HVACopediaAll brands · General troubleshooting
One radiator cold
What is going on
Possible causes and checks for: one radiator cold.
Likely causes
- Radiator valve closed/failed (thermostat or valve), radiator air-bound (air vent failed), radiator full of condensate (steam trap failed). Tap with rubber mallet to confirm
- Cool, depressurize, replace
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Source: General HVAC service practice — verify per model. Written in our own words; check the manual for your exact model.
For licensed technicians. Gas, electrical and refrigerant work must be done by a qualified, licensed person. Shut off power and gas before servicing, never bypass a safety control, and follow the manufacturer’s manual for the exact model; it and local codes always take priority. HVACopedia is not affiliated with any manufacturer; brand and model names only identify the equipment.