Short answer: HSE's HSG274 Part 2, Table 2.1, says to dismantle, clean and descale shower heads, spray tap inserts and hoses "quarterly or as indicated by the rate of fouling or other risk factors". Quarterly means every three months, four times a year, for every head. Heavy scale or high-risk users can make it more often; the site's risk assessment sets the actual frequency.
Why shower heads are on the list
Legionnaires' disease is caught by breathing in small droplets of contaminated water. L8 lists "a means of creating and spreading breathable droplets, eg the aerosol generated by cooling towers, showers or spa pools" among the risk factors (para 41). It also lists deposits such as scale, sludge and biofilm as a source of nutrients for the bacteria. A shower head brings both together at the point where people breathe the spray.
HSG274 adds that scale deposits "increase the surface area and therefore the potential for microbial colonisation (biofilm formation) and can provide protection from the effects of biocides" (para 2.72).
What "quarterly" covers
| Item | Task | Frequency | Source |
|---|---|---|---|
| Showers and spray taps | Dismantle, clean and descale removable parts, heads, inserts and hoses where fitted | Quarterly, or as indicated by the rate of fouling or other risk factors, eg areas with high-risk patients | HSG274 Part 2, Table 2.1 |
| Electric showers and other low-volume heaters with spray nozzles | Inspect, clean and descale the nozzles as part of the shower head and hose regime | With the shower heads | HSG274 Part 2, para 2.70 |
| Showers not used for seven days or more | Flush until the temperature stabilises, or consider removing the shower | Weekly, or as the risk assessment says | HSG274 Part 2, para 2.77 and Table 2.1 |
| Emergency showers, eyebaths and face-wash fountains | Clean and disinfect shower heads, nozzles, roses and 'Y' strainers | Quarterly, or more often as the risk assessment indicates | HSG274 Part 2, Appendix 6 |
| Emergency showers, eyebaths and face-wash fountains | Flush through and purge to drain, drawing off three to five times the volume of the stagnant zone | As the risk assessment says, but at least every six months | HSG274 Part 2, Appendix 6 |
HSE's web page on hot and cold water systems says the same for ordinary showers: "Dismantle, clean and descale showerheads. This should be carried out quarterly or as determined by risk assessment."
Two points in the wording matter. First, the task is to dismantle and descale, not to wipe the face of the head. Second, the frequency can move with the "rate of fouling": hard water areas and heads that come off heavily scaled are a reason to go more often, and the risk assessment decides.
On the visit
- Work from the list of showers and spray taps in the site's written scheme, so none is missed.
- Remove the head, any insert or flow regulator, and the hose where one is fitted.
- Note the condition as found: light scale, heavy scale, slime or damage. This is the evidence for the "rate of fouling".
- Clean and descale using the method and products in the written scheme, following the product maker's instructions. Replace parts that cannot be cleaned.
- Refit, run the outlet and check it works, keeping spray to a minimum. If the shower has not been used or flushed as the scheme requires, purge the stagnant water to drain without making spray before anyone uses it (para 2.167).
- Record the outlet, date, condition found, what was done and who did it.
Whatever the method, the record must show that every head on the list was done.
Worked example: an office with a staff gym
The building has 8 showers in the gym changing rooms and 6 spray taps in the washrooms. The risk assessment adopts the Table 2.1 frequency unchanged.
- 14 outlets, each done every three months: 56 outlet cleans a year.
- The contractor sets a visit that repeats every 3 months for the descaling, alongside the monthly temperature visit.
- In the first two visits, the 4 showers on the hard water side come off heavily scaled each time. The contractor records this and reports it, and the assessor moves those 4 to a shorter interval.
- One shower in the accessible changing room is used about once a month. It is added to the weekly flushing list kept by site staff, and the assessor is asked whether it should stay (para 2.77).
Who does what
- The dutyholder (the employer, or whoever controls the premises) owns the risk assessment and decides the frequency, with the responsible person (L8, paras 28 and 51).
- The maintenance contractor usually does the quarterly descaling as part of a planned maintenance contract, and reports outlets that foul quickly or are not being used.
- Site staff flush showers that fall out of use each week between visits. See flushing little-used outlets.
- Tenants of rented homes: HSE says landlords should advise tenants "to regularly clean and disinfect showerheads" (HSG274 Part 2, para 2.142).
What to record, and for how long
- Each shower or spray tap by its reference and location
- Date, condition found, method used and parts replaced
- Who did it
- Outlets missed and why, such as a locked room, and when they were done
L8 says records of any monitoring, inspection, test or check, with the dates, are kept "for at least five years" (para 72).
Shower descaling visits in Field Suite
- Contracts: a visit line that repeats every 3 months, with your form attached, creates a job to book a set number of days before each visit is due. A shorter interval for some heads can be its own visit line, set in whole months.
- Build your own form: Field Suite has no ready-made Legionella form. In the form builder, use a repeating group with one row per outlet: reference, condition found (choose one), descaled (pass/fail) and a note. A fail answer marks the form failed and alerts the office.
- Photos and faults: the engineer adds photos of badly scaled heads and records a broken or missing head as a fault found on the visit, which the office can turn into a quote.
See planned maintenance software or book a demo. For every other check on the same system, read Legionella checks for hot and cold water systems.
Questions
Is cleaning the outside of the shower head enough?
No. Table 2.1 says to dismantle, clean and descale removable parts, heads, inserts and hoses.
Do we have to disinfect as well as descale?
Table 2.1 says dismantle, clean and descale for ordinary showers and spray taps. For emergency showers, Appendix 6 says clean and disinfect. Whether the site disinfects ordinary heads too is for its written scheme.
Can we go six-monthly in a soft water area?
Only if the risk assessment says so. Table 2.1 gives quarterly, adjusted for the rate of fouling and other risk factors, and HSE says the risk assessment defines the frequency (para 2.79).
Are electric showers included?
Yes. HSG274 says their spray nozzles "should be inspected, cleaned and descaled as part of the showerhead and hose cleaning regime" (para 2.70).
Field Suite is job management software, not a water hygiene consultancy. The building's own risk assessment and written scheme decide which outlets are descaled, how and how often.
Sources
- HSE, Legionnaires' disease: Technical guidance, HSG274 Part 2 (second edition, 2024), paras 2.70, 2.72, 2.77, 2.79, 2.142, 2.167, Table 2.1 and Appendix 6. https://www.hse.gov.uk/pubns/priced/hsg274part2.pdf
- HSE, L8 Approved Code of Practice and guidance (fourth edition, 2013), paras 28, 41, 51 and 72. https://www.hse.gov.uk/pubns/priced/l8.pdf
- HSE, Hot and cold water systems: things to consider. https://www.hse.gov.uk/legionnaires/things-to-consider.htm
Last checked: 5 November 2026 against the sources above.
Field Suite is job management software for UK building services firms, not a consultancy. Your own risk assessments, contracts and advisers decide what applies to your work. Spotted a mistake? Email info@fieldsuiteapp.com and we correct it.