How to recommission water systems that have temporarily been out of use.
What should you do? This depends on how your premises has been managed over the period of low or no use (such as lockdown). The basic principle of water hygiene management is to keep water moving, maintain adequate temperature control, keep your systems clean and free from microbiological contaminations.
Scenario 1 – If you have continued to manage water turnover during this period by completing regular flushing, temperature monitoring where appropriate and servicing of thermostatic mixing valves and softeners we suggest the following actions:
- Carryout a blow down or purge any debris from the base of the calorifier/ water heater/s.
- Carryout a Thermal disinfection of your hot water services. Ideally by raising the temperature of the whole contents of the calorifier/ water heater/s and circulating water for at least an hour (>70.0◦c). Every hot water outlet throughout the system must then be flushed and, to be effective, the temperature at the calorifier should be maintained high enough to ensure that the temperature at the outlets does not fall below 60 °C. Each tap and appliance should be run sequentially for at least five minutes at the full temperature (but not necessarily at full flow), and it should be measured and recorded.
- In conjunction with the above, you should complete a flush of all cold-water outlets. Each tap and appliance should be run sequentially for at least five minutes at moderate (but not necessarily at full flow), and it should be measured and recorded.
- Descale and disinfect any spray outlets including showers, spray washers and spray taps.
- Inspect cold water storage tanks looking at internal condition and debris. Issues identified should be rectified.
- Consider microbiological sampling from hot and cold-water systems to confirm systems are safe for normal use. Legionella and Drinking water analysis would be recommended.
Scenario 2 – If you have not managed the water turnover or systems during this period, we suggest the following actions:
- Carryout a blow down or purge any debris from the base of the calorifier/ water heater/s.
- Undertake a full system chemical disinfection, while hot water services are off to ensure efficacy.
- Carryout a Thermal disinfection of your hot water services. Ideally by raising the temperature of the whole contents of the calorifier/ water heater/s and circulating water for at least an hour (>70.0◦c). Every hot water outlet throughout the system must then be flushed and, to be effective, the temperature at the calorifier should be maintained high enough to ensure that the temperature at the outlets does not fall below 60 °C. Each tap and appliance should be run sequentially for at least five minutes at the full temperature (but not necessarily at full flow), and it should be measured and recorded.
- In conjunction with the above two points, you should complete a flush of all cold-water outlets. Each tap and appliance should be run sequentially for at least five minutes at moderate (but not necessarily at full flow), and it should be measured and recorded.
- Descale and disinfect any spray outlets including showers, spray washers and spray taps. This should be done before the disinfection.
- Carryout a service inspection, clean and descale on all thermostatic mixing valves.
- Inspect cold water storage tanks looking at internal condition and debris. Issues identified should be rectified.
- Consider microbiological sampling from hot and cold water systems to confirm systems are safe for normal use. Legionella and Drinking water analysis would be recommended.
- If applicable service and disinfect water softeners.
If you have any further queries or questions, do not hesitate to contact the friendly team at Sussex Facilities Management on 01444 812 171, or by using our contact page.
