Wood fired hot tub maintenance is simpler than most people expect. A quick post-soak tidy, weekly water checks, regular stove cleaning, and a proper seasonal routine are all it takes to keep things running smoothly — and your investment lasting well over a decade.
There's a common assumption that owning a wood-fired hot tub means spending as much time cleaning it as you do soaking in it. That's not quite right. Yes, a natural timber tub needs some attention — but with the right routine, wood fired hot tub maintenance takes minutes, not hours, and it quickly becomes second nature.
Here at Vitru, we stock wood-fired hot tubs built to last. Sustainably sourced cedar, fire-heated water, no electricity required. The whole experience is designed to connect you to the outdoors — and to keep rewarding you season after season, as long as you look after it. This guide covers everything: daily habits, weekly water care, stove maintenance, common problems, and how to prepare your tub for the colder months.
Let's get into it.
What to do after every soak (it takes about two minutes)
This is the one that makes the biggest difference. A quick post-soak routine stops small issues from becoming bigger ones.
- Skim the surface. Leaves, insects, and general garden debris have a way of appearing from nowhere. A quick once-over with a skimmer net sorts it.
- Pop the lid back on. Keeping the cover on when the tub's not in use retains heat, reduces evaporation, and keeps dirt out. Simple, but important.
- Wipe down the waterline. If you or your guests have been using oils, lotions, or sunscreen, a quick wipe before it dries prevents residue building up into a scum ring.
Your future self — particularly the version of you who's about to step into a sparkling tub — will genuinely thank you for this.
Weekly routine: keeping the water fresh
Good wood fired hot tub water care doesn't need to be complicated, but it does need to be consistent.
- Test the water. pH is your main priority. Aim for a range of 7.2–7.6. Water outside this range can irritate skin and, over time, damage metal components. Total alkalinity should sit between 80–120 ppm. Basic test strips or a testing kit make this quick work.
- Top up the water level. Evaporation is perfectly normal, especially after a long soak in cooler weather. Top up with a hose as needed to keep the level consistent.
- Clean the waterline. Even with the post-soak wipe, a weekly pass with a soft cloth prevents residue from setting in and becoming a permanent fixture.
- If your tub has filtration, rinse or replace the filter according to the manufacturer's instructions. A clean filter means cleaner water — full stop.
How to clean a wood fired hot tub properly
A full drain and clean is necessary whenever the water looks cloudy, smells off, or has seen heavy use. For many owners, that's every few weeks; for others, every few months. You'll know when it's time.
Here's how to clean a wood fired hot tub without damaging the timber:
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Drain it fully. Use the drain tap if fitted, or carefully remove the bung. Get the water level as low as possible before you start scrubbing.
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Rinse out debris. Give the interior a quick rinse to remove any loose material before you start scrubbing.
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Scrub the interior. Use a soft brush and a mild, non-abrasive soap solution — nothing harsh, and nothing bleach-heavy that can damage the wood or liner. Work around the full interior, including the waterline and seating area.
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Rinse thoroughly. All traces of soap need to go before you refill. Take your time here.
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Refill with fresh water. Once you're happy it's clean, close the drain and refill.
A quick note on technique: avoid pressure-washing close to timber joins. High-pressure water can work its way into the joins and cause problems. A soft brush and elbow grease is the right approach.
Also: apply linseed oil to the exterior of your wooden tub at least once a year to protect the timber from weathering. But — and this is important — never oil the interior walls. A wooden hot tub relies on water soaking into the timber to swell the planks and create a seal. Oil on the interior stops that process, and the tub will leak.
Do you need chemicals? a sensible take
This one divides opinion. Some owners prefer a low-intervention approach; others like the reassurance of consistent sanitising. Both are valid — it largely depends on how you use your tub.
If you empty the tub after every use, you don't need chemicals at all. Fill, heat, soak, drain. Clean and simple.
If you keep the water for several days or weeks, you'll want to introduce some form of sanitiser to keep bacteria in check. When it comes to wood fired hot tub chemicals — chlorine or bromine are the two most commonly considered options — but there's an important distinction to be aware of. Low-dose stabilised chlorine granules (around 1–3 ppm) are generally safe for wood-fired tubs. Bromine, however, should be avoided if your tub has stainless steel components — including heaters, flues, and fittings — as it causes corrosion even in high-grade steel. Non-chlorine shock (MPS) is a good alternative for multi-day use.
A few practical points worth keeping in mind:
- Always pre-dissolve granules before adding them to the tub
- Don't mix different chemical products
- Encourage anyone using the tub to shower beforehand — it dramatically reduces what ends up in the water
- Always follow the manufacturer's guidance for your specific tub and any products you use
Looking after the stove and flue
The stove is the engine of your hot tub. Look after it, and you'll get faster heat-up times and a cleaner, more efficient burn.
Remove ash regularly. Once the stove has fully cooled, empty the ashpan. Ash builds up quickly and restricts airflow, which affects burn efficiency. The ash itself can be composted or used as garden fertiliser.
Check for soot and tar build-up. Excess soot inside the stove is usually a sign that the wood you're burning isn't dry enough. The best firewood for a wood-fired hot tub is seasoned hardwood with a moisture content under 20% — oak, ash, and birch are all solid choices. Kiln-dried logs are even better. Wet or green wood produces more smoke, more residue, and less heat.
Check seals and connections. Take a moment periodically to look for any signs of corrosion, loose connections, or damage around the stove and flue. Catching something small early is always better than finding it mid-soak.
Common problems and what they're telling you
Seasonal care: Looking after a wood fired hot tub through winter
UK winters bring specific challenges — sub-zero nights, persistent damp, and frost getting into places it really shouldn't. Here's how to approach winter with a wood fired hot tub.
If you're using it through winter: this is one of the great joys of a wood-fired tub, it has to be said. Keep it covered when not in use, increase how often you check the water quality (cold weather slows evaporation but doesn't reduce bacterial activity), and manage debris more actively since it accumulates faster in autumn and winter.
If you're shutting it down: drain everything — and we mean everything. The tub, the stove, any pipework, and heater coils. Even small pockets of standing water will freeze, expand, and cause cracks in metal components. Once drained, dry out the interior as thoroughly as possible to prevent mould, remove any accessories or soft fittings, and cover the tub securely with a breathable, weatherproof cover.
Also inspect the timber for any cracks that appeared over summer, check the straps or bands are tight (this should be done monthly regardless of season), and make sure the chimney is clear of creosote before lighting it up again in spring.
Your maintenance schedule at a glance
Keep it simple, keep it consistent
A well-maintained wood-fired hot tub can last well over 10 years. That's a lot of soaks. The difference between a tub that earns its place in your garden for a decade and one that deteriorates quickly almost always comes down to consistency — not effort. A small routine prevents big clean-ups.
Once you've done it a couple of times, it genuinely becomes second nature. And then the only thing on your mind when you're heading out to the tub is what temperature you want the water.
Ready to invest in the real thing? Explore our wood-fired hot tub range — cedar-built, fire-heated, and made for outdoor living.
Frequently asked questions
How often should I change the water in a wood fired hot tub?
It depends on usage. If you drain after every single soak, no minimum schedule is needed. For tubs kept filled without filtration, change the water every 2–3 days with regular use. With filtration and a sanitiser, you can extend that to every 2–4 weeks. When the water looks cloudy or smells off, that's your signal regardless of schedule.
Can I use chemicals in a wood fired hot tub?
Yes, but carefully. Low-dose stabilised chlorine granules (1–3 ppm) and non-chlorine shock (MPS) are both safe options. Bromine should be avoided in tubs that have stainless steel components, as it causes corrosion. If you drain and refill after every use, you don't need chemicals at all.
What's the best wood to burn in a wood fired hot tub?
Seasoned hardwood with a moisture content under 20% gives the cleanest, most efficient burn. Oak, ash, and birch are all good choices. Kiln-dried logs are even better. Avoid wet or green wood — it burns inefficiently, produces more smoke, and leaves behind more soot in the stove.
How do I prevent my wood fired hot tub from leaking?
A wooden hot tub seals naturally when the timber absorbs water and the planks swell. To support this, never apply oil or sealant to the interior walls. Apply linseed oil to the exterior at least once a year to protect against weathering. Check the bands or straps monthly to ensure they're in good condition and correctly tensioned.
What should I do with my wood fired hot tub in winter?
You have two options: keep using it (in which case, keep it covered when not in use, fire it regularly, and monitor water quality) or shut it down fully. For a full winter shutdown, drain every drop of water from the tub, stove, pipes, and heater coils — standing water freezes and can crack metal components. Dry the interior, cover securely, and inspect the timber for any cracks or loose fittings before storage.