Diagnostic 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.
Our diagnostic process
We arrive within a one-hour window, inspect the system end-to-end, read any active error codes, test temperatures and pressures, and identify the actual cause. You get a written quote before any repair work starts. The $129 diagnostic fee is applied to any repair you proceed with.
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 or raise repair cost. 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 require a diagnostic visit instead.
How much does diagnosis cost?
Our diagnostic visit is $129 flat, applied to any repair you proceed with. We will quote any repair before starting work.
Need a tech to take a look?
$129 flat diagnostic. Same-week scheduling across Vermont. Credited toward any repair.