Stop using it first if
Mitsubishi Electric says to stop the unit and turn off the breaker if there's a burning smell, and to stop using it and have it checked if the breaker trips often or water leaks from the indoor unit. Don't open it or touch the wiring.
Checks worth doing before the quiz
Power and settings
Check the breaker is on, and that a timer or sleep setting isn't switching it off. Mitsubishi Electric says a unit won't restart for about 3 minutes after it's switched back on, so give it time.
Filters
Daikin says blocked filters can cut a system's efficiency significantly. Clean them the way your manual says.
The outdoor unit
Daikin says to keep it clear of leaves and debris. Look, don't poke, and don't stand on it.
How the quiz leans, and why
A first fault in a system that's otherwise been reliable is usually worth a repair visit, and a good technician will say so if it isn't worth fixing.
Age changes the sums. In Solar Victoria's buyers guide, a system past 15 years typically uses over three times the energy a modern reverse cycle unit needs. If yours is that old and the fault keeps returning, a replacement quote next to the repair quote is worth the wait.
If it's not cooling or heating, Mitsubishi Electric says a refrigerant leak is one possibility. The ARC says topping up a system before it's been tested and every leak repaired is illegal, whoever does it, so a fix that's only a top-up isn't a fix.
Signs a repair quote isn't right
- A regas offered without anyone looking for the leak.
- No Refrigerant Trading Authorisation number on the quote.
- Pressure to sign for a new system on the spot. A deal struck at your kitchen table can carry a 10 business day cooling-off period.
What we'd do
If it were ours
We'd do the safe checks first, because a tripped breaker or a clogged filter takes minutes to sort. If it's still faulty, we'd book a repair specialist for a first-time fault. If the system is over 15 years old and the same problem keeps coming back, we'd get both quotes before spending anything on it.