One pump or two?

Some hot tub have more pumps than other, some pumps in hot tubs are bigger than others. So why is this?

Let’s first take a quick look at what a pump actually does in a hot tub?

Talking about hot tub pumps

The pumps in your hot tub move the water around for three different reasons

Massage – They will supply water at pressure to the jets situated around the hot tub, these then provide you with the hydromassage in the hot tub.
Heating – To enable the water in the hot tub to heat the pump has to move the water over the heating element.
Filtration – A pump will be used to pass the water through the hot tub’s filter which removes dirt and debris from the water.

There are two types of pumps used in hot tubs, power ‘jet’ pumps and smaller circulation pumps which are dedicated to heating and filtration, Similar to your central heating pump.

For this article, we shall won’t cover the smaller circulation pumps as we’re talking about jet pumps here. If the hot tub doesn’t have a circulation pump, then the jet pump will be used instead.

What do the jet pumps do?

As the name suggests, these are the pumps which supply the water to the jets in your hot tub. They vary in size and power but are generally classified by HP (horsepower).

A typical jet pump is between 2 – 3hp.

So what difference does the number of (jet) pumps have in a hot tub?
Well, each pump is designed to supply a certain amount of water. Jets are designed to output a certain amount of water. So a well designed hot tub will match the output from the jet pump to a certain number of jets. The number of jets does depend on the style of jets fitted but roughly is around 20 – 30 jets per pump.

So simply put more pumps means more jets can be fitted to a hot tub.

In a single pump hot tub, all the jets will be driven by one pump. In a two (or more) pump hot tub, Each pump will drive a set of jets or zone which typically is one side of the hot tub.

A bigger hot tub will usually have more than one pump because there is room for more jets, whereas smaller hot tubs make only need a single pump.

Also, you will find ‘low power’ hot tubs (13 amp) models are constricted by the electric supply meaning only one pump can be fitted.

So does that mean more pumps are better?

No, not necessary. There are cases where one pump will be just fine.

Go with the flow

Most single pump hot tub will typically have a control fitted which allows you to move the water to different areas of the hot tub. This will enable you to ‘share’ the power of the pump. Diverting to a specific area of the hot tub will increase the power of those jets as you are sending more water to fewer jets. This works well for uses which hydromassage isn’t a priority and will be using their hot tub for relaxation and recharging.

With two (or more) pumps, each zone is powered by a dedicated pump, so the users can get the power from each pump without having to divert the water away from another area.

Costs

Single pump hot tubs are more straightforward and require less plumbing and of course, pumps, which reduces over costs and ongoing maintenance.

What should I consider when choosing between one or two pumps

Consider how many will be using the hot tub and how you plan to benefit from it.

If just 1 or 2 persons using the tub, then one pump should be fine. You will still be able to get a decent power hydromassage by diverter the water to a single zone of the hot tub.

If there will be more than 2 users and all users of the hot tub will demand the best hydromassage then consider a hot tub with 2+ pumps

The difference between a 1 and 2 pump hot tub

Take a look at two of our best selling hot tubs, both are the same size with matching seating layouts.

We hope this has answered some of your questions when it comes to choosing a hot tub and the number of pumps that it is built with.

If you have any further questions or if we’ve missed anything, please drop us a message.