SECTION FOUR – Routine Maintenance and Professional Servicing
LLLLooooccccaaaattttiiiioooonnnn
The Air Flow Switch (AFS) is fastened to the Control
Box.
FFFFuuuunnnnccccttttiiiioooonnnn
The Air Flow Switch senses the pressure differential
across the air orifice to prevent the burner from firing if
there is insufficient air flow. The AFS is factory-set and
is nonadjustable.
SSSSeeeerrrrvvvviiiicccciiiinnnngggg PPPPrrrroooocccceeeedddduuuurrrreeee
To replace the AFS:
1. Turn off the pump and all electrical power to the
heater.
2. Disconnect the plastic tubing from the AFS fittings.
3. Disconnect the wires from the AFS.
4. Remove the screws fastening the AFS to the Control
Box.
5. To Replace the AFS, reverse Steps 1 through 4
above.
4-9
Air Flow Switch
2657 1096
PRESS
TAB
VENT
PILOT
OFF
O
N
ON
Air Flow Switch (AFS)
P/N 42001-0061S
