Servicing TMVs in London schools over the summer holidays

Ask a London site manager about the summer holidays and you'll get a wry smile. The pupils go home, and the building fills up with roofers, decorators, IT installers and someone repainting the hall floor. Somewhere in that six-week scramble, the TMVs need doing too. Plan it now and it's painless. Leave it until mid-July and it's a squeeze.

Why schools have so many TMVs

Schools are full of hot water outlets used by people who can't be expected to judge a safe temperature for themselves. Think nursery and reception toilets, pupil washbasins, accessible toilets, changing rooms, food tech rooms and the medical room. Most London schools limit the hot water at outlets pupils use, and a thermostatic mixing valve is the usual way of doing it. A typical primary can easily have a few dozen. A big secondary or an all-through academy can have far more, spread across buildings of every era from Victorian board school to last year's extension.

Your water safety arrangements, Legionella risk assessment or local authority guidance will set the temperature each outlet should run at. Our job is to make sure every valve actually delivers it, and still shuts off safely if the cold supply fails.

Why the summer holidays are the right time

• Empty washrooms. We can isolate a whole block of toilets for an hour without a queue of Year 3s forming outside.
• No safeguarding juggling. Working in pupil toilets during term needs a lot of care. In the holidays, it's just plumbing.
• Time to replace what fails. If a valve is obsolete or won't pass its fail-safe test, there's time to order and fit a replacement before term starts.
• It sets up the year. Valves serviced in August are on a clean slate for the busiest months of use.

Half terms and Easter work too, especially for smaller schools or for six-monthly intervals. But the long break is the only window where you can get round everything without anyone noticing.

The other summer problem: six weeks of still water

Here's the catch. An empty school is a building full of water that isn't moving. And July and August are when London's cold mains is at its warmest, sometimes creeping up towards 20°C before it even gets into the building. Warm, stagnant water is what Legionella likes, and the mixed water between a TMV and its outlet sits in exactly the temperature range bacteria do best in.

So the holiday needs a water plan as well as a servicing plan:

• Keep little-used outlets on your flushing regime if the site is staffed over the break. HSG274 Part 2 expects infrequently used outlets to be flushed regularly, and your written scheme will say how often.
• Remember that contractors on site may be draining down or isolating parts of the system. Make sure someone knows which bits have been off, and for how long.
• Before pupils come back, flush the system properly and check hot and cold temperatures at your sentinel outlets.

This ties in nicely with TMV servicing. If we're working in the last week or two of the holiday, every valve gets run, cleaned and checked just before the building fills up again. If you'd like that timing, say so early, because the last fortnight of August is the slot everyone wants.

How a school visit usually runs

Every school is different, but a typical summer visit looks like this:

1. Agree the plan. We go through your TMV register, or build one if you haven't got one, and agree which blocks we do on which days around the other summer works.
2. Sign in, get keys, find the caretaker. We'll follow your site rules and safeguarding policy for visiting contractors. If you need anything specific from us, tell us before the day.
3. Service every valve. Temperatures recorded before we start, strainers and check valves cleaned, the cartridge descaled, the set temperature checked and the fail-safe tested. London water being what it is, there will be scale.
4. Label and record. Each valve gets an ID that matches the register, with its location and next due date.
5. Report back. You get certificates for every valve and a priced list of anything that needs replacing, in time to sort it before September.

A typical scenario

Imagine a two-form-entry primary in Enfield with a 1930s main building, a 2000s nursery block and a newer extension. Nobody's quite sure how many TMVs there are, because the last list was written before the extension went up. In a case like that, we'd suggest a short survey visit in June, so the summer servicing can be quoted properly and any obscure valves can have parts ordered in advance. The service itself could then be done over a couple of quiet days in August, with replacements fitted before the inset days. The school starts the year with a complete register, a certificate for every valve and a date for the next round.

London quirks worth thinking about

Summer is also when the roads around schools are quieter, which makes parking easier than in term. It's not a free-for-all though. Many inner London schools sit in controlled parking zones, and some have no on-site parking at all. If you can let us use the staff car park while it's empty, that helps.

We work with schools right across the capital, including the big school estates in North London and South London. Academy trusts with schools in several boroughs can have them all done in one programme, grouped by area so we're not crossing the river more than we need to.

The short version

Use the summer holidays for TMVs. Book in the spring, plan around the other contractors and the Legionella risk from standing water, and aim to finish close to the start of term. You'll hand back washrooms that are safe, recorded and ready for September.

More on what a service involves on our TMV servicing page. And if your school also shuts over Christmas, our winter TMV guide covers that shutdown too. With London's water, it's worth reading up on limescale and TMVs as well.