Description

The Raypak 010355F is the blower pressure switch for the model 407A Low NOx pool heater. It is the genuine Raypak OEM part.

What it is doing

The switch is a safety interlock. It watches the pressure the combustion blower creates and closes only when air is genuinely moving. The control board waits for that signal before it lets the heater light, which is what prevents a burn without proper airflow.

How it fails

The usual symptom is a heater that will not fire even though the blower is clearly running. The switch has stopped closing, so the board never sees its proof of airflow and holds the ignition sequence.

While you are in there

Look at the sensing tube before you condemn the switch. A tube that is cracked, kinked, plugged with soot or holding condensate will keep the pressure signal from ever reaching a perfectly good switch, and it costs nothing to check.