Winterizing your spa

Xavier Labelle

The original version of this guide was written for Canadian winters, where freezing temperatures and prolonged absences make full spa winterisation a routine task. UK winters are usually milder, and most modern Canadian Spa hot tubs are designed for year-round use here — many UK owners actually use their spa more in winter than in summer. Before reaching for the drill and the wet vac, it’s worth asking whether you really need to shut your spa down at all. If you do, this guide walks you through the process exactly as set out in the owner’s manual.

Should you winterise a hot tub in the UK?

For most UK households, the honest answer is no. A well-insulated spa with a quality cover and a working heater costs noticeably less to keep ticking over through a mild UK winter than people expect, and the frost-protect mode built into modern Balboa control packs will automatically keep the water moving and warm enough to prevent freeze damage even when temperatures drop below zero.

You should genuinely consider winterising your spa only if:

  • The spa is at a holiday let, second home or property you’ll be away from for an extended period (a month or more) over the coldest part of winter.
  • You’re shutting off mains power to the property — frost protection only works if the spa has electricity.
  • Your spa is in a particularly exposed or unheated location (e.g. an unheated outbuilding) and won’t be used at all over winter.
  • You’ve had repeated freeze events that overwhelm your insulation, even with a cover and frost protection running.

If none of those apply, leaving your spa running with a good insulated cover is almost always the cheaper, easier and lower-risk choice — and it means you can use the spa whenever you fancy on the cold, frosty evenings that hot tubs are honestly best for.

What you’ll need

  • Wet/dry shop vacuum (or similar)
  • Sponge or a few absorbent cloths
  • Phillips-head drill bit and a cordless drill
  • Plastic bags or freezer bags
  • Garden hose (optional — useful if you’d rather not drain the water around the spa base)
  • Fine screen mesh (to cover open pipework once the equipment is removed)
  • A tarpaulin or Canadian Spa winter cover for added protection on top of the standard spa cover
  • Your owner’s manual — always the authoritative source for your specific model

Step-by-step: how to winterise your spa

The procedure below mirrors the steps in the Canadian Spa owner’s manual (e.g. for the Toronto hot tub). Always cross-check with the manual for your specific model.

  1. Shut off the power. For a 13-amp plug & play hot tub, unplug it at the wall and seal the plug end inside a plastic bag. For a hardwired 32-amp spa, switch off the breaker on the consumer unit feeding the spa. Confirm the topside panel has gone dark before continuing.
  2. Drain the spa of all water. Open the drain valve on the side of the cabinet and let the water flow out under gravity. A garden hose can be screwed onto the valve to direct the water away from the base if you prefer. Leave the drain valve open throughout the rest of the process.
  3. Clear the air channels (blower-equipped spas only). If your spa has a blower, briefly restore power and run the blower for 10 seconds. This clears residual water out of the air channels.
  4. Shut the power off again. After running the blower, switch the spa off at the breaker (or unplug it) for the remainder of the procedure.
  5. Mop up remaining water. Use a sponge or wet/dry vacuum to remove any standing water from the footwell, seats, filter housing and equipment compartment.
  6. Drain the Control Pack. Disconnect the inlet and outlet unions at the Control Pack and tilt the pack slightly to allow any remaining water to run out. Using a wet/dry vacuum or similar, vacuum residual water out of the uncoupled lines, the pack itself and the pump heads.
  7. Remove the equipment for indoor storage. Remove the motors, pumps, electronics and blowers and store them in a warm, dry place to prevent moisture damaging the units. Leave the topside control in place and seal its wire ends in a plastic bag.
  8. Clear the jet lines. Using a wet/dry vacuum, suck water from each jet and any open line — or use the vacuum’s blow function to push residual water out instead. The aim is no standing water anywhere a freeze could expand and crack a fitting.
  9. Confirm the drain (hose bib) is left open. This stays open all winter so any condensation or moisture can escape rather than pool inside the spa.
  10. Cover all open pipework. Fit fine screen mesh over the open pipes from the motors and control system. This stops insects, rodents and garden debris finding their way into the plumbing while the equipment is removed.
  11. Apply a secondary winter cover. On top of the standard insulated cover, fit a Canadian Spa winter cover or a tarpaulin for added protection from rain, snow and UV through the months the spa isn’t in use.

Important — warranty note

Damage caused by moisture, condensation or any other problems arising from winterising your spa is not covered under the warranty. If you’re in any doubt about doing this yourself, book a hot tub servicing visit and have one of our engineers handle the shutdown for you.

Restarting your spa in spring

Re-commissioning is essentially the reverse of the above:

  1. Remove the secondary winter cover and the screen mesh from the pipework.
  2. Refit the motors, pumps, electronics and blowers you removed for storage.
  3. Reconnect the inlet and outlet unions on the Control Pack and re-tighten any other unions you loosened.
  4. Refit clean filters — replacement cartridges are inexpensive if yours are looking tired.
  5. Close the drain valve.
  6. Refill via the filter housing using a garden hose — this helps minimise air locks in the pump.
  7. Restore power, run the spa through a full priming cycle, and check for leaks at every union before letting the water heat up.
  8. Balance the water chemistry from scratch — alkalinity, pH, then sanitiser — and don’t get in until everything is in range.

Frequently asked questions

Will my spa freeze and crack if I leave it running through a UK winter?

Provided the heater is working, the cover is in good condition and the power supply is uninterrupted, modern Canadian Spa hot tubs handle UK winter temperatures without issue. The bigger risks are a power cut lasting more than a couple of days, a worn-out cover that lets heat escape too quickly, or an undersized heater on a very large spa.

What temperature should I keep my spa at in winter if I’m using it occasionally?

Most owners find it cheaper to keep the spa at its normal soaking temperature (around 38°C) with a good cover than to drop it dramatically and reheat from cold each time — heat-up cycles use a lot of energy. Predictive heating systems further reduce the cost by aligning warm-up with your usage pattern.

Can I just lower the temperature instead of winterising?

If you’re going to be away for one or two weeks, dropping the temperature a few degrees and leaving the cover firmly closed is usually fine. Full winterisation is overkill unless you’re shutting off power or leaving the property for a month or more in the coldest period.

Why does the manual say to remove the motors and electronics?

Even after draining and vacuuming, small amounts of moisture and condensation can sit inside the equipment over a long winter. Storing the motors, pumps, electronics and blowers indoors in a warm, dry place protects them from corrosion and freeze damage — and it’s a manual requirement to keep your warranty valid if you choose to winterise.

What’s the most common winterisation mistake?

Skipping the Control Pack drain step (loosening the inlet and outlet unions and tilting the pack) and leaving the equipment in the spa rather than removing it for warm storage. Both shortcuts are exactly what the manual flags will not be covered under the warranty if damage results.

The simpler answer for most UK owners

Full winterisation is a real maintenance task, and worth doing properly when it’s needed. But for most UK homes, the easier and cheaper route is a quality cover, a working heater, frost protection enabled, and the discipline to check on the spa once a week through the coldest months. If your cover is more than five years old or sagging in the middle, replace it before winter — see our replacement hot tub covers range — and your running costs and freeze risk both drop noticeably.

UK Hot Tub Maintenance and Water Care Guide

After reading Winterizing your spa, owners usually want the next practical step on maintenance, seasonal care, filtration and how to keep water quality stable without making upkeep more complicated than it needs to be.

Canadian Spa Company UK supplies hot tubs, swim spas, saunas, replacement hot tub covers, filters, chemicals and accessories with nationwide delivery. If you want easier long-term ownership, compare filtration, insulation, cover quality and access to service support early, because those details have more effect on running costs than most buyers expect.

For clearer next steps, use the links below to compare ranges, find the essentials for routine upkeep, and book support when needed.

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