A fair water hygiene contract is priced on three things: how many outlets and assets are serviced, how often someone attends, and how much of the work is bundled into the fee rather than billed as an extra. There is no standard monthly figure, and a flat “from £X a month” headline usually hides more than it tells you.
For most duty holders this is the single biggest recurring Legionella cost. Unlike a one-off risk assessment, it repeats — monthly, quarterly, annually — so a small difference in scope or visit frequency compounds across the year. Scoping it right matters more than shaving the headline rate.
Settle one thing first: a service contract is not, in itself, a legal requirement. The law requires you to control the risk from Legionella, not to hold any particular contract [1]. You can run parts of the programme in-house — daily and weekly checks, flushing little-used outlets — and buy in only what needs competence or kit you do not have. A contract is one way to meet the duty, not the duty itself.
What a good service plan should include
Before you can judge a price, you need to know what falls inside the words “water hygiene contract”. A plan that actually delivers the programme your risk assessment calls for usually contains some mix of:
- Routine temperature monitoring of sentinel and representative outlets — monthly, or as your risk assessment sets it.
- TMV servicing — annual inspection, descale, disinfection and fail-safe test on thermostatic mixing valves.
- Showerhead cleaning and descaling on a defined frequency.
- Cold water storage tank inspection — at least annually, with cleaning or disinfection triggered by what the inspection finds.
- Calorifier inspection and drain-off — annual checks on stored hot water plant.
- Legionella sampling — where the risk assessment requires it, sent to a UKAS-accredited laboratory.
- Flushing of little-used outlets — either delivered by the contractor or, more often, a logged task for site staff that the contractor audits.
- Risk assessment review and logbook upkeep — keeping the written scheme and records current.
Two contracts at the same monthly price can cover wildly different scopes. One might be monitoring-only, with every tank clean, TMV service and sample quoted as an extra; another bundles the annual tasks in. Read the scope before you read the number.
What drives service-visit pricing
A water hygiene quote is mostly skilled time on site, multiplied across the year. Group the drivers into layers and the price stops looking arbitrary.
| Driver | What it covers | What pushes it up |
|---|---|---|
| Visit frequency | How often a technician attends — monthly monitoring plus periodic tasks | Monthly rather than quarterly monitoring; several task visits a year |
| Outlet & asset count | Sentinel outlets monitored, plus TMVs, tanks, calorifiers and showers serviced | Hundreds of outlets, many TMVs, several plant items |
| Scope bundled vs extra | Whether sampling, tank cleans and TMV services sit in the fee or are billed separately | ”Monitoring-only” deals where every task is a variation |
| Site & access | Number of sites, travel, occupied wards or rooms, out-of-hours work | Dispersed estates, secure or 24/7 sites needing evening visits |
| Reporting & records | Depth of reporting and how records are delivered | Full digital logbook upkeep and management-level reporting |
Read those as three buckets. The planned core is frequency × asset count — the predictable spend you can estimate from your own building. Friction sits in access and dispersed sites, which inflate a quote quietly. And the line most buyers miss is scope: a cheap monitoring-only monthly fee can cost more across the year once every sample, tank clean and TMV service lands as a separate invoice. For the lab side of that, the How much does Legionella water testing and sampling cost? breakdown shows how sampling spend stacks up, while the underlying How much does a Legionella risk assessment cost in the UK? sets the scope this contract then has to deliver.
Where remote monitoring offsets visit cost
Here is the part worth thinking hardest about. A large share of a monthly contract is the temperature-monitoring visit — a technician attending mainly to take sentinel temperatures and write them down. Those readings are exactly what continuous, automated sensors are built to capture [3].
Remote monitoring offsets cost by changing what the contractor has to attend for. If sentinel temperatures are logged automatically, the visit whose only job was to read them becomes harder to justify, and the contractor’s time can refocus on tasks that genuinely need hands on site — TMV servicing, tank and calorifier inspection, sampling and remedial work. Fewer attend-to-read visits can mean a leaner, cheaper visit schedule, and continuous data also flags a drifting temperature between visits rather than at the next one.
Frame this honestly: it is a real driver, not a guaranteed saving. Whether it actually reduces your bill depends on how the contract is structured — a monitoring-heavy deal renegotiated around automated data behaves very differently from one where monitoring was already a minor line — on the capital or rental cost of the sensors, and on the fact that physical tasks still need a competent person on site. The win is sharpest where manual monthly monitoring across many outlets or several sites dominates the cost, and weakest where the contract is mostly annual plant servicing. Price the contract and any monitoring together, as one decision, not in isolation.
How to compare quotes and justify the spend
Put every quote on the same footing before you read the number. Ask each provider:
- Is this monitoring-only, or does the fee include the annual tasks — TMV servicing, tank inspection, calorifier checks, showerhead cleaning?
- What is the visit schedule, and what specifically happens at each visit?
- Are Legionella samples and any tank cleans in the price, or billed as variations?
- How many outlets and assets is the quote based on, and does that match your asset register?
- Is the provider on a recognised scheme such as the Legionella Control Association, working to a documented code of conduct [4]?
- How are records delivered — a paper folder dropped after each visit, or a live digital logbook you can audit at any time?
A quote that answers those cleanly, even at a higher monthly figure, is usually better value than the one that does not, because the gaps reappear later as variations. The discipline that keeps a contractor accountable from day one — a clear scope, defined deliverables, evidence at every visit — is what Working with contractors: ensuring Legionella compliance turns on, and it is exactly what The Legionella Control Association Code of Conduct explained sets out to formalise.
To justify the spend internally, frame it against the risk assessment, not against last year’s invoice. The contract delivers the controls your assessment identified; trimming it below that scope does not save money, it transfers the cost to an audit finding or an incident.
This is general guidance to help you scope and compare a contract, not a specification for your building or a price you can hold a contractor to. What your plan must contain, and how often each task runs, are decisions for a competent person working from your site-specific risk assessment — not from any list or figure here [1][2]. Nothing here is legal or design advice.
What a contract typically costs
Recurring pricing varies more than almost any other Legionella line, so treat these as the shape of the market rather than a quote, and confirm in writing against your own asset list.
- A small, simple single site — a few sentinel outlets, one or two TMVs, no stored hot water — sits at the bottom of the market: a modest recurring monitoring charge plus a handful of separately-priced annual tasks.
- A mid-sized building with stored hot water, a calorifier, several TMVs and a few dozen outlets carries a higher monitoring fee and a fuller annual schedule, with the yearly total typically running into the hundreds.
- A large or multi-site estate — hundreds of outlets, multiple plant rooms, dispersed buildings — runs into four figures a year and beyond, where visit frequency, asset count and travel dominate.
These describe the shape of the spend, not a figure for your site. Where it lands depends on your asset list and your visit schedule, which is why a written quote built against a shared asset register beats any phone estimate.
What to do this week
Pull your asset register and risk assessment together and write a one-page brief: the number of sentinel outlets, the TMVs, tanks, calorifiers and showers, the visit frequency your assessment calls for, and which tasks you already cover in-house. Send that identical brief to every provider you ask. Quotes built on the same scope are comparable; quotes built on a guess are not — and that single page is also what tells you whether automated monitoring could take the routine temperature reads off the visit schedule before you sign for another year.
FAQ
Is a water hygiene contract a legal requirement?
No. The law requires you to control the risk from Legionella and to act on a suitable risk assessment, but it does not require any specific contract [1]. A contract is a common and practical way to deliver the controls, especially where you lack the competence or equipment in-house, but parts of the programme — flushing, weekly checks, basic record-keeping — can be done by trained site staff.
What is a fair frequency for monitoring visits?
There is no fixed legal interval. Monitoring and sampling frequency are set by your site-specific risk assessment, driven by the systems you have and how they are used, rather than by a universal monthly rule [1][3]. Monthly sentinel-temperature monitoring is common, but a low-risk simple site may justify less, and a complex or high-risk site more. Match the contract to the assessment, not to a default.
Can remote monitoring replace my contractor entirely?
Not entirely. Continuous sensors can capture the temperature readings that a monitoring visit existed to take, which can reduce attend-to-read visits and their cost [3]. But TMV servicing, tank and calorifier inspection, sampling and remedial work still need a competent person on site. Treat monitoring as a way to refocus and lean out the visit schedule, not as a full substitute for the service.
Sources
[1] HSE, “Legionnaires’ disease - what you must do”. https://www.hse.gov.uk/legionnaires/what-you-must-do/index.htm [2] HSE, “Legionnaires’ disease: Technical guidance (HSG274)”. https://www.hse.gov.uk/pubns/books/hsg274.htm [3] HSE, “Testing and monitoring your water system for legionella”. https://www.hse.gov.uk/legionnaires/testing-monitoring-water-system.htm [4] Legionella Control Association, “Code of Conduct for Service Providers”. https://www.legionellacontrol.org.uk/