(800) 543-5975

Boiler Plumbing


The RHO-MAG™ power flush filter has been developed as a complementary accessory to the RHO-FLUSH™ 1000.

Power flushing is the fastest and most effective means of cleansing sludge and corrosion debris from central heating systems. The process utilizes a high flow of water to loosen and ultimately expel the debris, usually containing large quantities of black iron oxide, from the system. The RHO-FLUSH 1000 is used for this purpose (for further information see: RHO-FLUSH 1000).

The RHO-MAG power flush filter has been developed as a complementary accessory to the RHO-FLUSH 1000 power flushing pump to quickly remove circulating magnetic debris from the flushing water, using the power of a rare earth magnet to attract magnetic iron oxides away from the water flow.

The RHO-MAG filter is installed in line with the RHO-FLUSH 1000 power flushing pump. The cyclone construction directs contaminated water through a powerful magnetic field, retaining even the smallest of magnetic particles on the center of the magnet, from which they may be easily cleaned during and/or after power flushing. Collected magnetic debris, which may otherwise lead to blockages in small bore pipework, is prevented from re-entering the heating system. The rapid removal of debris from the flushing water prevents saturation of the cleaning solution with sludge, leading to a more effective power flushing process.

Benefits of using the RHO-MAG alongside the RHO-FLUSH 1000

  • Increases power flushing efficiency.
  • Reduces time taken to power flush a system.
  • Prevents re-circulation of debris through the boiler or hydronic system.
  • Minimizes water consumption during power flushing.
  • Reduces black iron oxide discharge into the sewer system.
  • Transparent cylinder gives visible indication of the need to clean magnet.
  • By-pass enables filter to be cleaned without interrupting power flush process.
  • Supplied in protective tool case.

Overall: The time savings on every job when using the RHO-MAG power flush filter will rapidly cover its cost, reducing the job time and consequent disruption for householders.

Instructions for use

The power flushing pump can circulate the system water in either direction by operation of the flow reversing lever. However we suggest that the initial set-up is such that the RHO-MAG filter is installed before the boiler to offer the boiler a higher level of protection in the early stages of the power flush.

  1. Place the RHO-MAG power flushing filter adjacent to the power flushing pump on a suitable drip tray.
  2. Select the required direction of flow and position the pump flow reverser lever in that direction.
  3. Install the filter on the flow from the flushing pump using the short (59”) hose supplied. Connect the flow to the bottom connection on the filter.
  4. Using the power flushing pump standard flow and return hoses connect both the pump and the top connection on the RHO-MAG to the heating system.
  5. The RHO-MAG three-port valves should be in the CIRCULATE position.

Operating instructions

  1. Turn on the power flushing pump. Ensure there are no leaks on all connections and the top of the RHO-MAG cylinder.
  2. After initial circulation for approximately ten minutes, turn the three-port valves 180° into the BYPASS position.
  3. Remove the securing ring from the top of the cylinder and carefully lift out the magnet while gripping the handle firmly.
    Note: the magnet is very powerful and is strongly attracted to steel surfaces. Take care not to trap fingers and avoid contact with sensitive equipment.
  4. Inspect the magnet for collected deposits and, if necessary, clean as follows:
  5. Grip the cylinder lid and handle with one hand. Whilst wearing disposable gloves, grip and slide the magnetite sludge down and off the magnet.
    Note: It is advisable to only remove a proportion of the deposits with each stroke, starting at the lower end of the magnet, rather than all at the same time. Clean the end of the magnet.
  6. Collect the sludge in a suitable container for later disposal.
  7. Re-assemble the RHO-MAG ensuring that the magnet locates within the circular recess at the base of the cylinder, and turn both three-port valves back into the CIRCULATE position.
  8. Repeat the inspection and cleaning procedure as required during the flushing process.

Cleaning the magnet

It is not necessary to remove all deposits during the intermediate cleans while power flushing. However, to ensure a long life, the magnet should be thoroughly cleaned and dried at the end of each job.


The RHO-MAG contains a strong magnet and generates a very powerful magnetic field. When removed from the cylinder, keep away from electronic equipment, watches, mobile phones, credit cards etc.

Technical data
Strength of magnet:
11,000 gauss
Overall height:
Length of magnet:
Overall width:
Magnet surface area:
5.16 in2
Overall depth:
Weight of unit:
10.9 lbs

Related Products

RhoPure 300 & 1000

RhoPure™ disposable cartridges contain a demineralizing filter media. They are ideal for demineralizing fill or make up water for hydronic systems. The quality of water, especially when required to be mixed with glycol, can have an impact on system performance.



The RHO-HAMMER™ has been developed to flush out corrosion and sludge that can build up in heating systems.


Rho-Flush 1000

Power Flushing Machine Premium power flushing machine with the performance and versatility to handle all your power flushing…