Sta-Rite SR333 AFS Code

[CBourg3]

I have a Sta-Rite SR333 Max E-Therm heater with a AFS code. Air Flow switch has been replaced and still have error. If I blow in to the tubing going to the AFS, the error clears.
I took the lid to access the coils to validating no blockage any where.
Blower spends freely and sounds normal. Is it possible that motor is starting to fail?

Thoughts

 

[ajw22]

Welcome to TFP.

@ps0303 @Pool Clown @swamprat69 thoughts?

 

[Pool Clown]

Can you post a pic of your new air switch?

 

[swamprat69]

Never blow into the tubing towards the pressure switch as you can damage the diaphragm in the pressure switch. Some, but not all pressure switches have a make/break point on their label listed in + or - inches WC (water column). You can disconnect the tubing at the pressure switch and use a manometer to see if the actual pressure is greater than the plus rating or less than the negative rating to tell if the pressure switch should be closing. Some pressure switches have 2 pieces of tubing attached and are measuring differential pressure and would benefit from a digital manometer that has 2 access points to attach the tubing. You would disconnect the wires to the pressure switch and attach a multi-meter set to ohms to observe the switch contacts opening and closing. If the motor is slowing down due to bearing wear you would expect it to draw more amperage than is listed as FLA on the motor nameplate measured with an ammeter. It is also possible that the blower is moving less air if the cups of the vanes on the blower wheel/squirrel cage are filled with dirt or are starting to rust away. In this case the amperage reading of the motor would read less than the FLA because of decreased load on the motor