At a glance
- Internal stove: usually heats faster, but takes up part of the tub.
- External stove: all the space for bathers, easier cleaning, slightly slower heating.
- Allow roughly 1.5 to 3 hours of heating depending on the model and the season.
Internal or external stove: the comparison
| Internal stove | External stove | |
|---|---|---|
| Principle | Submerged in the water, heats by direct contact | Placed beside the tub, water circulates by thermosiphon |
| Heating time | Often the fastest | Often a little longer |
| Space in the tub | Reduced by one or two seats | Maximum |
| Safety | A guard around the stove is essential | No hot parts in the water |
| Cleaning | Trickier | Simpler |
| Price | Often cheaper | Often slightly more expensive |
As an indication, one manufacturer quotes for example 1.5 to 2.5 hours with an internal stove and 2.5 to 3.5 hours with an external stove for its models: the difference is real, but in the order of an hour.
How to choose a stove
- Output, matched to the water volume: an undersized stove greatly lengthens heating time in winter.
- Material: stainless steel resists corrosion better than mild steel, especially with treated water.
- Glass door: to enjoy the flames, much appreciated in the evening.
- Flue height: a taller flue keeps smoke away from bathers.
What about electric heating?
An electric heater can complement or replace the stove. It is slower, but lets you schedule heating and keep the water at temperature. See our page on electric and hybrid wooden hot tubs.
Frequently asked questions
What wood should I burn in a hot tub stove?
Dry firewood (low moisture content), preferably hardwood. Damp wood heats poorly, clogs the stove and produces a lot of smoke.
Is a hot tub stove dangerous?
The stove and flue get very hot. Internal stoves are generally surrounded by a timber guard to prevent contact. Respect the clearances to flammable materials and never leave children unsupervised.
Can I replace the stove on my hot tub?
Yes, replacement stoves exist. Choose a model suited to the water volume and the type of connection on your tub, and have the manufacturer confirm compatibility.