Why you should not switch off in winter

1. Frost damage in lines

When you switch off and drain the tub, residual water remains in pumps, the heater circuit, and jet lines. This residual water freezes at sub-zero temperatures and expands by 9 % — enough to split plastic unions, crack pump housings, and destroy the heater. Typical repair cost: €1,500–€3,000.

2. Electricity cost of re-heating

If you re-fill in spring and heat to 38 °C, you spend €60–€120 in electricity for the initial fill (1,500 L from 8 °C to 38 °C). If you instead keep it at temperature, winter costs you only €30–€80/month above summer use — and the tub is usable any time.

"A continuously-running hot tub with a good cover uses less electricity in winter than a tub that's switched off and re-heated in spring." — Sebastian Hill, TwoRelax founder

The 6-step procedure

1. Top up to maximum water level

   Add water until the "Max" mark at the skimmer is reached. A full tub has more thermal mass and cools more slowly. High water level also prevents the pump from drawing air.

2. Hold temperature at 36–38 °C

   Set the temperature to 36–38 °C and leave the tub running continuously. Lower temperatures (e.g. 30 °C "winter eco mode") are not recommended: every heat-from-cold costs disproportionately more electricity, and the water isn't ready when you want to use it.

3. Lock the thermal cover (R-value ≥ 11)

   The cover is the most important winter component. A standard cover with R-value 8 loses 30 % more heat than a premium cover with R-value 11. Tighten all straps — wind can lift the cover and let warmth escape. For snow: sweep with a soft brush, never shovel.

4. Activate freeze protection

   Wellis hot tubs have a built-in Smart-Winter function: when the water drops below 4 °C, the pump automatically runs every 15 minutes for 2 minutes to keep lines clear. Active by default — check under "Settings → Winter Mode".

5. Add a heat pump (optional)

   An air-to-water heat pump for hot tubs costs €2,500–€3,500 (€200 install) and cuts winter electricity by up to 75 %. Instead of €80–€120/month you pay only €20–€35/month. Pay-back: 2–3 winters at German prices.

6. Weekly visual check

   Once a week: cover lock tight? Water level still on max? Visible ice at water edge? Rinse filter every 2 weeks. After snowfall: keep cover surface clear (no ice load), keep access path de-iced.

When IS switching off the right call?

Three scenarios where full winterising is sensible — in each case, hire a professional:

• Holiday property without winter power: if the building is fully un-powered through winter.
• Sale or move: if the tub will stand unused for more than 6 weeks.
• Major repair: if a component needs to be replaced that shuts down the whole unit.

Proper winterising includes: complete drainage, vacuum-removal of all line water with an industrial vac, filling heater and pump with food-grade propylene-glycol antifreeze, and full filter removal. Pro service cost: €250–€450.

Common winter problems and solutions

Problem: water cools despite the cover

Causes: leaky cover seal, R-value too low, damaged side insulation. Solution: tighten straps, inspect cover for splits, replace if needed (€350–€600).

Problem: higher-than-expected electricity

Most common cause: temperature set too high (40 °C vs. 38 °C = +20 % electricity). Other causes: poor placement (wind-exposed, no hedge), older variable-speed pumps. Solution: heat pump retrofit.

Problem: ice build-up on cover surface

Snow: soft-brush off, never shovel (damages the vinyl). Ice: do not pour hot water (thermal-stress crack risk) — let the sun do the work.

Winter water care

• Chlorine dose: 20–30 % less than in summer (water stays cleaner).
• pH: still 7.2–7.8 (test weekly with strips).
• Water change: every 3–4 months — in winter, best between February and March.
• Filter: rinse every 2 weeks, full replacement every 12 months.

FAQ

Down to what temperature is a Wellis hot tub winter-proof?

All Wellis outdoor models are rated to outside temperatures of −25 °C. No region of Germany or Austria regularly falls below this.

What does winter operation cost vs. summer?

Winter extra: €30–€80/month (no heat pump), €10–€25/month (with heat pump). Total December–February: €90–€240 (no HP), €30–€75 (with HP).

Can I use the tub in winter exactly like in summer?

Yes. Many Wellis owners say winter use is the most enjoyable: 38 °C water, cold air, snowflakes in the wind. Just close the cover immediately after use to retain heat.