with more, or uninterrupted, water heating exist, at a slightly higher price.
- Check the cylinder's switch and breaker at the switchboard.
- On LPG, check whether the regulator's arrow shows a bottle has run empty.
- Cold all day, in any season, or water underneath it: that points at the cylinder, a valve or a fitting.
Choosing a replacement here
A like-for-like electric cylinder is the simplest swap, and on Orion's network it can stay on whichever plan suits you. A heat pump water heater takes warmth from outdoor air and needs outdoor space, which matters in a city with frequent winter frosts; our Christchurch page on them covers that.
LPG suits homes that already have bottles. Rockgas lists heat pumps, air conditioning units and outdoor power outlets among the ignition sources a bottle must be kept clear of, so the position of a new gas heater, its flue and the bottles needs planning together.
With a wetback on a wood or pellet fire, the Building Act only exempts a replacement from consent if it's a comparable open-vented cylinder fixed in the same position on the same pipework (Schedule 1, clause 37). Anything else, ask the plumber which clause applies or whether consent is needed.
Who can do the work, and the paperwork
The plumbing must be done by someone authorised under the Plumbers, Gasfitters, and Drainlayers Act 2006, usually with a current PGDB practising licence. Repairing a water heater with comparable products is consent-exempt (clause 36), and replacing or repositioning one is exempt when the new heater includes, or is connected to, a controlled heat source (clause 38). Either way the work must meet the Building Code. Wiring is an electrician's job.
For an LPG heater, the gasfitter who connects it, or their supervisor, issues a Gas Safety Certificate once it's connected, and new installations also need a certificate of compliance. Our consent guide and the national cylinder page go into the detail.
Questions for a Christchurch hot water specialist
- Is this cylinder failing, or is it Orion's winter control?
- Does our fire have a wetback, and does that limit what we can fit?
- If we go to LPG, where can the bottles and the heater both go?
- Would a heat pump water heater cope with our frosts, and where would it sit?
What we would do
If the water is only lukewarm on winter evenings and fine by morning, talk to your retailer about your plan before paying anyone to test the cylinder. Water on the floor is different: switch the cylinder off, close the cold supply if you can do it safely, and book a specialist that week. And if your house has a wetback, say so when you describe the job, because it decides which replacements avoid a building consent.