Troubleshooting guide
Heat pump leaking water? Here is what is happening and what to do.
Water leaking from an indoor mini-split unit is almost always a clogged condensate drain line. The drain pan fills, then overflows. You can sometimes clear it with a wet/dry vac at the outdoor end of the drain line. If that doesn't work, or you see water on a regular basis, the line needs to be professionally cleared and the pan cleaned.
Likely causes, ranked by probability
- 1
Clogged condensate drain line
Algae or biofilm blocking the drain.
Likelihood 70%
- 2
Cracked or misaligned drain pan
Less common but possible in older units.
Likelihood 15%
- 3
Frozen evaporator coil thawing
Coil iced up, then melted and overwhelmed the pan.
Likelihood 15%
What you can try first
- · Use a wet/dry vac at the outdoor end of the drain line for 1-2 minutes
- · Place a towel under the unit while you assess
When to call us: Vac attempt fails or leaking persists.
When a cleaning helps, and when to call a repair pro
A good portion of “something is off” symptoms (musty smell, weak airflow, water dripping from the indoor unit, surface mold) trace back to a dirty blower wheel, clogged drain, or biofilm on the coil. A full disassembly cleaning solves those. If we get on site and find an electrical or mechanical fault (a failing capacitor, a stuck reversing valve, refrigerant issues), we will tell you and recommend a heat pump repair contractor. We do not do repairs ourselves.
Frequently asked questions
Is heat pump leaking water dangerous?
Most causes of "heat pump leaking water" are not immediately dangerous, but ignoring them can damage the system over time. Vac attempt fails or leaking persists.
Can a cleaning fix this?
Sometimes. Biofilm, dirty coils, and clogged drain lines often resolve after a deep clean. Mechanical or electrical issues need a heat pump repair contractor instead.
Do you do repairs?
No. We focus on cleaning and twice-yearly maintenance. If your system needs a part replaced or an electrical fix, we will tell you what we see and recommend a repair contractor.
Try a cleaning first.
If the symptom traces back to a dirty unit, we can fix it. If it does not, we will tell you and point you to a repair pro.