Thames: what's different here
On the Firth
BRANZ's summary of NZS 3604 puts land within 500 m of the coast, or 100 m of a tidal estuary or sheltered inlet, in exposure zone D: a high risk of wind-blown sea spray.
A gold-rush town
Thames was built during the gold rush that followed the first major find on 10 August 1867. Its population was estimated at 15,000 in 1870 and had fallen to 4563 by 1881.
Hardly any new houses
Between 7 and 20 new dwellings a year were consented in the years to March 2019 through to March 2026, so most homes in town are established ones.
Floods on record
NIWA lists April 1981, when Paeroa and Thames were badly inundated and over 2000 people evacuated, and February 1985, when heavy rain brought a civil defence emergency to the Thames area.
Wood is still common
In 2023, 34.1% of Thames homes used a wood burner as a main heater, against 28.2% nationally, and 3.5% a portable gas heater, against 2.5%.
Mild nights
Wikipedia's table of NIWA's 1991 to 2020 normals gives a July mean daily minimum of 6.5 degrees and a February mean daily maximum of 24.9.
What Thames homes usually need
Corrosion protection, in writing. BRANZ says coastal installs need extra anti-corrosive coatings on the outdoor unit. Rinnai NZ and MHIAA make the owner responsible for added protection in sea air, and Black Diamond Technologies says Mitsubishi Electric units in coastal settings must be assessed first. Ask which rule applies to the unit you're quoted.
A heat pump sized for an older house. BRANZ says heat pumps don't replace good insulation, and Mitsubishi Electric NZ says the faster a home loses heat, the bigger the heat pump has to be. Check the ceiling and underfloor first.
An outdoor unit off the ground. With floods in the town's record, ask about a wall bracket or raised stand. BRANZ wants at least 100 mm of ground clearance in any case.
Regular servicing. Mitsubishi Electric NZ says coastal systems may need servicing more often than the yearly minimum, because salt speeds up corrosion. See heat pump servicing.
Tell us about the house when it suits you. If no installer near Thames takes it within 48 hours, it may be shown to heat pump installers in the rest of Waikato.
What we'd do
If we lived in Thames
We'd ask two questions before choosing a model: how far will the outdoor unit be from the water, and how high off the ground will it sit? Then we'd pick a unit whose sea-air warranty conditions we understood, and book servicing more often than an inland home would need.