GeneralTroubleshooting2026-02-26
Condensation on Windows and Your Heating
Excess indoor condensation can signal ventilation or combustion issues worth checking.
Heavy window condensation is usually humidity, but combustion problems can contribute.
Common causes
Most condensation is indoor humidity and poor ventilation; however, a yellow flame or soot near the boiler can indicate incomplete combustion.
What to do
Improve ventilation and humidity control; if you see soot or a yellow flame, have the boiler's combustion checked promptly.
Key takeaways
- Usually humidity and ventilation
- Soot/yellow flame = combustion issue
- Improve ventilation
- Get combustion checked if in doubt
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