Signs the ducts are the problem, not the heater
The rooms furthest from the unit never get warm while the closest room cooks. Airflow at the far outlets feels weak even on high fan. The heater runs constantly and still doesn't reach the set temperature.
Whistling, roaring or rattling in the roof space. Dust blowing out of the vents. A heating bill that climbed without you changing anything. Any of those points at ducting, not the appliance.
What we find in older roof spaces
Crushed runs where someone has walked or stored boxes on them. Disconnected ducts that have popped off a collar and are now heating the roof space. Rodent damage — extremely common in Lara, Hamlyn Heights and older Bellarine homes.
Uninsulated or R0.6 ducting from the 1990s, which loses a large share of its heat before it reaches the room. Undersized branches installed by a builder to save metres of duct.
Cost, in real numbers
A photographed roof-space inspection with airflow readings at each outlet starts at $150, credited against the work if you go ahead. A single crushed or disconnected run is typically $180–$450 including the visit.
Full replacement with correctly sized R1.0–R1.5 insulated ducting is quoted on site because it depends on run lengths, roof access and outlet count. Vent and register replacement is usually a small add-on while we're there. Adding zoning starts around $950.
When it's worth it
Always assess the ducts before buying a new heater. Spending thousands on a high-efficiency unit and connecting it to failing ducting is the most expensive mistake we see.
If your unit is sound and only the far rooms are cold, duct repair is dramatically cheaper than a changeover and usually fixes the complaint completely.
Anything involving gas, refrigerant or the inside of the unit is licensed work. If you smell gas, shut the gas off at the meter and call the gas emergency line first.
We photograph every run so you can see exactly what you're paying to fix — no "trust me, it's bad up there".
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