Keep a Bathroom Warm in Winter
Part of our Ventilation & Hot Water guides.
Heat the air
An exhaust fan with 1500 W heater warms the room after a shower while removing moisture.
Warm towels
A towel warmer on a timer has towels warm when you step out.
Warm seat
Smart bidet seats offer heated seats.
Hot water
Incoming water can drop near 40°F in northern winters, cutting tankless output. Size up; see tankless for one bathroom.
Why bathrooms get so cold
Bathrooms are often on exterior walls with windows and tile floors, and exhaust fans pull warm air out. Small rooms also lose heat quickly once the door opens.
Insulation and drafts
Check that the exhaust fan has a working backdraft damper; a stuck damper lets cold air in all winter. Seal gaps around windows and plumbing penetrations. Insulated window coverings help.
Warm floors
Electric radiant floor mats under tile are a popular remodel upgrade in cold regions. If you're not re-tiling, a thick bath mat and slippers make a big difference.
Frozen pipes
Bathrooms on exterior walls are prone to frozen pipes. Keep the vanity doors open during cold snaps, let faucets drip slightly, and insulate pipes in exterior walls when you can access them.
Frequently asked questions
Is a heater fan safe in a bathroom?
Models designed for bathrooms are; install on a circuit sized for the heater per local code.
Are heater exhaust fans expensive to run?
A 1500 W heater used for 15 minutes uses about 0.375 kWh, so short sessions are inexpensive.
Can I add heated floors without removing tile?
Generally no; radiant mats go under tile. Plan heated floors during a re-tile.
How do I stop the bathroom window from icing?
Better ventilation and running the fan after showers reduce condensation that freezes on windows.
What about cold toilet seats?
Electric bidet seats often include heated seats; it's one of their most appreciated features in cold homes.