1. Inflatable vs. rigid hot tub — the foundational question

Before you compare brands, answer this: do you want year-round use, or only seasonal?

Inflatable hot tubs (Lay-Z-Spa, MSpa, Intex) cost €350–€2,500, set up in 30 minutes, and suit occasional summer use. Three serious downsides: poor insulation (winter running costs above €200/month), short service life (2–5 seasons), and no real hydrotherapy (air bubbles instead of pressurised water massage).

Rigid acrylic hot tubs cost €6,500–€30,000, last 15–25 years, run year-round (to −25 °C), and offer true massage jets with different profiles (shoulder, back, feet). For regular use, the higher up-front cost is cheaper over the lifetime.

2. What capacity do you actually need?

Capacity is the most important selection criterion — and the most common buying mistake: many buyers go bigger than they need. Rule of thumb: pick the smallest capacity you can fully use 80 % of the time.

An over-sized tub costs more on every heat-up, uses more water at each fill (1,000–2,500 L per change), and needs more floor space. Match the model to your actual usage pattern.

3. Five quality markers of a good hot tub

3.1 Shell material (acrylic class)

Premium outdoor hot tubs use a sanitary-acrylic shell (Lucite XL or equivalent), 4–5 mm thick, UV-stable, multi-ply reinforced. Cheap China imports often have only 2 mm shells with ABS backing — not UV-stable, yellow after 3 years, prone to cracking under hail.

3.2 Insulation (decisive for electricity costs)

Scandinavian full-foam insulation is the gold standard: PU foam fills the entire cavity between shell and cabinet. Result: 30–40 % lower electricity use vs. polyfoam-only models. Wellis has used full Scandinavian foam exclusively since 2018.

3.3 Pump configuration

Rule of thumb: one pump per 2.5 people. A 6-person model needs at least two pumps so two massage sessions can run simultaneously without pressure loss. A separate 24/7 circulation pump keeps water and filter clean.

3.4 Jet count and quality

30–90 jets is the normal range. More is not automatically better — variety matters: rotating jets for deep back massage, point jets for shoulders, large-volume jets for legs. Stainless-steel jets last 15+ years, plastic jets fail after 5–8 years.

3.5 Control system

Modern hot tubs have a touchscreen control panel (Balboa, Gecko, or manufacturer-specific) plus a smartphone app. Important: wired control panel (not Bluetooth/Wi-Fi as the primary control), so the tub remains usable during outages or app updates.

4. Annual electricity costs

Annual electricity for a well-insulated Wellis hot tub: €900–€1,500 in Germany (€0.32–€0.42/kWh), €600–€1,100 in Austria. A heat pump (€2,500–€3,500 extra) cuts this by up to 75 % — to €250–€400/year.

"The biggest electricity-cost mistake is switching off in winter. Residual water freezes in the lines, splits pumps, and costs €1,500–€3,000 to repair." — Sebastian Hill, TwoRelax founder

Energy-saving tips

• Thermal cover R-value ≥ 11 — the biggest heat-loss vector is the top.
• Water temperature 36–38 °C, not above 40 °C (each degree higher = 5–8 % more electricity).
• Heat pump if you use the tub daily — pay-back in 2–3 winters.
• Wind shelter (hedge, screen wall) — reduces convective losses by 15–20 %.

5. Power supply: plug-and-play or three-phase?

Plug-and-play models (Wellis Mars, Callisto, Castor) run on a standard 230 V Schuko socket with a 16 A fuse. No electrician needed, ready immediately. Trade-off: longer initial heat-up (10–14 hours) and heating capacity capped at ~2 kW.

Three-phase models (Wellis Manhattan, Vienna, Olympus) need a 400 V connection with CEE 16 A or 32 A. Advantage: 6–9 kW heating, fast heat-up (4–6 hours), more pump power. Electrician install: €200–€800.

6. Delivery and installation

At TwoRelax, delivery is free across Germany and Austria. Standard: freight truck with lift gate, hand-off at the kerb. Optional white-glove service with crane and garden placement for €600.

Before delivery, prepare the foundation: 15–20 cm reinforced concrete slab (C25/30), 50 cm larger than the tub footprint, load-bearing ≥500 kg/m². Alternative: WPC decking on point foundations. Power within 1.5 m for plug-and-play, or three-phase via electrician.

7. Warranty and service

A serious hot-tub warranty covers 10 years on the acrylic shell, 5 years on the structure, and 2 years on electrical components. Wellis offers these terms as standard. Watch out with overseas brands: many offer only 1 year of warranty in DE/AT because the service logistics aren't there.

8. Wellis vs. Jacuzzi vs. Hot Spring — brand comparison

The three large premium brands differ mainly in price, delivery time, and EU service:

9. Financing: Klarna, leasing, or bank loan?

• Klarna 3 instalments: 0 % APR, interest-free over 3 months.
• Klarna instalment plan: 6–36 months, from 0 % APR (promo periods).
• Bank loan: usually 4–7 % APR — only makes sense above €15,000.

10. The seven most common buying mistakes

1. Tub too big: match capacity to real usage, not aspiration.
2. Ignoring insulation class: demand Scandinavian full foam.
3. Overseas brand without EU service: parts take months, repairs weeks.
4. No foundation plan: concrete slab must be in place before delivery.
5. Switching off in winter: keep running at 36–38 °C.
6. Cheap importer: no TÜV/CE = no EU warranty.
7. Plug-and-play with heavy use: daily use is cheaper with three-phase.

FAQ

How long does a good outdoor hot tub last?

With regular water care and filter maintenance, Wellis hot tubs last 15–25 years. The acrylic shell is the longest-living component; pumps and heater are typically replaced after 10–15 years.

Can I leave a hot tub outside in winter?

Yes — by design. Wellis outdoor hot tubs are rated to −25 °C and should not be switched off. Residual water in the lines would freeze and burst pumps.

Do I need a building permit for a garden hot tub?

In Germany: usually not, if volume < 50 m³ and height < 1.5 m. Property-line setbacks (2.5–3 m) still apply. In Austria, follow the state building code. When in doubt: ask the municipality before purchase.

How often does the water need to be changed?

With proper water care (pH 7.2–7.8, chlorine or active oxygen), every 3–4 months. Rinse the filter weekly, replace it every 12 months.