Magnetic Filters...and what they do...


In most heating systems the water becomes black over time, the black in the water is actually a form of rust. 


The black (rust) is created for a number of reasons, the 2 major ones are:

  1. Lack of inhibitor chemicals in the central heating water 
  2. Oxygen getting into the system 


The rust comes from your iron or steel radiators corroding over time. Occasionally a radiator can start leaking because it has rusted away from the inside but the more common problems are associated with the rust forming a sludge which can block the radiators and pipes and when it enters the boiler it forms a hard scale in the hottest and most turbulent areas (heat exchangers and pumps).


The magnetic filter has a strong magnet that the water flows over and around, any magnetic particles are trapped and prevented from re entering the system. 

The magnetic filter should be fitted on the return pipe to the boiler in an easily accessed location so it can be cleaned easily. 


Most boiler manufacturers require that a magnetic filter is fitted as part of the boiler warranty. 


Fitting a magnetic filter is a great way to ensure your heating system is kept at it best but shouldn't be fitted as an alternative to having the system power flushed. 

Power flushing uses a very powerful pump to dislodge the sludge from the system, then the magnetic filter removes any remaining particles that are produced. 

The other thing to consider is that the inhibitor concentration is correct as one of the inhibitors jobs is to neutralise any oxygen in the water to prevent corrosion. 


Remember, our specialist heating engineer service across the Leeds, Bradford and Wakefield areas will cover all of the above and much more. If you need any assistance, don't hesitate to get in touch.