Wiring Question: Replacing old 2 Speed with new VS Pump

After 18 years of mostly hassle free service, my old Pentair WhisperFlo (2HP 2 Speed) finally went to the great pool equipment scrapyard in the sky. So I decided to replace it with a new Pentair SuperFlo VS, and I have a few of questions in regards to wiring. The old system ran through an analog timer to cycle the filter in low speed mode and an "air switch" to activate the high speed and heater function.

Pool Information: 1000 Gallon - In ground hot tub

1) The old 2 speed motor had 4 wires attached to it: "L1" Black, "L2" Blue, "GND" Green and "A" Brown. I know L1, L2, and GND are my 220 supply and am clear on their connection. However, what about the "A"? I assume this was the connection for the low-speed function and is eliminated with the new VS motor.

2) Can the "air switch" be removed? I assume I will now be using the control panel on the pump to select a high speed setting and that this higher flow rate is what activates the heater.

3) Finally, since the new VS motor has programming and speed control I assume that the analog timer can be completely removed.


Well-known member
Mar 10, 2017
House Springs
Is it a pressure switch that your refering to? How do you turn the heater on/off now? You might need the optional remote cable for the pump to interlock it to the heater. You can create schedules right on the pump the 1,2,3 buttion then using the cable, tie that to your heater so when it calls for heat it forces the pump to stay in speed 3.
Yes, i guess you would call it a pressure switch. Currently the power switch on the heater stays on all the time. When the motor runs at low speed the heater does not activate (burners on), but when the pressure switch is pressed the motor bumps up to high speed and the heater activates (burners on) a few seconds later. I always assumed that there is some type of flow meter inside the heater which controls this.

It is an old heater (18+ years) so there is no way to interconnect with the new pump. I plan on replacing this in a couple of years or sooner if it dies.


Mod Squad
TFP Expert
LifeTime Supporter
May 19, 2010
Tucson, AZ
:wave: Welcome to TFP!!!

1) The green is not part of your 220V supply it is strictly the groung. "L2" is usually one of your 220 legs that is always hot. Then "L1" gets the other 220 leg for high speed -OR- "A" gets the other 220 leg for low speed.


TFP Expert
Mar 2, 2011
Your timer should have two incoming lines and two outgoing lines. One of the outgoing lines goes goes directly to the pump and one goes to the pressure activated switch.

The pressure activated switch has one incoming line and two outgoing lines. The pressure activated switch sends power to either high or low by connecting the incoming line to one of the outgoing lines.

You can eliminate the pressure activated switch and just connect the two outgoing power lines from the timer to the pump.

Connect the ground wire the same way as before.


Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
Bedford, TX

If I understand correctly, this is a SuperFlo variable speed pump.. If so, then I would recommend it have constant 220 volt input so that you can use the internal time clock to set up whatever schedule and speeds you want.

The SuperFlo has one feature that you might want to use... It can provide a five volt output that could routed through your pressure activated switch (Assuming it is just a relay and not somehow connected to constant AC power). So you could program the pump to run a schedule and then while you are in the spa, push your air switch and the pump would go to whatever speed you have set up.

This air switch would only allow you to select one speed, but you could still set other speeds at the pump itself.


Jim R.