Hot tub glossary

Plug-and-play means a tub designed to run on a standard 120V outlet rather than a dedicated 220V circuit. It avoids the electrician cost — Fixr puts a 220V outlet at $120–$200 with electricians at $40–$100 per hour — but heats much more slowly and generally runs fewer jets at once. That outlet still needs to be a suitable circuit; check the manufacturer's requirements.

Shell is the molded body you sit in, usually acrylic over a structural backing. Skirt or cabinet is the exterior paneling — This Old House prices cabinet materials from $2,000–$9,000 for synthetic wood up to $5,000–$12,000 for brick or faux stone. Equipment bay is the compartment holding pumps, heater, and control pack; access to it determines how expensive service calls are.

Salt cell is the component in a saltwater tub that converts dissolved salt into chlorine. It is a consumable that eventually needs replacing, which is the running cost saltwater buyers most often miss. Fixr puts saltwater tubs at $2,000–$20,000.

Swim spa is a long tub with a current generator for swimming in place — a distinct product at $15,000–$40,000, per Fixr. Cover lifter is the hinged arm that makes removing a heavy cover possible alone; it is close to essential and often quoted separately.

How to choose

Check whether 'plug-and-play' fits your expectations

It saves the 220V electrical cost but heats slowly. Ask how long it takes to reach temperature from cold in your climate.

Ask what the cabinet is made of

This Old House prices cabinet materials from $2,000–$9,000 for synthetic wood up to $5,000–$12,000 for brick or faux stone. It is a real line item, not a finish detail.

Ask what a salt cell costs to replace

It is a consumable in a saltwater system and it is the running cost salt buyers most often overlook.

Make sure a cover lifter is on the quote

Covers are heavy and awkward. A lifter is close to essential and is frequently priced separately from the tub.