Install a condensate pump for a furnace or AC coil (with overflow safety switch)
A condensate pump collects water from the evaporator coil and, on high-efficiency furnaces, the furnace drain, then lifts it to an approved drain. It must sit level with its inlet below every drain that feeds it, and its overflow safety switch should be wired so a full reservoir shuts off cooling (or the system) or sounds an alarm. Discharge routing and check-valve use follow the pump's instructions.
Cross-checked ~90 min moderateBrands: All
Before you start
- Turn off power to the furnace/air handler and unplug the pump before working.
- The safety switch is wired into the 24 V control circuit: keep the low-voltage and line-voltage wiring separate.
- Hardwiring a pump to line voltage or adding an outlet is for a qualified electrician where required.
- A safety switch on the R wire stops heat too; in cold climates consider wiring it to stop cooling only, or use an alarm, so pipes cannot freeze.
Diagnostic steps
Unlock all 10 steps with expected values
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