Furnace: Starts but locks out — no oil at nozzle
Starts but locks out — no oil at nozzle on a furnace: Possible causes and checks for: starts but locks out — no oil at nozzle.
Common causes of starts but locks out — no oil at nozzle
- 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
If the unit shows an error code, look it up: AirQuest Furnace codes Carrier Furnace codes Daikin Furnace codes Goodman Furnace codes ICP Furnace codes KeepRite Furnace codes Lennox Furnace codes Midea Furnace codes Rheem Furnace codes Trane Furnace codes York Furnace codes
Source: General HVAC service practice — verify per model. Written in our own words as a summary; always check the original manual.
General guidance for qualified technicians. The manufacturer's installation and service manual and local codes always take priority. Aurora Star Tech is not affiliated with, endorsed by or sponsored by any equipment manufacturer; brand and model names are used only to identify equipment and belong to their owners.