What's usually wrong (and what it means).
- Not heating / blowing cool air: often low refrigerant from a leak, a failed reversing valve, or sensor issues. In cold snaps, check it isn't just defrost mode.
- Ice buildup on the outdoor unit: some frost is normal; a solid ice block means a defrost fault or airflow problem — shut it off and call before the fan damages itself.
- Short-cycling (constant on/off): oversized equipment, low charge, or control faults. Chronically short-cycling systems die young — worth fixing properly.
- Grinding, buzzing or rattling: fan motors, mounts, or compressor issues. Buzzing at the outdoor unit can be electrical — don't ignore it.
- Indoor head dripping water: blocked condensate drain — quick fix, but it'll damage drywall if left.
The rebate secret on dead systems
If your system (or furnace) is beyond saving: emergency replacement of a broken heating system can still qualify for BC's income-tested rebates — up to $16,000 on qualifying conversions. The any-income program doesn't allow this, but the income-tested one does. It's one of the most valuable things to know on the worst day of your heating system's life. Current rebate details →