Choose a Replacement Hot Tub Pump

The most common element that needs replacing on a hot tub is the pump. Most calls into hot tub service providers are due to a problem caused by a malfunctioning pump. If you need to replace a hot tub pump, there are a few things you need to be aware of so that you order the right model.

Pump Problems

You should first understand the anatomy of your hot tub pump when trying to replace it. For help with this, refer to the owner’s manual of your specific hot tub unit. These are the basics:

A hot tub pump has a wet end and a dry end. The wet end houses the impeller and is the side that the water moves through. The impeller is powered by the motor inside the dry end of the pump. The two portions of the pump are separate and it may be possible to just replace the wet end OR the motor, though it’s recommended to replace the entire thing at once.

A failing hot tub pump may show a variety of symptoms.

• If it is making a persistent humming noise, chances are the motor can’t turn. This could be due to a frozen shaft/bearings, jammed impeller, or defective starting capacitor.
• If it’s making a whining noise, the bearings have probably worn down.
• Hot tub seal failure is usually indicated by leaks around the pump, usually forming puddles under it when the seals have gone bad.

Depending on the severity of the problem, It may be a good idea to fix these components individually. However, pump problems usually compound once the unit gets more than a few years old and it may actually be more cost effective to replace the entire unit rather than fix the wearing elements inside.

Here are the things you need to know before replacing a hot tub pump. (You can remove your old unit or refer to the label on the side of it for most of this information.) Some pumps will have valves on either side of the pump, meaning you can close these off and remove the pump without having to drain the hot tub. Other units will require you to empty the water out of the spa before being able to remove the pump.

Pump Speeds

Hot tub pumps are either a 1 or a 2 speed. Check either in your owner’s manual or the AMPS listed on the side of the pump itself. If there’s only one number there, it’s a 1-speed pump. If there are two, it’s a 2-speed.

The other way to find this out is by pushing the button for the jets on your topside panel. If it increases when you push the button twice, then your pump has two different speeds.

Horsepower

Horsepower is what’s necessary to work all of the jets and water elements in your hot tub. This is where the water pressure is powered and you will have more or less pressure depending on the amount of horsepower your hot tub pump has.

Here’s a rule that is a little less rigid than with the other pump elements—the electrical system can typically accommodate the additional amperage. If you want to up the water pressure coming from your jets, you can get a hot tub pump with higher horsepower than the unit that you’re replacing. HOWEVER, if you do decide to increase the horsepower, you only want to move up in increments (or magnitudes) of .5 to 1. For example, if you had a 2 HP hot tub pump, you could bump up to a 2.5 or a 3, but if you had one that was 2 HP, you would NOT want to make the jump to a 5 HP pump. This will result in uncomfortable water pressure and related equipment problems.

Voltage

This is another bit of information that should be in your owner’s manual that will need to match up with the replacement pump. It’s important to find this out because not all spas that are wired for 240V spas use 240Vs—some require 120V. This info can also be found on the side of the pump itself

Frame

The frame is where the bolts fit that attach the wet end to the motor. The number listed on the label should be either 48 or 56. If you can’t find that number for some reason, you can measure for it yourself. Measure between the two through-bolts with a measuring tape; if there are less than 4 inches between the bolts, it’s a 48 frame. If there are 4 inches or more, it’s a 56.

Plumbing Size

The size of the plumbing your water spa that takes the water into and out of the pump is what we’re looking for. It’s common for people to get confused and measure the wet end—don’t do this. Look at the PVC pipe inside the spa and see what the diameter is. This is the size you will want to use when finding a pump and/or pump fittings. Most spas will be the same size for both the intake and outtake pipe, but double check just in case.

Most spa pumps use 1.5” or 2” plumbing fittings.

With all this information in hand, you should be able to select a new hot tub pump as a replacement.