# Hot tub temperature settings explained

Source: https://bubbleandsoak.co.uk/blog/hot-tub-temperature-settings
Published: 2026-10-12
Publisher: Bubble and Soak

**In short:** Most inflatable hot tubs let you set the water between about 20 and 40 °C, and 40 °C is the usual maker maximum. Many owners choose somewhere in the high 30s for a soak. Between uses you can hold a lower temperature, or use the tub's timer or app to start heating ahead of time, following the manual.

The control panel on an inflatable hot tub usually lets you set a target temperature, switch the heater on or off and, on some models, set timers. Picking the right setting is a balance between comfort, energy and how often you use the tub. This guide explains the usual range, the 40 °C limit makers set, typical settings for different uses and how to use timers and a lower holding temperature to save kWh. Always check your own manual, as settings differ between models.

## The usual range and the 40 °C limit

Listings for the tubs in our guides typically give a range of about 20 to 40 °C. For example, several generic tubs state 20 to 40 °C, and the MSpa Denver gives water up to 40 °C. Makers set 40 °C as the maximum, and the controls will not go higher.

The tub's own sensor reads the water near the pump, so the display may differ slightly from the water at the far side. If the reading seems wrong, a floating thermometer gives a second opinion.

| Use | Common choice | Notes |
| --- | --- | --- |
| Relaxed soak for adults | High 30s °C | Below the 40 °C maximum |
| Children in the tub | Lower, as the manual advises | Always supervise; follow the maker's guidance on time and temperature |
| Holding between uses | A few degrees below soak temperature | Saves heat loss; raise before use |
| Summer days | Lower settings | Warm air makes lower water feel comfortable |
| Long breaks | Heater off or low, freeze protection on | Check the manual for frost settings |

Common settings as general guidance

## Choosing a setting for a soak

Most people find somewhere in the high 30s comfortable for a soak, and many start a little lower in summer. Stay below the maximum and follow the maker's guidance on how long to stay in. Hot water combined with alcohol is a poor mix, and anyone with a medical condition or who is pregnant should check with their doctor before using a hot tub.

Children feel heat more and should use a lower temperature for shorter periods, as the manual advises. Always supervise them in and around the tub.

Note: Follow the maker's guidance on water temperature and time in the tub. Keep the cover locked when the tub is not in use, and never leave children unsupervised near it.

## Timers and app control

Many pumps have a heating timer or a power saving timer. Instead of holding the water hot all day, you set the tub to heat so it reaches temperature when you want it. App controlled tubs, such as Bestway's SmartSpa models, the Intex Chevron Deluxe and the MSpa Denver, let you do this from your phone. Our [premium tubs guide](https://bubbleandsoak.co.uk/best/best-premium-inflatable-hot-tubs) covers models with app control.

Remember that heating is slow, often 1 to 2 °C an hour in practice. If you raise the temperature by 5 °C, allow a few hours. Use the [heat-up calculator](https://bubbleandsoak.co.uk/tools/heat-up-calculator) to estimate the minimum.

## Holding a lower temperature between uses

Heat loss is faster when the water is hotter and the air is colder. Holding a few degrees lower between uses reduces losses, and you raise the temperature before you get in. Whether it saves energy overall depends on how often you use the tub and the weather. If you use it daily, holding near your soak temperature is often simplest. If you use it at weekends, holding lower in the week usually makes sense.

In cold weather, do not let the water drop so low that freeze protection is needed unless your manual says that is fine. See [running costs](https://bubbleandsoak.co.uk/blog/hot-tub-running-costs-uk) for how to estimate holding energy.

## Lay-Z-Spa and other brand settings

Most Lay-Z-Spa pumps let you set the target temperature with up and down buttons, switch the heater on and off, and lock the panel. The heater may run the filter pump automatically. Button names, timer features and lock steps vary by pump model, so follow your manual. Intex, MSpa and Wave have their own panels and apps.

[Compare Lay-Z-Spa models](https://bubbleandsoak.co.uk/best/lay-z-spa-models-compared)

## Frequently asked questions

**What is the best temperature for a hot tub?** Many people choose the high 30s °C for a soak. Stay below the 40 °C maximum and follow the maker's guidance.

**Why will my tub not go above 40 °C?** Makers set 40 °C as the maximum, and the controls will not allow higher.

**Should I leave the heater on all the time?** It depends on use and weather. Timers and a lower holding temperature often help between uses.

**Why does the display show a different temperature from my thermometer?** The sensor reads water near the pump. Small differences are normal; large ones may need checking with the maker.

## Buying guides on this topic

- https://bubbleandsoak.co.uk/best/best-premium-inflatable-hot-tubs
- https://bubbleandsoak.co.uk/best/best-inflatable-hot-tubs-for-winter
- https://bubbleandsoak.co.uk/best/lay-z-spa-models-compared