Most people only call an engineer when something's already broken. But the tubs that last longest around here aren't the lucky ones — they're the ones that get serviced once a year. In a hard-water belt like Dorset, an annual service isn't a luxury; it's the difference between a heater that lasts five seasons and one that burns out in two. Here's what a proper service does, what it costs, and why it pays for itself.
Why Annual Servicing Matters More Here
Our whole patch sits in a hard-water area. Poole, Bournemouth, Christchurch and inland towns like Wimborne and Ferndown are supplied by Wessex Water at around 295 mg/l of calcium carbonate — nearly double the UK average — and even the Bournemouth Water supply over the Hampshire Avon side (Ringwood) is moderately hard. That mineral load is the reason limescale is the No.1 preventable killer of hot tub heaters in this region. (Our full hard water & limescale guide explains the chemistry.)
Every time your tub heats to 37–40°C, dissolved calcium crusts onto the hottest surface it can find — the heater element and flow sensor. Left alone, that scale layer insulates the element, makes it run hotter and longer, and eventually trips it out or burns it up. An annual service descales the element and pipework before that damage accumulates, resetting the clock every year.
What neglect actually costs
A £45–80 annual service vs. what you pay when scale wins:
- Heater element replacement: £80–150 with labour
- Flow sensor replacement: £50–80
- Full pump unit replacement: £150–250
- A new inflatable tub: £300–400+
One prevented heater failure pays for two or three years of servicing.
What's Included in a Full Service
A proper hot tub service is far more than a wipe-down. A typical full service and valet covers:
- Full drain — old water carries months of concentrated minerals, oils and dissolved solids.
- Pipework flush — a line-flush shifts the biofilm that hides in the plumbing and causes smells and cloudy water.
- Element & pipework descale — the big one in a hard-water area; strips scale off the heater and restores efficient heating. (Want to try first? See how to descale a Lay-Z-Spa safely.)
- Filter change or deep clean — a tired cartridge chokes flow and throws E02 flow errors.
- Diagnostic check — heater, pump, jets, flow sensor and controls tested so any developing fault is flagged early.
- Seal & leak inspection — checks seals, hoses and the liner for slow leaks before they get worse.
- Refill & water balance — refilled and balanced (pH 7.2–7.6, sanitiser in range) so it's ready to use.
What a Service Costs
| Service | Typical Cost |
|---|---|
| Full service & valet (inflatable) | £45–80 |
| Descale add-on (with a repair visit) | £30–50 |
| Filter cartridge (part) | £8–20 |
| Service booked alongside a repair | One call-out, not two |
Full pricing for every job is on our hot tub repair cost guide. If you're already booking a fault fix, adding the service to the same visit means you only pay the call-out once.
When to Book a Service
The natural time is spring — as you bring the tub back into heavy use after winter, before the summer season. Our spring startup guide walks through the DIY side, but a full service goes further by descaling and diagnosing at the same time. If your tub is slow to heat, tripping out, or throwing a flow error, don't wait for the annual slot — that's usually scale or a filter, and it's a fault-fix call now. See not heating and not holding temperature.
Local Servicing Across Dorset & the BCP Area
We service inflatable and hard-shell tubs across the whole region and know exactly what the local water does to a heater:
Bournemouth · Poole · Christchurch · Wimborne · Ferndown · Ringwood — or see all areas we cover.