How do you decommission/recommission a void property?

The de-commissioning and re-commissioning of a property during periods of non-occupancy

 

All buildings containing a domestic hot, cold or both domestic water services, which are to be unoccupied for any long term period, should be de-commissioned into safe storage.

The Process

Long Term (more than 12 weeks)

De-commissioning

All buildings containing a domestic hot, cold or both domestic water services, which are to be unoccupied for any long term period, should be de-commissioned into safe storage using as a minimum the following procedures.

  1. Place notices on all entrances and exits explaining that the building will have no water services until re-commissioned by IWS (leaving contact names and numbers).
  2. Contact service suppliers (water/gas/electricity) prior to commencement of works for any special instructions or action to be taken.
  3. Isolate any electrical supplies to Calorifier immersions or electric water heaters.
  4. Isolate any LPHW secondary pumps feeding any Calorifiers.
  5. Flush all soil/foul pipework with clean water prior to drain down of the systems.
  6. Drain down any water storage vessels, this includes cold water storage tanks and Calorifiers.
  7. Ensure that soil/foul connection to the main sewer is plugged to prevent gassing off into building.
  8. Isolate the incoming main placing a warning notice of the procedures in place.
  9. Issue report for client to file in the site logbook.

Re-commissioning

All buildings containing a domestic hot, cold or both domestic water services, which have been unoccupied for any long-term period, should be re-commissioned using the following procedures.

  1. Survey the system to make sure it is safe to re-instate the services.
  2. Contact service suppliers (water/gas/electricity) prior to commencement of works for any special instructions or action to be taken.
  3. Reinstate connection of soil/soul pipework to the main sewer.
  4. Check water storage tanks for internal condition and clean if required.
  5. Turn on the incoming mains; flush the cold water pipework whilst checking for any leaks.
  6. Check the cold water storage tanks /mains fed Calorifiers for correct filling.
  7. Prime the Calorifiers and hot water systems and bleed out any air.
  8. Chemically disinfect the system dosing the incoming main, cold water storage tanks and Calorifiers, drawing the chemical through all outlets.
  9. Re-instate electrical supplies to all water heaters, turn units on and check for temperatures of 60oC.
  10. Re-instate LPHW supplies to Calorifiers and check flow and return temperatures to make sure they conform to standards. (60oC on the flow and a minimum of 50oC or 55o in healthcare on the return).
  11. Re-calibrate all TMV’s to a maximum outlet temperature of 43oC (if installed).
  12. Remove any warning notices.
  13. Take a bacteriological sample from several outlets on the system to confirm that the disinfection process has been successful.
  14. Issue works report, disinfection certificates and sample analysis report to the client for filing in the site log book.

 

Short Term (4-12 weeks)

De-commissioning

All buildings containing a domestic hot, cold or both domestic water services, which are to be unoccupied for a short term period of 4 to 12 weeks, should be de-commissioned into safe storage using as a minimum the following procedures:

  1. Place notices on all entrances and exits explaining that the building or flat has had its water services de-commissioned and that any water discharge should be carried out in a controlled manner by a competent person.
  2. Systems should not be used until re-commissioned by IWS (leaving contact names and numbers).
  3. Isolate any electrical supplies to Calorifier immersions or electric water heaters.
  4. Isolate any LPHW secondary pumps feeding any Calorifiers.
  5. Flush all soil/foul pipework with clean water on a weekly basis and record.
  6. Flush all cold water pipework and outlets on a weekly basis and record.
  7. Isolate the incoming main placing a warning notice of the procedures in place between flushing visits.
  8. Issue weekly flushing report for client to file in the site log book.

Re-commissioning

All buildings containing a domestic hot, cold or both domestic water services, which have been unoccupied for a short term period of 4 to 12 weeks, should be re-commissioned using the following procedures.

  1. Survey the system to make sure it is safe to re-instate the services.
  2. Check water storage tanks for internal condition and clean if required.
  3. Turn on the incoming mains; flush the cold water pipework whilst checking for any leaks.
  4. Flush all soil/foul pipework with clean water.
  5. Check the cold water storage tanks /mains fed Calorifiers for correct filling.
  6. Flush the Calorifiers and hot water systems and bleed out any air.
  7. Chemically disinfect the system, dosing the incoming main, cold water storage tanks and Calorifiers, drawing the chemical through all outlets.
  8. Re-instate electrical supplies to all water heaters, turn units on and check for temperatures of 60oC.
  9. Re-instate LPHW supplies to Calorifiers and check flow and return temperatures to make sure they conform to standards. (60oC on the flow and a minimum of 50oC or 55o in healthcare on the return).
  10. Re-calibrate all TMV’s to a maximum outlet temperature of 43oC (if installed).
  11. Remove any warning notices.
  12. Take a bacteriological sample from several outlets on the system to confirm that the disinfection process has been successful.
  13. Issue works report, disinfection certificates and sample analysis report to the client for filing in the site log book.

 

Very Short Term (less than 4 weeks)

Properties that are to be unoccupied for a period of less than 4 weeks should have the following procedure carried out during the period when not in use.

  1. Place notices on all entrances and exits explaining that the building or flat has had its water services de-commissioned and that any water discharge should be carried out in a controlled manner by a competent person.
  2. Systems should not be used until re-commissioned by IWS (leaving contact names and numbers).
  3. Flush all soil/foul pipework with clean water on a weekly basis and record.
  4. Flush all hot and cold water pipework and outlets on a weekly basis and record.
  5. Isolate the incoming main placing a warning notice of the procedures in place between flushing visits.
  6. Issue weekly flushing report for client to file in the site log book.

N.B. Carry out this process until the building is brought back into use, or if the building is going to be unoccupied for a further extended period, follow the appropriate process contained within the procedure.

Properties that are to be unoccupied for a period of less than 4 weeks should have the following procedure carried out immediately prior to the new occupants moving into the property.

  1. Survey the system to make sure it is safe to re-instate the services.
  2. Check water storage tanks for internal condition and clean if required.
  3. Turn on the incoming mains; flush the cold water pipework whilst checking for any leaks.
  4. Flush all soil/foul pipework with clean water.
  5. Check the cold water storage tanks /mains fed Calorifiers for correct filling.
  6. Flush the Calorifiers and hot water systems and bleed out any air.
  7. Bring hot water up to 60oC and pasteurise the hot water services and outlets, flush through. Cold water services should be flushed through with fresh water for at least 2 minutes at each outlet. Consider chemically sterilising the system, dosing the incoming main, cold water storage tanks and Calorifiers, drawing the chemical through all outlets, dependent on the age and condition of the systems and the occupants of the building.
  8. Check flow and return temperatures on Calorifiers or water heaters to make sure they conform to standards. (60oC on the flow and a minimum of 50oC or 55o in healthcare on the return, if return fitted).
  9. Re-calibrate all TMV’s to a maximum outlet temperature of 43oC (if installed).
  10. Remove any warning notices.
  11. Take a bacteriological sample from several outlets on the system to confirm that the flushing or disinfection process has been successful.
  12. Issue works report, disinfection certificates and sample analysis (if appropriate) report to the client for filing in the site log book.
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