4HP / 3HP / 2HP - One-Speed - Balboa Ultimax Spa Jet Booster Pump - Ultima Vico

Genuine Balboa Ultimax / Ultima / Vico Spa Jet Booster Pumps. This is the 2HP & 4HP 1-speed pump. Both 1 and 2 Speed versions available. These supersede the older SuperWow pumps. Balboa Water Group GG Industries. Comes standard with AMP plug. 

Replaces superseded part numbers: 1023032, 1023130,1038301, 1023031, 1038400, 1038200, 1038401, APUMU4153A, APUM401533, APUM40156A, and others. 

Versions:

• 1-Speed Pumps (Labelled 2HP/3HP/4HP)
• 2-Speed Pumps (Labelled 2HP/3HP/4HP)
• 2-Speed Pump (Labelled 1.5HP) (uncommon)

Installation Notes if Replacing a SuperWow pump:

• Use lubricant on pump thread due to a variance of the thread. Newer pumps have a tigher thread.
• Plumbing side is very similar, but in some cases it will need to be modified.
• Motor mount is different. Remove mounting studs in spa and mount motor as necessary.

Balboa Pumps marked "4HP" & "3HP" are actually a 2HP pump in Australian spas. See notes below for explanation. 

These are a very common pump found on many Spa Industries' brands of spas. (Bullfrog, Signature, Leisurite, Designer, Lanark, SCS Industries, etc)  They were often 2-speed pumps with the low-speed wire clipped off, thus actually becoming single speed pumps. If your plug has one wire clipped off, ensure the new pump has the same done! 

Dimensions:

• 2HP / 3HP / 4HP Two-Speed: Length: 395mm / Height: 232mm / Width: 195mm
• 2HP / 3HP/ 4HP One-Speed: Length: / Height: / Width: 195mm
• 1.5HP Two-Speed: Length: / Height: / Width: 195mm
• 2"/50mm FBT Thread - measures ~78-79mm OD on pump

 Important Notes: 

• Some Spa Manufacturers use a complicated & confusing form of Horsepower measurement that was more commonly used in the USA, called hydraulic horsepower (HP=PSI*GPM/1714). It gives a more impressive appearance, and may give a false impression of performance. But there's more!
• Standard Australian HP ratings are calculated purely on input power in Watts, which are then converted to HP. (1HP=745.7Watts). 
• Balboa & Aquaflo have both released pumps to spa manufacturers that use these confusing power ratings at the request of Spa Manufacturers. 
• You can always measure (with an Amp Meter) the input current and convert back to real HP.
• Rough HP measurement can also be calculated using Ohm's Law (V=IR).   These pumps also have an Amperage rating that can be roughly converted back to Watts, and then to Horsepower. The problem here, is the spa manufacturers used some slightly misleading ratings here as well, eg, they'd use a locked-rotor Amperage draw, etc. You'll see how the Amperage ratings and the HP labels don't match up.
• Furthermore, HP ratings are not an ideal measurement of pump performance anyway! Pump flow curves, which measure flow per metre of head pressure are a far more reliable method of measuring pump performance, especially with the advent of variable-speed DC motors.
• Basically the labels can be totally misleading in regards to the pump's actual HP. Balboa is an OEM that will label to reflect whatever the spa manufacturer wants.