The Waterway Executive 56 hot tub pump rated for 4HP was referenced as P/N 3721621-1D which has been updated by Waterway with a new model number PF-35-2N22M and new P/N ME-40226-20. The pump feature's 2 speeds, runs on 220-240 volts and is rated for 12.0 amps on high speed and 3.5 to 4.4 amps on low speed. This Waterway executive 56 frame 4.0 HP pump has a side discharge with 2 inch threads and on the intake which measure about 3-1/16" across outside.
Discharge Threads
Referenced as 2 inch for intake and discharge
Actual OD of threads is 3-1/6 inches
Electrical Specs
12.0 Amps high speed (3450 RPM)
3.5 - 4.4 Amps low speed (1725 RPM)
220-240 Volts, 60 Hz
Discharge Position
Ships with discharge at factory default position.
Discharge can be rotated if required, Instruction Video
Compatible Replacement for:
Waterway 3721621-0D
Waterway PF-30-2N22M (With 2" intake)
Waterway PF-40-2N22C (With 2" intake)
Whats Included:
1 x Waterway Pump P/N ME-40226-20
1 x Electrcal cord with amp plug
Cord is about 7ft long with AMP plug
Product Note:
Optional barb P/N 672-4350 Sold Separately
For use in hot tubs only
Questions ? We can help, Contact Us
IMPORTANT
The PF- model number from your old pump should not be used as a reference for selecting a new replacement pump as Waterway has produced up to 4 known variations of pumps with the same model number which are different enough that they are not interchangeable. Always select a replacement pump with the same part number as the Waterway part number on the label on your old pump.
The last digit "C" or "M" in the model number only references the brand of electric motors Waterway uses on these pumps and does not need to be matched on the new replacement pumps. C references Century/A.O. Smith brand motor and M references U.S. Motors brand electric motor on the pump. The low speed amps can also vary depending on the motor brand from 3.5 to 4.4 which has no impact on performance.
Horsepower ratings
Choosing a pump based on Horsepower (HP) can be incorrect. The horsepower listed in your spa manual or on the old pump's label may be overinflated, inaccurate, or even left blank. Horsepower ratings on hot tub pumps are often listed as SPL-HP, BHP, MBHP, RHP or S-HP, which is not the same as continuous operating horsepower. Installing an oversized pump in your hot tub can cause significant damage.
To avoid choosing the incorrect pump, confirm if it’s a 48 frame or 56 frame, then use the high-speed Amperage rating listed on the old pump's label to find the correct replacement instead of the horsepower. The amperage rating is listed with both high/low speed for a 2-speed pump.
Determining hot tub pump thread size
Hot tub pump plumbing sizes are nominal and not the actual outside diameter (O.D.) of the threaded intake or discharge. To confirm your old pump thread sizes, use a tape measure and check the diameter of your old pump thread size.
- 1.5” Pump thread measures approx. 2-3/8” Outside Diameter
- 2.0” Pump thread measures approx. 3” Outside Diameter
- 2.5” Pump thread measures approx. 3-5/8” Outside Diameter
Amperage ratings
New hot tub pump amperage ratings may vary slightly for pumps with the same performance rating. The RPMs remain the same 3450 for high-speed and single-speed pumps and 1725 for low-speed for two-speed pumps.
