Below are the most common water safety compliance issues, why they happen, and what “fixed” looks like in practice.
Key takeaways
- Most common water safety compliance issues come from weak follow-through: actions not closed out, checks missed, and records scattered.
- Temperature control is still the fastest way to spot systems drifting out of control: keep hot water hot, cold water cold.
- Stagnation is a repeat offender, especially in voids and low-use outlets. Weekly use or flushing is a baseline expectation.
- Legionella sampling is not a “certificate” exercise. It’s used when risk and control performance justify it, and it must be done properly.
- Backflow and poor fittings control can undo good management elsewhere. The legal framework is clear on preventing contamination routes.
Treating the risk assessment as the finish line
What goes wrong: A Legionella risk assessment is completed, filed, and forgotten. Meanwhile, the building changes. A tank is replaced, deadlegs appear after alterations, occupancy drops, or a block goes through long void periods.
How to avoid it: Run risk assessment actions like a maintenance programme, not a report. Review when anything changes in the system and keep a record you can defend if challenged. The assessment should be reviewed periodically, and it’s wise to keep records, even where recording isn’t a statutory duty for smaller landlords.
No clear “owner” for the water system
What goes wrong: Everyone assumes someone else is handling it. Housing management assumes repairs are covering it. Repairs assume a water hygiene contractor is covering it. The contractor assumes the building staff are doing the flushing.
How to avoid it: Put a named responsible person in place and define who does what. ACOP L8 is written for dutyholders who control premises and need a clear management approach to legionella control.
Poor system knowledge: missing assets, hidden deadlegs, unknown outlets
What goes wrong: You can’t control what you can’t map. Common symptoms include unknown tanks, redundant pipework left in place, and “little-used outlets” that are never identified, so they never make it onto a regime.
How to avoid it: Maintain a simple asset list and schematic for communal systems, and update it after works. Removing redundant pipework and keeping water moving are straightforward control measures that keep risk low.
Hot not hot, cold not cold
What goes wrong: Set points drift, plant is tuned for complaints rather than control, return temperatures aren’t checked, and teams rely on assumptions. The result is the danger zone – warm, cold water, lukewarm hot water.
How to avoid it: Use the standard temperature targets as your non-negotiables: keep cold water below 20°C where possible; store hot water at least at 60°C; distribute it so it reaches 50°C within 1 minute at outlets. Then log exceptions and fix them, rather than “re-checking next month”.
Stagnation is ignored during voids and low occupancy
What goes wrong: Voids and low occupancy create stagnant sections of pipework quickly, especially in larger buildings. Flushing becomes “when we remember”, so nothing is provable.
How to avoid it: Put void flushing into the same workflow as lettings and void works. The principle is simple – outlets on hot and cold water systems should be used at least once a week to minimise stagnation, with a suitable flushing regime where non-occupancy is extended.
Flushing and shower cleaning are treated as optional admin
What goes wrong: Logs exist, but they’re not complete. Or they’re completed without the work being done. Or shower heads are never cleaned because they’re inside tenanted homes, and access is hard.
How to avoid it: Build routines that match how housing is actually managed:
- Identify outlets used less than weekly and flush them at least weekly.
- Clean and descale shower heads and hoses at least quarterly.
- Remove deadlegs where practicable.
This is where compliance and resident experience overlap: it’s a hygiene job that also reduces risk.
Confusing Legionella sampling with control
What goes wrong: Sampling gets used as reassurance. Teams chase a “Legionella test certificate” rather than maintaining control measures. Sampling is done at random intervals or by labs that don’t meet the expected standard.
How to avoid it:
- For many hot and cold water systems, microbiological monitoring is not usually required.
- Testing may be needed where there’s doubt about the control regime or recommended temperatures aren’t being achieved.
- Where it’s appropriate, sampling should follow BS7592 and be tested by a UKAS-accredited lab in a proficiency scheme.
TMVs installed, then forgotten
What goes wrong: Thermostatic mixing valves are fitted for scald prevention, but commissioning, servicing, and system temperatures are not managed together. That’s how you end up with safe outlet temperatures but poor system control upstream.
How to avoid it: Treat TMVs as part of the overall control scheme, not a standalone fix. The water supply to the TMV should reach at least 50°C within 1 minute, and hot water should be stored at 60°C at least. If you can’t achieve that upstream, the TMV is masking a bigger issue.
Backflow protection is overlooked during day-to-day works
What goes wrong: A contractor connects temporary equipment, an outside tap is fitted without the right protection, or a cross-connection risk is introduced during refurbishment. It’s easy to miss, and the consequences are not minor.
How to avoid it: Make backflow prevention a hard check in your permits, void works sign-off, and specifications. The Water Supply (Water Fittings) Regulations 1999 set requirements aimed at preventing contamination and waste, including backflow prevention provisions.
Getting ahead of issues across your stock
If you want fewer surprises, focus on two things: repeatable routines and proof. Tie risk assessments to an action log, tie actions to scheduled work, and keep evidence in one place.
If you’re interested in learning how software can help achieve a more efficient and less risky compliance scheme, check out the True Compliance Water Compliance page.
