Despite draining a hot tub being a straightforward task, it can be surprisingly tempting to put it off. However, leaving the same water in your hot tub for too long can lead to cloudy water, clogged filters, poor water quality, and unnecessary strain on your spa’s components.
In this guide, we show you exactly when to drain your hot tub, how to do it safely, and a few simple tips to keep it clean, efficient, and ready to enjoy.
How often should you drain a hot tub?
Hot tub owners should drain and refill their water every three to four months, and more frequently if the tub sees heavy use. Even with the regular use, oils, lotions, and general debris accumulate in the water and pipework over time.
No filters or chemical routines replace the need for a proper drain and clean.
Here are some signs that it’s time to drain your hot tub:
- Cloudy, dull, or discoloured water
- A strong or unusual chemical smell
- Excessive foaming when the jets are running
- Skin or eye irritation after use
- Sanitiser levels that won’t stay balanced, no matter how much you dose
Top tip: Keep a maintenance log of the dates you drain, top up with chemicals, and clean filters. It makes identifying patterns and planning much easier.
What equipment do you need to drain a hot tub?
Draining a hot tub properly requires a small kit of household and hot tub-specific items, plus a little patience. Let’s have a look at those items in more detail:
- A garden hose long enough to reach a suitable drainage point (more on this below)
- A submersible pump, if you want to speed things up
- A non-abrasive cleaner and a soft sponge or cloth
- A wet/dry vacuum, for clearing water from the footwell
- Water test strips, to check chemical levels if you’re planning to drain onto the garden
- A chlorine or bromine neutraliser, if you’re draining onto the garden and levels are still high
How to drain a hot tub step by step
Draining a hot tub is simple: turn off the power, attach a hose to the drain valve, and let the water empty before cleaning the shell and refilling it.
Here’s a breakdown of how to drain a hot tub in seven clear steps:
- Turn off the power at the circuit breaker. This stops the pump and heater from switching on while the tub is low or empty, which could otherwise damage the equipment.
- Remove the cover and take out the filters. They should be out of the way and ready for a separate clean, rather than sitting in draining water.
- Locate the drain valve. This is usually near the base of the shell. Attach your hose or position your submersible pump in the footwell.
- Direct the hose to a suitable drainage point. This could be a foul water or storm drain, or the garden. Check your local council’s rules if you plan to run water onto the garden or a storm drain, since rules around this vary by area.
- Test and neutralise the water first (if draining into the garden). Use test strips to check chlorine or bromine levels, and add a neutraliser if they’re still high so the water’s safe for grass, plants, and wildlife. This step isn’t needed if you’re draining to a foul water drain.
- Open the valve or switch on the pump, and let the water flow out fully. This is the slowest part, so it’s an ideal moment to clean the filters.
- Clear any leftover water from the footwell. Use a wet/dry vacuum or scoop it out by hand.
Important: Draining onto the garden is only suitable if the water’s been tested and dechlorinated, and kept well away from any watercourse, pond, or drain that feeds one (commonly recommended as at least 10 metres). Never let it run onto a neighbouring property, a footpath, or a paved area that drains into a public storm drainage system.
How long does it take to drain a hot tub?
Draining a hot tub typically takes anywhere from twenty minutes to a few hours, depending on the method and equipment used. The table below helps compare the key differences:
| Method | Typical time | Notes |
| Drain valve and garden hose | 2-4 hours | Low effort and hands-off, but slow |
| Submersible pump | 15-30 minutes | Faster, but with a little more setup |
| Wet/dry vac for the footwell | 5-10 minutes | Only clears the last of the water |
Top tip: A pump comes in handy if gravity alone isn’t shifting the water fast enough (or at all).
What should you do after draining a hot tub?
Once the water’s out, cleaning the shell and filters properly sets you up for a fresh, well-balanced refill. Here’s how to do that well:
- Wipe down the interior with a non-abrasive cleaner and a soft cloth or sponge
- Rinse thoroughly with clean water to remove any residue
- Clean the filters separately and replace them if the pleats appear torn, flattened, or if you can’t rinse them clean
- Check jets, seals, and fittings for wear, cracks, or leaks while everything’s accessible.
- Close the drain valve securely before refilling
- Refill with fresh water, run the pumps to circulate it, then test and balance the water chemistry
Top tip: Refill through the filter compartment rather than straight into the shell to help prevent airlocks in the system. If it’s been a while since your last drain, it’s also worth flushing the internal pipework, since biofilm can build up in places a normal drain won’t reach.
Can you leave a hot tub empty?
No, a hot tub shouldn’t be left empty for any longer than it takes to clean, refill, or service it.
Left empty for too long, the shell can dry out and crack, seals can shrink, and the whole structure can warp under changing temperatures.
Stagnant residue in an empty tub can also attract pests or grow algae. If you genuinely need to leave a tub empty, such as over winter, the pipework should be blown clear of water first. The tub should also be securely covered and protected from frost.
Let Cumbria Hot Tub Services drain and clean your hot tub for you
Draining and cleaning your tub properly can be time-consuming. Plus, getting the chemistry, timing, or plumbing wrong can shorten its lifespan. If you’d rather hand over the hassle, Cumbria Hot Tub Services offers routine hot tub servicing across Cumbria, so your tub stays clean, balanced, and ready to use, without the responsibility falling on you.
If you’re unsure of what you need, contact our expert team to guide you in the right direction with no pressure to commit.
