METHOD STATEMENT FOR POWER FLUSHING OF EXISTING DOMESTIC CENTRAL HEATING SYSTEMS

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Power flushing using the Power Flow Flushing Machine (PFFM). Except for some boiler amendments power, flushing with the Power Flow Flushing Machine (PFFM) should be undertaken after completion of any installation or repair work.

Preliminary Checks

• Fill the PFFM system, empty all high points, pumps and radiators.
• Check closely for any possible leaks and repair as required.

System Preparation

1. Turn off all electrical controls for the plant or area being flushed and make electrically isolation of the system.
2. Note the setting of each valve before opening them, so that the system can be re-instated after flushing.
3. Open all radiator valves to their maximum setting and remove TRV (Thermostatic Radiator Valve) heads to ensure maximum flow through the valve.
4. Set diverter or zone valves to manual.
5. Anti-Gravity Valves-AGV (non-return valves) if installed should be bridged, bypassed or temporarily removed.

Set-Up and Connection of the Power Flow Flushing Machine (PFFM)

1. Always employ best practices when protecting customer’s property for wet works.
2. Connect up the ½" clear mains water inlet hose. ¾" clear dump and overflow hoses and ¾" yellow rubber flow and return hoses to the Power flow by their Cam-lock connectors. Connect the Flush buddy between the flow/return valve and the hose using the Cam-lock connectors provided. The direction of flow for the Flush buddy is not important.
3. Ensure that the isolating valves on the flow and return hoses, mains fill and dump valve are all in the closed position and that the waste hose and overflow both terminate in a foul drain.
4. Ensure that the dump hose and overflow hose both drain to a point below the dump valve on the
5. Power flow flushing unit. Failure to do so will prevent the wastewater from flowing to drain and may result in overflow of the Power flow tank. 
6. Isolate the circulator pump and, if a PFFM flow Pump Head Adapter is available, remove the pump head and connect the adapter to the in-situ pump body. Alternatively, remove the system circulator and connect the adapter elbows supplied with the Power flow unit across the power flow pump connectors. Make a Coupling to the pump head adapter, or the adapter elbows to the yellow flow/return hoses. For combination boilers where a pump head adapter is not available, connect by fitting the ¾" Power flow/return hoses directly to the main system flow and return or across a radiator. Connecting across a radiator will minimize the flow rate and may affect the efficacy of the power flush.
7. Isolate the electricity supply to the system circulator, if in doubt, seek the advice of a qualified electrician.
8. Connect the power lead on the Power flow flushing unit to the electricity supply via an RCD.

Operation of the Power Flow Flushing Machine (PFFM).

1. Turn on the mains supply and fill the vessel between the maximum and minimum marks.
2. Open the flow and return valves and allow the unit to run for 15 minutes with all radiator valves open, reversing the flow regularly.
3. Dump the dirty water to drain whilst adding clean water to the reservoir tank until the TDS of the dump water is within 20% of the incoming mains water.
4. Refill the system and add the PFFM cleaning product of choice to the Power flow Flushing Unit via the chemical addition port. Open the mains water inlet valve and fill it with water to approximately halfway between the maximum and minimum liquid level markers on the reservoir. Close the mains water inlet valve.
5. Open the system pump isolating valves and the flow/return isolating valves on the Power flow flushing unit. Ensure that the dump valve on the Power flow remains closed.
6. Switch on the machine on the power supply to the Power flow flushing unit. As necessary, control the water level in the reservoir via the use of the mains water inlet valve, ensure that the liquid level in the reservoir remains between the minimum and maximum liquid level markers.
7. Switch on the boiler and allow the central heating system to reach operating temperature.
8. Allow the unit to run for 40 -50 Minutes, reversing the flow regularly. Highlight and detect any cold spots on radiators, or blockages during this time. If the system has an indirect cylinder, make a diversion for the flow to the cylinder coil and circulate for 10-15 minutes, reversing the flow regularly. Make a diversion to the water back to the heating circuit.
9. Shut off all the radiator valves except for the radiator furthest from the Power flow flushing unit (PFFU).
10. Allow the unit to pump through this radiator for a minimum of 10 minutes or until even heat is achieved over the radiator surface. Reverse the flow regularly during this time. Tap the radiator with a rubber hammer may help to dislodge any debris.
11. Close the flow and return on the radiator and then move to the next radiator. Open the valves and repeat radiator clean. Proceed until all of the radiators have been cleaned. 
12. Draining the Power Flow Flushing Machine (PFFM).
13. Switch off the boiler.
14. If PFFM Cleaner has been used, add the PFFM System Neutralizer via the chemical addition port and circulate for a further five minutes. The system water should be green in colour. If the water is still red, further neutralizers will be required to be added.
15. Power flushing using the PFFM Power flow above) power flushing with the PFFM Power flow flushing machine should be undertaken after completion of any installation or repair work.

Preliminary Checks

1. Fill the PFFM system, empty all high points, pumps and radiators.
2. Check closely for any possible leaks and repair as required.

System Preparation

1. Make electrical isolation.
2. Note the setting of each valve before opening them, so that the system can be re-instated after flushing.
3. Open all radiator valves to their maximum setting and remove TRV (Thermostatic Radiator Valve) heads to ensure maximum flow through the valve.
4. Set diverter or zone valves to manual.

Operation of the Power Flow Flushing Machine (PFFM)

1. Turn on the mains supply and fill the vessel between the maximum and minimum marks.
2. Open the flow and return valves and allow the unit to run for 20 minutes with all radiator valves open, reversing the flow regularly.
3. Dump the dirty water to drain whilst adding clean water to the reservoir tank until the TDS (Total Dissolved Solids) of the dump water is within 20-25% of the incoming mains water.
4. Refill the system and add the PFFM cleaning product of choice to the Power flow Flushing Unit via the chemical addition port. Open the mains water inlet valve and fill it with water to approximately halfway between the maximum and minimum liquid level markers on the reservoir. Close the mains water inlet valve.
5. Open the system pump isolating valves and the flow/return isolating valves on the Power flow flushing unit. Ensure that the dump valve on the Power flow remains closed.
6. Switch on the machine on the power supply to the Power flow flushing unit.
7. As necessary, control the water level in the reservoir via the use of the mains water inlet valve, ensure that the liquid level in the reservoir remains between the minimum and maximum liquid level markers.
8. Switch on the boiler and allow the central heating system to reach operating temperature.
9. Allow the unit to run for 50 minutes, reversing the flow regularly. Highlight any cold areas/points on radiators, or blockages during this time.
10. If the system has an indirect cylinder, divert the flow to the cylinder coil and circulate for 15 minutes, reversing the flow regularly. 
11. Shut off all the radiator valves except for the radiator furthest from the Power Flow Flushing Unit (PFFU).
12. Allow the unit to pump through this radiator for a minimum of 10 minutes or until even heat is achieved over the radiator surface. Reverse the flow regularly during this time. Tap the radiator with a rubber hammer may help to dislodge any debris.
13. Close the flow and return on the radiator and then move to the next radiator. Open the valves and repeat radiator clean. Continue until all of the radiators have been completely and properly cleaned. After all the radiators have been flushed completely, open up the valves on all radiators.
14. Draining the Power Flow Flushing Machine (PFFM)
15. Switch off the boiler.
16. If PFFM Cleaners has been used, add the System Neutralizer via the chemical addition port and circulate for a further five minutes. The system water should be of colour. If the water is still red, more neutralizers are required. 
17. Open the dump valve on the Power flow flushing unit to send the water to the foul drain.
18. Open the cold-water supply to the unit and regulate to ensure the water level stays above the minimum mark. 
19. From a convenient supply point, take a sample of the mains water and measure the total dissolved solids by utilizing the Total Dissolved Solids (TDS) meter. Note the reading on the power flushing monitoring sheet.
20. Flush the system and allow the water to run to waste until it appears clean. Switch or shut off all radiator valves except for the last radiator to be cleaned appropriately, and continue flushing them with the help of the machine until the wastewater appears clean and neat.
21. Take a sample of the wastewater and measure it with the Total Dissolved Solids (TDS) meter.
22. Make a clear Comparison with the meter reading from the wastewater with the previous mains water reading. Continue flushing and sampling the wastewater until the reading obtained with the Total Dissolved Solids (TDS) meter is within 10% of the mains water sample.
23. Note the Total Dissolved Solids (TDS) reading from the radiator on the power flushing monitoring sheet.
24. When all the radiators have been cleaned, divert all the flow to the indirect cylinder coil (if present) and flush until the Total Dissolved Solids (TDS) of the dump water is within 10% of the mains
25. Open all of the radiator valves and continue to flush until the wastewater is within 10% of the mains.
26. Verify that the system has been adequately cleaned and flushed by undertaking the chloride and copper tests within the PFFM Water Test Kit.

Protecting and Re-Commissioning the System

1. After the system water has been confirmed as being within 10% of the mains, close the mains water supply and switch off the Power flow flushing unit. Close the system circulator isolation valves and disconnect the unit from the heating system. The Flush buddy can be cleaned ready for re-use, by rinsing under flowing water.
2. The system should be immediately protected by adding the PFFM Protector system. If the engineer chooses to add the PFFM Protector system via the chemical addition port of the Power flow, care must be taken to ensure that the PFFM Protector system is fully dispersed before disconnecting the machine. This will accomplish in 15-20 minutes approximately.
3. Re-connect the system circulator and restore the electrical supply to it. 
4. Install the replacement boiler if necessary. 
5. PFFM Protector system is supplied with a sticker to indicate the date of treatment and the product used. This should be accomplished and put on the boiler casing in a convenient location to allow future engineers to highlight and know the treatment regime utilized.
6. Verify Protector level is adequate using the PFFM Protector Test Kit within the PFFM Water Test Kit. 
7. Overdosing of an inhibitor will not have any adverse effects on the heating system. If necessary, add the PFFM Protector system.
8. Protector level should be checked on an annual basis. This can be undertaken as part of an annual service using either the Protector test reagent within the Water Test kit or using the laboratory postal service.
9. The valve on the Power flow flushing unit sends the water to the foul drain.

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Method Statement-power flushing of existing domestic central heating systems