A London leisure centre in summer is a busy old place. Early swimmers at 6.30am, school holiday crowds by ten, a five-a-side league in the evening and somebody's child running round the changing village with one sock on. Through all of it, the showers barely stop. Thermostatic mixing valves in these buildings work harder than almost anywhere else, and summer brings a couple of extra headaches.
How showers are set up in leisure buildings
Leisure centres and gyms tend to use one of a few arrangements, sometimes all of them in one building:
- Group blending valves. One larger thermostatic valve mixes water for a bank of showers, often in a duct or plant space behind the changing room. Handy, but if it drifts, every shower on it drifts too.
- Individual thermostatic shower valves or panels, one per cubicle, common in newer changing villages.
- Timed push-button showers fed from a blending valve. The push button controls flow, the TMV controls temperature.
- Poolside showers, accessible changing rooms and basins, each with their own valve.
Knowing which arrangement serves which shower is half the battle. A good TMV register maps every valve to the outlets it feeds, so when a shower in the women's changing room runs cold, someone knows where to look.
What summer does
Warmer cold water
London's cold mains warms up through the summer, and in a hot spell it can creep up towards 20°C before it reaches the building. Cold water stored in tanks or running near warm plant can get warmer still. HSG274 Part 2 expects cold water to be below 20°C at outlets within two minutes, so a warm cold supply is a Legionella concern in its own right, and one to raise with whoever holds your risk assessment.
It changes how TMVs behave too. With warmer cold water, the valve needs less hot to hit its set point. A valve that was wound up in winter to compensate for cold mains (please don't do this) can end up running hotter than it should in July.
Heavier use
School holidays, swimming lessons and summer camps all mean more showers, more hours of flow and more hard water passing through each valve. More flow means more scale, sooner.
Then quiet spells
Some areas go quiet in summer while others get busier. A sports hall changing room used mostly by school PE groups, for example, might hardly be touched in August. Little-used showers need regular flushing under your written scheme, because the warm water after a TMV is just what bacteria like.
Showers need their own hygiene routine. HSG274 expects showerheads and hoses to be cleaned, descaled and disinfected periodically, with quarterly as the usual starting point. That's separate from TMV servicing, but it's easy to do both at the same visit.
Hard water, hard use
Put London's hard water through a busy group blending valve for twelve hours a day and you get scale in the strainers, scale on the thermostatic element and sticky check valves. The result is temperature wander between busy and quiet times, poor flow at the end of the shower bank and, worst of all, a slower fail-safe response. If you're curious about what goes on inside the valve, our post on hard London water and TMV limescale explains it.
That's why heavily used leisure valves often end up on shorter service intervals than you'd expect. The HTM 04-01 approach is a good guide here: set the interval by how much each valve drifts between visits, and let the records decide.
Fitting servicing around opening hours
Leisure centres open early and close late, and nobody wants a changing room closed on a Saturday. What tends to work:
- Early starts. Getting in before the doors open, or working one changing area while the other stays open.
- Quieter weekdays. Mid-morning in term time is often calmer than any time in the summer holidays.
- Planned closures. If the pool has a maintenance shutdown, that's the ideal time to do the lot.
- Clear signage. A "shower out of use, back by 11" sign saves the duty manager a lot of questions.
This is a lot like servicing a school over the holidays, just in reverse: the school is empty in summer, the leisure centre is full. Our post on TMVs in London schools over the summer covers the empty-building side.
A typical scenario
Imagine a council-run leisure centre in Lambeth with a pool, a changing village of individual cubicles, a dry-side changing room with a bank of push-button showers on one blending valve, and a busy gym. Users have started complaining that the dry-side showers swing from warm to cool in the evenings. On a visit like that, we'd check the hot and cold supplies to the blending valve first, then strip and descale the valve, clean the strainers and check the fail-safe. We'd record readings at several showers on the bank, not just the nearest one, and suggest whether the interval should come down. Showerheads could be descaled and disinfected at the same time, so the centre ticks off two jobs in one early morning.
Gyms and smaller sites
Private gyms, boutique studios and office shower rooms have the same issues on a smaller scale. A couple of thermostatic showers in a basement gym still need servicing, flushing and a record, and they're often forgotten because nobody's job title includes "showers".
Where we work
There are leisure centres and gyms in every borough, with plenty across South London and West London, close to our Chiswick base. Operators running several sites can have them all on one schedule.
The short version
Busy showers, hard water and warm summer mains add up to valves that drift and scale faster. Map every valve to its showers, service on an interval the records justify, keep up with showerhead hygiene and flushing, and plan the work around opening hours. Your members get steady showers, and your duty manager gets a quieter summer.
See TMV servicing for what a visit includes, or installation and replacement if your blending valves are past their best.
Got TMVs in London that need a look?
Tell us roughly what you've got and where. We'll give you a fixed quote and a date that works around your building.