Clear and rinse the outdoor unit
Leaves, snow and plants blocking the coil cut efficiency.
Who: You can do it yourself, or have an HVAC technician do it. Clearing and an outside rinse: you. Inside the cabinet: a pro. Trane’s coil page and Lennox’s warranty point to a professional; read your warranty.
How often: Check monthly; clean yearly before cooling season. For: the air conditioner, heat pump.
Safety first
- Power off at the outdoor disconnect or the breaker.
- Don’t open the cabinet.
- No pressure washer or jet setting.
- No wire brush, bleach, ammonia or household cleaner.
- Don’t leave a heat pump’s power off for hours: after a long outage Lennox says run Emergency Heat and wait 6 hours, and Trane says power off more than 3 hours means waiting 3 hours after it returns. A one-hour job stays under both.
What you need
- A garden hose with a gentle nozzle.
- A shop vacuum with a soft brush.
Time: Let it dry 30-60 minutes before the power goes back on.
How to do it
- Turn the power off.
- Clear leaves, grass and twigs from the top, sides and base; make sure the base pan drains and nothing has settled in it.
- Vacuum the fins with the soft brush, straight up and down, never sideways.
- Rinse from the top down with a gentle stream, on all four sides including the back; keep water off the electrical parts.
- Let it dry 30-60 minutes, then turn the power back on.
- Keep it clear: Trane says 2 feet on all sides and 4 feet above; Bryant’s manual says 12 inches minimum; your manual rules. No cover and nothing set on it. Keep sprinklers off it, mow so clippings blow away from it, and keep dogs away. Near the coast, wash it about every 3 months.
- Monthly: check that the indoor condensate drain line is clear.
- Winter, heat pump: clear heavy snow off the top and sides, and keep snow below the louvers. Condensing furnace: keep the intake and exhaust PVC pipes clear of drifts. Never chip ice or pour hot water on the unit.
Normal
- Heat pump in winter: frost on the coil below about 45°F, cleared by a defrost of 5-15 minutes at intervals. During a defrost the fan stops, steam or fog rises, there’s a whoosh at the start and end, the thermostat may show AUX heat, and the air is briefly cooler.
- Thin frost, under 1/4 inch.
Needs attention
- Ice thicker than 1/4 inch, a solid coating, or ice that a defrost doesn’t clear.
- Defrosts that get longer and longer, or never stop.
- Ice on the fan.
- The unit running without stopping.
- Ice that comes back soon after thawing.
- Water from a leaky gutter freezing on it.
- Bent fins.
Call an HVAC technician if
- Ice first: turn it off at the thermostat, clear snow and debris, check the filter, that the thermostat is on Heat, and the breaker. Above freezing it thaws in 2-4 hours; if it refreezes or won’t restart, call.
- Bent fins, or an electrical burning smell.
Keep track of it
Add your home to My homes: each piece of equipment gets this on its own schedule, with “Mark done” and reminders you can turn on.
Sources
- Bryant
- Carrier
- Trane
- Trane
- Carrier
- Bryant (owner’s manual)
- Rheem (heat pump guide)
- Lennox (heat pump user guide)
- Trane (owner’s guide)
- Lennox
- Trane
- Lennox
- Lennox (warranty)
Your owner’s manual comes first: where it says something different for your model, follow it.
Still stuck?
Email us at hello@tradewrench.com. Tell us which page you were on and what you were trying to do.