The Importance of Hot Tub Pumps

A Hot Tub Pumps is one of the most important parts of your spa system. It keeps the water moving, preventing it from becoming stagnant and reducing the amount of chemicals you need to add.

A circulation pump also makes it easier for your filtration system to do its job. It’s an easy upgrade that can help your hot tub be more energy efficient and make water care even easier.


The motor of a hot tub pump is a key component to the whole system. It is what creates the water pressure that pushes the jets and creates the therapeutic massage that we all love so much in our hot tubs. Without a working motor your hot tub would simply sit and be a place for bacteria and grossness to grow.

Basically, the motor is made up of two components, the wet end and the dry end. The wet end contains the impeller that moves the water and the dry end is made up of an electric motor that actually spins the impeller. The motor also has an O ring that seals the pump unions.

When selecting a new hot tub pump you will want to look at the pumps Horse Power rating as well as the Pump Flow Rate and Service Factor. Horse Power is a rating that the manufacturer gives by using the motor size and pump design (impeller size). For example, a 2 HP motor with a designed wet end may be rated as 3 HP.

Flow rate is calculated by the amount of water that moves past a certain point in a given period of time. This is determined by the distance of run of pipe to and from the hot tub and the height changes along the way. This information can be easily calculated by using a few common tools online.


The impeller is the heart of a hot tub pump. It’s a rotating iron or steel disc with curved blades or vanes that create a centrifugal force to push water outward. It also carries the power of the motor to the rest of the unit to create pressure and speed up the flow of water.

The five most crucial factors when selecting an impeller are the flow rate, specific gravity, head, viscosity, and solids content. Flow rate is how many gallons per minute (GPM) the pump can deliver and head is the distance the pump can lift liquid to, often expressed in feet or meters.

Closed impellers have vanes that are surrounded by a shroud to improve efficiency and allow them to handle a certain level of solid waste. They’re commonly used in wastewater treatment, paper and pulp, and mining industries.

Open impellers have open vanes on both sides with no shroud and are best for small to medium sized pumps that don’t operate under significant strain. They can handle a small amount of soft solids, but require a higher NPSH to prevent cavitation and damage.

When installing a new impeller, wet the ceramic portion of the seal set with water to help seat it. Do not use silicone lubricant as this can cause damage to the ceramic. After installation, it’s a good idea to check that the shaft is centered in the housing before tightening the motor bolts. If the shaft is too far out it will rub against the motor and can cause a stripped shaft.

Pump Seals

You might not think about it often, but a hot tub is made up of many essential parts that work together to create your relaxing, therapeutic water experience. Most of these parts are hidden from view, but some, like the spa pump, need special care and attention.

The pump seals separate the “wet end” of the pump — where the pump is inserted into the wet plumbing — from the motor that powers it. A bad seal is one of the most common causes of leaks in the pump. The seals should be replaced any time the pump is taken apart.

Circulation pumps are the heart of a hot tub system, working with your Master Spas EcoPur Charge or ozone filtration to keep your water clean and healthy. These low-flow pumps continuously move the water around your spa, keeping it moving and preventing it from becoming stagnant. This minimizes the need for chemicals, helping you get cleaner water with less effort. The QuietFlo Water Care System is a premium option that works with your spa’s circulation pump to make hot tub ownership easier. It moves 25 gallons of water per minute through your ozone and EcoPur Charge systems, ensuring the water is continually filtered and clean and helps you reduce the amount of chemicals needed. The pump also heats your water more quickly and helps it stay warmer for longer periods.

Pump Frame

The pump is responsible for circulating the water of your hot tub system bringing it to and from your heater, filter and jets. It also provides the power that turns your impeller creating the pulsating force that is sent toward your muscles and relieves those sore joints.

A key to keeping your hot tub working well is keeping your water clean with proper maintenance and using a good quality pump that will last. When your pump begins to show signs of wear or if it’s not delivering the powerful flow of water that you expect from it then a new one is needed.

There are two types of pumps available, a close coupled pump and a frame mounted pump. Close coupled pumps mount directly to the motor without a shaft coupling, which makes them less expensive than their frame mounted counterparts. They also occupy a smaller footprint and don’t require alignment.

Frame mounted pumps mount to the frame of your bike either in a bottle cage or more commonly on your frame itself. These are more popular with mountain bikes but can be used on road bikes as well. They mount using the same mounting bolts as your bottle cage and are often small enough to fit in your jersey or hydration pack.

When selecting a replacement pump it’s important to match the frame size with your existing one to ensure that the bolting pattern is compatible. This can be done by measuring the distance between the “Thru Bolts” that attach to the wet end of the pump.

Leave a Reply

Your email address will not be published. Required fields are marked *