Most brands leave you to work that out from a spec sheet. If you are seeing C467, you have your answer.
Three more things that stop a Samsung heating and are not faults
- Timer standby. A lit timer indicator with no operation usually just means a timer is armed and the unit is waiting for its scheduled start. Cancel the timer or wait for it.
- 3-minute standby. Samsung delays compressor restart by about three minutes after power-up or a restart, to protect the compressor. Repeatedly pressing buttons or cycling the breaker only restarts the clock - wait it out.
- Defrost. The indoor fan pauses and the outdoor unit may steam while it clears ice. Keep snow clear around the base, but do not chip ice off the coil.
Samsung publishes twelve of these status indicators - among the most of any brand we catalogue - so on a Samsung it is genuinely worth identifying what the display is telling you before assuming a fault.
If you have more than one indoor unit
C142 is a mixed-operation error: zones asking for heating and cooling at the same time. One outdoor unit cannot do both, so it stops or limits operation. Set every connected indoor unit to one shared mode - all Heat, all Cool, or all Off
- wait a few minutes, and it clears.
This is worth checking before anything physical. A single head left on Cool in an unused room is enough to stop the rest of the house heating.
Safe checks
- Read the display first - C467, timer standby, 3-minute standby or defrost all explain themselves.
- Mode and setpoint - HEAT, not AUTO or FAN, several degrees above room temperature.
- C142 mode conflict if you have multiple heads.
- Filters, then return and supply air paths.
- Outdoor unit clearance - snow, ice, leaves, with the power off.
- Know your model's floor - check its rated minimum outdoor temperature in the database. C467 is that limit being enforced.
When to stop and call a technician
Samsung's numbered C codes beyond the three above cover sensor, communication, inverter and compressor faults, and they are diagnosed with instruments rather than checked from a list. Look yours up in the Samsung error-code library so you can tell the technician what the unit is reporting.
Call as well if the unit cools normally but never heats - that points at the reversing valve - or if the outdoor coil ices over and never clears through a defrost cycle.
If it is turning into a replacement decision, the installation cost estimator will size it.