Roof space and the case for ducting
A ducted system puts one indoor unit in the ceiling and sends warm air to vents in each room. It needs room to run the ducts, and a single-level brick-and-tile or weatherboard home with an open roof space is close to ideal. In a two-level house, or one with a low-pitched roof, the job gets harder and the price climbs.
Ducting costs several times more than one high-wall unit, but it heats bedrooms, hallways and living areas together, with no units on the walls. If you only use two or three rooms in winter, separate high-wall units may suit you better. Our guide to ducted vs high-wall heat pumps compares the two.
Ask whether the ducted system can be zoned, so you can heat the living areas by day and the bedrooms at night. Zoning adds to the price, but it lets you heat only the part of the house you are using.
Older wiring can add to a Hamilton bill
A heat pump needs its own circuit. In a house built decades ago, the switchboard may have no spare space, or may still use old fuses rather than modern breakers. The electrician will need to sort that out first, and the cost is extra to the install.
Ask the installer to look at the switchboard during the quote visit, not on the day of the job. A written price for any board work means you can compare quotes fairly, since one firm may have priced it in while another left it out.
Homes with a ducted system or several wall units put more load on the supply. In that case the electrician may also check whether the main cable into the house is big enough, which is another reason to have the board looked at early.
Work out the size before anyone quotes
Installers in New Zealand often size a room at 120 watts per square metre if it is well insulated, 140 if insulation is average and 160 if it is poor, for a 2.4 m ceiling. Take a 40 square metre open-plan living area with poor insulation: that is about 6.4 kW, so you would look at a 7 kW unit. High ceilings and large windows push it up again, so get the installer to confirm.
Knowing the rough size before the visit helps you spot a quote that is far off. Our guide on what size heat pump you need has a fuller method.
Write the room sizes down before the visit.
What Hamilton's 53 installers offer
Of the 53 installers we track in Hamilton, 21 fit ducted systems, about two in five. Multi-split work, where one outdoor unit runs several indoor units, is far less common, with only 6 offering it. If that is the setup you want, you will have fewer firms to compare, so start asking early.
After the install, 32 of the city's installers offer servicing and 14 take on repairs. Ask how often the maker recommends a service and whether the warranty depends on it.
25 offer a free quote and 6 offer finance. Just 2 mention Warmer Kiwi Homes, the national EECA programme whose grants can cover part of the cost of a heat pump for eligible owners. EECA records each grant against the household's Community Services Card or SuperGold Combo card and the deprivation level of the area, so see whether you qualify on EECA's website. Our grants guide explains more, and our cost guide covers what a standard install includes.
Compare every installer on the Hamilton page, or read 10 Best Heat Pump Installers in Hamilton.