The usual suspects
A clogged condensate drain or trap
Condensing furnaces produce gallons of slightly acidic water; the internal trap clogs with sludge and it all finds the floor.
A failed condensate pump
No floor drain nearby means a little pump lifts the water out. When it dies (or its float sticks), water pools fast.
Summer AC condensate, not furnace
The AC coil sits ON the furnace — in cooling season, "furnace leaks" are usually the coil’s drain overflowing through it.
A cracked heat exchanger drain path or humidifier leak
Whole-home humidifiers and secondary drain pans fail quietly. Less common, worth ruling out.
Water plus furnace electronics is a bad mix.
Drain lines, traps and condensate pumps are on-truck fixes — usually one visit, price approved first.
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Worth trying first (5 minutes, free)
- 1
Kill the furnace switch and mop up — keep water away from the base and board.
- 2
Look for the clog: follow the plastic tubing; if a condensate pump has a full reservoir, its outlet or float is stuck.
- 3
Running AC? Check the coil drain above the furnace — see our AC leaking-water guide.
- 4
Note when it drips: only while running vs constantly — tell us when you book.
Still not working? Then it’s a technician job — and the sooner it’s booked, the sooner the house is comfortable again. Book the visit →
Stop and book a pro if…
- Water reaching the control board or blower — keep it off.
- Rusty streaks and long-term dampness — corrosion is cumulative.
- A humidifier line spraying — close its small saddle valve if you can see one.
- Leak returns days after clearing — slope, trap or pump needs a real fix.
Why homeowners hand it to us
- You approve the price first. Upfront quote before a single screw turns.
- Same-day service. Book in a minute, hear from a tech within 1 business hour.
- 500+ jobs done by 4.9★ rated, professional technicians.
- Fixed right, guaranteed. If it’s not right, we make it right.
Quick answers
My furnace is 20 years old and never leaked. Why now?
Older non-condensing furnaces shouldn’t produce water — on those, "furnace water" is almost always the AC coil above it or a humidifier. Newer high-efficiency units make water every hour they run; theirs is a drain problem.
Is the water harmful?
It’s mildly acidic condensate — hard on concrete, flooring and metal over time, and a mold invitation. Not a health emergency, but not a wait-a-month problem either.
What does the fix usually involve?
Clearing or rebuilding the trap and drain line, or swapping the condensate pump — on-truck parts, one visit, upfront price.
Done guessing?
Every day it drips costs flooring and risks the control board. Book the fix today.
Book My Same-Day Visit60 seconds online · or call (206) 486-6373
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