To winterize a wood fired hot tub, let the fire go out completely, drain every drop of water from the tub, clear all fittings, valves, and drain points, dry the interior, and cover it securely. If you plan to keep soaking through winter, you'll need a different approach — this guide covers both.
Picture this: you wake up on a January morning, head out to fire up your wood-fired hot tub, and find a web of hairline cracks running through the fittings. The culprit? A small pocket of trapped water that froze overnight and expanded with absolutely zero remorse. It's one of those lessons that only needs to happen once.
The good news is that it's entirely preventable. Whether you're shutting your tub down for the colder months or planning to use it right through winter (honestly, one of the great pleasures of owning one), this guide covers both paths clearly. By the end, you'll know exactly how to winterize a wood fired hot tub, what to watch out for, and how to keep things running safely when the temperature drops.
Do you need to winterize or can you keep soaking?
Before anything else, it's worth deciding which camp you fall into — because the prep looks quite different.
Shut it down if:
- You won't be using the tub for several weeks or more
- Your tub will be exposed to prolonged hard frosts
- Your garden is particularly exposed to wind or sits at higher altitude
- You're going away and won't be around to check on it
Keep operating if:
- You plan to use it regularly throughout winter (weekly or more)
- You're happy to keep an eye on forecasts and act quickly ahead of cold snaps
- You understand the adjustments needed for cold weather use (covered below)
Both are perfectly valid approaches. The key thing is committing to one. Half-measures — like filling the tub, walking away for two weeks, and hoping for the best — are where the damage tends to happen.
What you're protecting (and what winter tends to break)
Understanding the weak points makes the whole winterisation process feel less arbitrary. When water sits in the wrong place and temperatures drop below 4°C, it starts to expand rather than contract. That expansion is what cracks fittings, splits hoses, and causes grief come spring.
The main areas to focus on for good wood fired hot tub winter maintenance are:
- Drain outlets and valves — even a small amount of residual water in a low-lying fitting can cause a fracture
- The stove and any jacketed components — water trapped in the heating system is particularly vulnerable
- Seals and hose connections — frost cycles (repeated freezing and thawing) are especially hard on rubber and plastic fittings
- The cover — if rainwater pools on top and freezes, you'll be dealing with a heavy, awkward ice sheet that can damage the cover and make removal genuinely unpleasant
None of this is scary stuff — it's just physics. Remove the water, and the risk largely disappears.
The quick checklist (for people who love shortcuts)
If you just need the bones of it, here's the full process at a glance:
✅ Let the fire burn out and allow everything to cool fully
✅ Empty the firebox of all ash and soot to help prevent rust over winter
✅ Clean out any debris or build-up from the interior
✅ Drain the tub completely — leave no standing water
✅ Open drain valves and loosen fittings to release any trapped water
✅ Dry the interior and fittings with a cloth; allow to air
✅ Check the stove area and clear any water from internal channels
✅ Secure and dry the cover; ensure it can't pool water
✅ Schedule a quick check after any storm or hard frost
Still with us? Good — here's the expanded version.
How to winterize a wood fired hot tub properly (step by step)
Step 1: let the fire die down and cool completely
Never attempt to drain a hot tub while the stove is still hot or the water is still warm. Wait until the wood fired heater or stove has fully cooled — this is both a safety issue and a practical one, since draining boiling water near frozen ground creates its own problems. In winter hot tub use, trying to rush this step with remaining heat can create avoidable safety issues in freezing temperatures.
Step 2: clean the interior
Give the tub a quick clean while you still have access to the water. Remove any debris, wipe down the walls, scrub if needed, and rinse so no cleaning residue is left behind. You'll thank yourself in spring when you're not reintroducing yourself to whatever was left sitting in there since October. Once the wood surface is clean and dry, apply a protective oil to help protect it over winter.
Step 3: drain every drop
This is the most important step when you're trying to prevent a wood fired hot tub from freezing: drain the water completely by opening the main drain valve and removing the drain plug so the tub can empty fully. Once drained, tilt or check the low points — water loves to hide in corners and low-lying sections of pipework, so check pipes for trapped water and potential leaks before winter sets in. If your tub has an external heater, drain that too, and slightly lift the front of the unit (roughly 5–10 cm) to help any remaining water escape from internal channels. Use a wet/dry vacuum to clear residual water from jets and plumbing where possible. If any plumbing cannot be drained completely, use non-toxic RV/marine antifreeze in those sections.
Leave drain valves open after draining. A closed valve traps residual moisture; an open one lets it out.
Step 4: clear any lines and fittings
If your tub has jet systems, air lines, pipes, circulation lines, or hydro massage features, briefly run them after draining to push out any water still sitting in the hoses. If it has a pump and will stay in use, keep the water circulating to prevent freezing. A small amount left in a line is all it takes to cause a crack. If you plan to shut it down, remove, clean, and store filters and pumps indoors to maintain them over winter.
Step 5: dry and ventilate
Use a cloth to wipe down the interior thoroughly after cleaning, paying particular attention to fittings and metal components so it dries fully and stays suitable for safe bathing when recommissioned in spring. Then leave the tub slightly open — or the cover propped — to allow airflow and prevent any residual moisture from sitting in a sealed, cold environment.
Step 6: sort the cover
Dry the hot tub cover before putting it back on, and use an insulated cover for winter if possible. Make sure it's properly secured so wind can't shift it, and positioned so a heavy-duty insulated hot tub cover helps block snow, ice, and rainwater instead of letting moisture pool in the middle. A cover that collects water is a cover that eventually sags, tears, or freezes solid. Extra insulation at the top also helps retain heat if the tub stays in service through winter.
Wood fired hot tub cold weather use (yes, it's a thing)
For those of us who refuse to let a bit of frost get in the way of a good soak — we see you, and we respect it. Here’s a practical tip for winter hot tub use: a little planning goes a long way. Wood fired hot tub cold weather use is absolutely possible with a bit of planning.
A few things to keep in mind:
- Watch the forecast closely. If a hard frost is coming and you won't be using the tub for several days, treat it like a shut-down situation: drain it rather than leave it sitting.
- Heating takes longer in cold weather. Source water is colder, and heat escapes faster. Budget extra time and use dry, well-seasoned firewood such as oak — it burns hotter and transfers heat far more efficiently than green or damp logs. A winter hot tub without electricity can still perform well, but water temperature needs closer attention in a cold climate.
- Check before you light. Make sure the water level is correct, the stove is clear, and nothing has frozen overnight that could obstruct flow or cause a problem once heat is applied. If the tub has sat in severe cold, start with a small fire so the wood fired heater and water temperature rise more gradually.
- Think about the path to the tub. Ice plus bare feet (or slippers) plus a relaxed post-soak glow is a combination worth addressing before it becomes an incident. A non-slip mat or some salt on the path goes a long way. Clear any snow around the tub before use, too.
Common winter mistakes we see (so you don't make them)
A few classics that come up time and again:
"I'll drain it tomorrow." Tomorrow it freezes. Drain it tonight.
Forgetting the accessories. Floating thermometers, ladles, buckets left outside — anything that holds water and lives near the tub needs to come inside before a hard frost. While you prepare to winterize, remove and clean all filters instead of leaving them dirty in place. Worn seals, hoses, or similar parts should be replaced before freezing weather exposes weak points.
Leaving the cover to collect rainwater. A waterlogged cover left to freeze overnight becomes a genuine problem. Check it regularly and redirect water where you can.
Assuming a light frost won't matter. It usually won't — but repeated freeze-thaw cycles wear on fittings and seals over time. Consistent draining is always the safer habit.
Not checking after storms. High winds can shift covers, deposit debris, and — in particularly grim conditions — leave you with an unexpected puddle in exactly the wrong place. A five-minute check after bad weather is well worth it.
Winter maintenance schedule (five minutes a week)
Winterising isn't a one-and-done job if the tub is exposed to the elements for several months. A brief routine keeps things in good shape:
- Weekly: Check cover tension and positioning; remove any pooled water on top; look for signs of leaks around fittings or drain outlets
- After any frost: Quick visual inspection of fittings and seals before next use, plus a quick look at the chimney and stove area after severe weather, especially if the tub stays outdoors all winter
- After heavy rain or wind: Check that cover straps are secure; clear any debris from around the stove area and drain points
That's genuinely it. Wood fired hot tub winter maintenance doesn't need to be a big production — it's mostly about staying aware and acting quickly when conditions change.
FAQs
Can I leave water in my wood-fired hot tub over winter?
No — not if you're not using it regularly. Once temperatures drop below 4°C, water begins to expand as it cools, which can crack fittings, split hoses, and damage the stove, and that is especially true for cedar hot tubs in a cold climate if they are left unused. Draining the tub completely is the safest option if it'll be sitting unused. Some owners compare this with stock tank setups, but a wood fired hot tub still needs proper winterizing if left full and idle.
What if the tub has already frozen?
Don't try to force it. Allow everything to thaw naturally before inspecting for visible or permanent damage. Check fittings, drain valves, and any jacketed areas carefully before refilling. A cracked fitting or other damaged part will need replacing before the tub is used again.
Do I need to use chemicals during winter?
If the tub is drained and dry, no chemicals are needed during storage. If you're maintaining it through winter with regular use, your usual water care routine applies — though you may find the water stays cleaner for longer in cooler conditions.
How do I stop the cover from sagging?
Position the cover so it has a slight pitch, allowing rainwater to run off rather than pool in the centre. Many covers have a foam dome or supporting structure for exactly this reason. If yours doesn't, a simple frame underneath the cover can help. Check it regularly after heavy rain.
Is it safe to use the tub during a cold snap?
Yes, provided the tub is filled to the correct level, the stove is clear, and there's no ice blocking any components. The main thing to manage is the path and area around the tub — ice underfoot is the more immediate hazard. If a prolonged hard frost is forecast and you won't be soaking for several days, drain it to be safe.
Ready for whatever winter brings?
Winterising a wood-fired hot tub is really about one thing: making sure water isn't hiding anywhere it can freeze and expand. Get the draining right, keep the cover sorted, and do a quick check when the weather turns — and you'll come back to a tub that's in exactly the same condition you left it.
If you're still looking for the right tub to see you through every season, explore our full range of wood-fired hot tubs — built for outdoor living and designed to handle whatever the British weather decides to throw at them.