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Starts but locks out — no oil at nozzle
What is going on
Possible causes and checks for: starts but locks out — no oil at nozzle.
Likely causes
- Clogged nozzle
- Pressure too low
- Fuel unit dead
- Loose motor coupling
- Air leak in line
- Shutoff closed
- Strainers clogged (filter, pump screen, nozzle)
- Pump regulator stuck open
- Tank vent closed
- Empty tank
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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.