Wellington conditions that affect your cylinder
Ripple control at peak times
Wellington Electricity, the local lines company, can shed load by sending a ripple signal that cuts power to some home cylinders. Water that's already hot still comes out of the tap and usually stays warm for several hours. Households on 'controlled' electricity rates get a discount for allowing it.
Strapped for the next big shake
WREMO points out that the region's water network crosses fault lines in several places, and that your cylinder and toilet cistern are valuable water stores afterwards. Its home safety checklist includes securing the cylinder and any header tank. Restraints help; nothing makes a cylinder earthquake proof.
The toby is your off switch
Tiaki Wai's toby is the valve that cuts water to the whole house, usually found at the boundary under a black, blue or metal lid. A cylinder that springs a leak is one of the reasons it gives for knowing where yours is.
Gas is common here
At the 2023 Census, 17.5% of Wellington City homes listed a fixed gas heater among their main heating, against 9.5% nationally, and Powerco's gas pipes run under the city.
Cylinder gone cold? Check in this order
The switch at the switchboard
Make sure the cylinder's switch is on and nothing has tripped.
The time of day
On a controlled rate at peak time, heating may be paused for a while. Your retailer can tell you your plan.
Still cold the next morning
Then the cylinder itself needs testing by a hot water specialist, or an authorised gasfitter if it runs on gas.
Water underneath or dripping
Turn off the cylinder's power or gas and close the toby. Then book a specialist to find out whether it's a valve, a fitting or the cylinder.
Heat pump, gas or electric in a Wellington climate
A heat pump water heater pulls warmth out of the outside air, so it needs outdoor space. NIWA records no air frosts in an average year at Kelburn, though sheltered valley spots such as Wallaceville get far more, and frost varies a lot across the hills. Rheem fits its heat pump models with an electric back-up element for very cold weather.
Going gas? An authorised gasfitter connects the heater, and once it's connected you're owed a Gas Safety Certificate. Rheem notes a continuous flow unit generally needs a larger pipe from the gas meter than a storage heater, so ask early whether yours will do. Our califonts page compares the options.
Wood burners are a main heating type in 11.9% of Wellington City homes, under half the national 28.2%. That's space heating, not hot water. If your burner does heat water through a wetback, a new cylinder escapes consent only if it's a comparable open-vented one in the same spot on the same pipework.
The rules, wherever you live
Replacing or repairing a cylinder is plumbing work, and the person doing it must be authorised, usually by holding a current PGDB practising licence.
Some cylinder replacements are exempt from building consent under the Building Act, but only under particular conditions, only with an authorised person doing the work, and never exempt from the Building Code. Our consent guide takes the clauses one at a time, and the national cylinder page covers repair versus replacement.
Questions for a Wellington hot water specialist
- Is our cylinder, and the header tank if we have one, properly restrained?
- Could load control explain our lukewarm evenings?
- Would a heat pump unit work where our section sits?
- If we change to gas, will the pipe from the meter need upsizing?
What we would do
Rule out the switchboard and your power plan first. A puddle under the cylinder can't wait, though. Turn the power or gas off, shut the toby, and get it looked at that week. And whatever cylinder you end up with, have the installer check its seismic restraints before they leave, because in Wellington that cylinder may be your water supply after a big quake. When you're ready, we'll pass the job to a hot water specialist who works around Wellington.