Legionella risk & water temperature checks in Macclesfield
In short
Legionella bacteria multiply in stored water between roughly 20°C and 45°C. The control is straightforward: keep hot water stored at 60°C and delivered above 50°C, keep cold water below 20°C, and remove dead legs where water sits stagnant. Landlords have a legal duty to assess and control the risk.
Also called: legionella risk assessment · landlord water hygiene · hot water temperature check · water safety check
The numbers are the whole of the control strategy, and they are worth stating plainly. Stored hot water at 60°C. Hot water reaching outlets at 50°C or above within a minute. Cold water below 20°C. Between 20°C and 45°C is the range where the bacteria multiply, and stagnant water in that range is the risk.
That creates an obvious tension with scalding, because water at 50°C causes a serious burn in well under a minute, and at 60°C almost instantly. The resolution is not a cooler cylinder — it is thermostatic blending valves at the outlets where scalding matters, so the stored water stays hot enough to be safe microbiologically while the water reaching a bath or a basin is limited to a safe temperature.
Dead legs are the other half of the problem: sections of pipework leading to outlets that are no longer used, or rarely used, where water sits at room temperature indefinitely. A capped-off pipe left behind after a bathroom refit is a textbook example. They should be cut back to the main run rather than left, and rarely used outlets should be run weekly.
For landlords, this is a legal duty rather than good practice. The requirement is to assess and control the risk of exposure to legionella in the property, which for a typical domestic let means a straightforward risk assessment, keeping temperatures right, removing dead legs, and giving tenants sensible advice about flushing showers that have not been used for a while. It is proportionate — nobody expects a domestic house to be treated like a hospital — but it is not optional.
Void periods matter most. A property standing empty for weeks, then re-let, is the classic circumstance: stagnant water at room temperature, then a shower creating aerosol. Flushing all outlets thoroughly before a new tenancy, or draining down a longer void, is the sensible discipline.
What the job covers
- Hot and cold water temperature checks at cylinder and outlets
- Cylinder thermostat setting and verification at 60°C
- Thermostatic blending valve installation and setting where scald risk exists
- Identification and removal of dead legs
- Straightforward written risk assessment for landlords
- Advice on flushing regimes for void and rarely used properties
What it costs
We don't publish a price for this yet, because a number pulled out of the air is worse than no number at all — your plumber has to honour it. You'll get a firm price for your actual job when they ring you back, before any work starts. The quote itself is free and there's no obligation either way.
Common questions
Do landlords legally need a legionella risk assessment?
Landlords have a duty to assess and control the risk of legionella exposure in their properties. For a normal domestic let it is a proportionate, straightforward assessment rather than an elaborate document — but it does need doing.
Should I turn my hot water down to save energy?
Not below 60°C stored. Lower temperatures let legionella establish in the stored water. Use blending valves to limit the temperature at taps instead — that gives you both safety outcomes at once.
Need this doing in Macclesfield?
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