Isolation valves in an O&M manual: how to record every one

The question an occupier asks at the worst possible moment is "where's the stop cock?" Usually it's asked with water coming through a ceiling, at eleven at night, by someone who wasn't on site the day you handed over.

The isolation valves section is the part of a handover manual that earns its keep. Get it right and the occupier shuts the water off in thirty seconds. Get it vague and you get the call instead, and you carry the blame for the damage between the leak starting and someone finding the valve.

This guide covers what to list, what to photograph, and the exact wording that works in a manual for a domestic or small commercial heating and plumbing installation.

What counts as an isolation valve for this section

List anything the occupier might reasonably need to operate, plus anything a future engineer needs to find. In a typical house that means:

• the external stop tap (usually in the footpath or driveway, under a small cover)
• the internal main stop cock
• the gas emergency control valve (ECV) at the meter
• the boiler service valves on flow and return, and the gas cock at the boiler
• cylinder valves: cold feed, secondary return, primary flow and return, and the drain-off
• local valves under basins, behind WC flush plates, at the kitchen sink, to the outside tap
• the underfloor heating manifold loop valves and the manifold isolation valves

In a flat or a small commercial unit add the incoming valve inside the riser cupboard, any landlord-side valve the occupier is not allowed to touch, and the drain-off points.

If the occupier should not operate something, say so in plain words rather than leaving it off the list. "Isolating valve on the incoming riser inside the communal cupboard. Building management access only. Do not use without contacting the managing agent." That is useful. Silence is not.

One entry per valve, and keep the shape the same

Every entry should answer five things in the same order, so the reader learns the pattern by the third one:

1. What it is
2. Where it is, in words someone unfamiliar with the building can follow
3. What it isolates
4. How to operate it, including which way to turn and how far
5. Any warning or note

The location wording is where most manuals fall down. "Under the kitchen sink" is fine in a two-bed flat. In a house with a utility room it is not. Walk the route in your head from the front door and write it the way you would say it on the phone.

A worked example:

Main stop cock — internal

Location: under the kitchen sink, left-hand side at the back of the cupboard, behind the waste trap. Chrome lever, 22mm.

Isolates: all cold water to the property, including the cold feed to the hot water cylinder.

To close: turn the lever a quarter turn so it sits across the pipe, not along it. Closed when the lever is at right angles to the pipe.

Note: open and close this valve twice a year so it does not seize. Hot water will still run warm for a short time after closing; this is normal while the cylinder empties.

That is five lines and it does the job. You do not need prose.

The gas emergency control valve

Write this one carefully and keep it separate from the water valves, with its own heading. The occupier needs to know where the ECV is, that it is the handle at the meter, and that it closes with a quarter turn so the handle sits across the pipe.

Add the standing instruction: if you smell gas, do not operate electrical switches, open windows and doors, turn off at the emergency control valve and call the National Gas Emergency number on 0800 111 999. Put that number in the manual rather than assuming it is on a sticker at the meter, because stickers come off.

State plainly that gas work is restricted to Gas Safe registered engineers and that the occupier should not remove covers or attempt repairs. Your Gas Safe registration number belongs in the manual too, on the front or in the contact details, along with the appliance commissioning details. The manual sits alongside the Building Regulations compliance certificate and the benchmark record; it does not replace them.

Photographs: three per valve, taken in this order

Wide, medium, close. The wide shot shows the room or the cupboard so the reader recognises the place. The medium shot shows the valve in context with a visible landmark — the trap, the boiler case, the meter box. The close shot shows the valve itself, with the handle in the open position, so the reader can compare.

Mark up the medium shot. A single red circle or arrow on the valve turns a confusing photo of a cupboard full of pipes into an obvious instruction. If you only do one piece of mark-up in the whole manual, do it here.

For anything behind a panel, flush plate or access hatch, take a fourth photo with the panel off and say in the text how it comes off. "Flush plate lifts off after pressing the two clips at the top edge" saves someone levering at a tiled wall with a screwdriver.

For the external stop tap, photograph the cover in the ground with enough of the path, kerb or gate in frame that it can be found under leaves in February. Note the depth and whether a key is needed, and whether one was left with the occupier.

A schedule, then the detail

Most manuals read better with a one-page schedule up front and the full entries after it. Keep the schedule short.

Ref	Valve	Location	Isolates
V1	Main stop cock	Kitchen sink cupboard, rear left	All cold water
V2	Gas ECV	Meter box, front elevation	Gas to property
V3	Cylinder cold feed	Airing cupboard, low level	Cold feed to cylinder
V4	Basin service valve	Bathroom, under basin	Basin taps only

Then label the valves on site to match. A printed tag or a marker pen number on the pipe, matching V1, V2 and so on, links the manual to the building. Without labels the schedule is only half the job, and it is the half the occupier can't use.

Wording that keeps you out of trouble

Three habits are worth forming. Say which way a valve turns rather than assuming; slotted screwdriver service valves in particular are closed when the slot sits across the pipe, and plenty of people get that backwards. Say what each valve does not isolate, because the complaint is usually that someone shut a basin valve and expected the whole bathroom to stop. And avoid promises — "helps isolate the basin supply for tap maintenance" rather than guaranteeing a dry job.

Add a short note on seizing. Valves that are never turned seize, particularly older gate valves on cylinder feeds. Tell the occupier to exercise the main valves twice a year, and tell them that a seized valve is a repair job, not something to force.

If a valve is missing, inaccessible or you could not isolate a section cleanly, record that as a limitation. "No service valve fitted to the cloakroom basin at the time of works. Isolation of the cloakroom requires the main stop cock." That is an honest record and it protects you later.

Where this sits in the manual

Isolation valves belong early, straight after the emergency information and before the appliance detail. Nobody reads a handover manual front to back, but they do flick to the front when something is leaking. There is more on the full structure in our guide to how to write an O&M manual, and a ready-made layout in the O&M manual template if you would rather start from a shape that already works.

If you are building these on site rather than back at the desk, we built O&M manual software for exactly that: photos and short notes as you go, one press to tidy the wording, a branded PDF the customer signs on their phone before you leave. You can try it free for 14 days with five reports, no card needed.

On your next handover, walk the property with your phone and photograph every valve wide, medium and close before you pack up. Then write the schedule first, label the pipes to match, and the rest of the section writes itself.