What makes Sunbury different
Higher and further out
Sunbury is in the City of Hume, 38 km north-west of the CBD, at an elevation of about 309 m.
Cold nights nearby
At Melbourne Airport, July nights average 5.8 degrees (1991 to 2020), the coldest July night averages 0.9, and the record low is minus 2.8. There's no long-run Bureau table for Sunbury itself in our facts, so treat those as a guide.
New estates round the edge
Numerous new housing estates ring the established township. 88.5% of Sunbury's 14,118 occupied homes were separate houses in 2021.
Owners paying off homes
46.8% of homes were owned with a mortgage, 30.8% owned outright and 20.4% rented.
Sizing for a Sunbury winter
Mitsubishi Electric says a professional heat load calculation should account for climate, orientation, insulation, windows and doors, construction and ceiling height. In Sunbury, climate is the factor to press on. Rinnai says an undersized system often heats poorly and wears out sooner, so ask any installer to show you the heating figure they worked to, not just the cooling one.
If your heating is gas ducted, keep it serviced at least every two years by a gasfitter. Before a replacement, compare it with ducted reverse cycle on our Melbourne ducted heating page.
What's normal on a frosty morning
A reverse cycle unit heating on a cold, damp morning will sometimes stop. Mitsubishi Electric says frost forms on the outdoor unit when it's cold and humid, and the unit stops for up to 10 minutes to defrost. The white "smoke" you may see is vapour from that defrost. Water dripping from the outdoor unit while it heats is normal too.
What isn't normal is a unit that stops heating for long stretches, trips the breaker, or makes new grinding or rattling noises. That's a job for a repairer: see air conditioning repairs in Melbourne.
Building in one of the new estates?
From 1 January 2027, every new Victorian home is built all electric, and connecting reticulated gas to a new house is prohibited. A house started in a Sunbury estate from then on will have electric heating, so ask the builder exactly what's included: the system type, the brand, its heating capacity and the zones.
What we'd do
What we'd do in Sunbury
Size everything for the coldest weeks. With a gas ducted heater that works, we'd service it and add a split where summer bites. Replacing it, we'd have ducted reverse cycle quoted with the heating capacity and zones spelled out, and we'd book it for autumn, well before the first frost.
Post the job with your 3429 postcode. Local installers who do that work, licences checked, can see it, and only the one who takes it gets your details. If nobody up around Sunbury takes it within 48 hours, installers elsewhere in Victoria may see it too.
