Central Heating Return Pipe for Magna Clean

Evening all,

I want to install a Magna Clean onto my CH system, I am of the understanding that it needs to be installed on the return pipe. However I don't know which pipe is what in my airing cupboard and need help to identify. I am unable to install it near my boiler unfortunately due to lack of space which is a shame as I know which is the return!

In the image the red marked pipe is hot to touch and goes to the floor standing water tank and the blue marked pipe is cooler. The other 22mm pipes have an isolation valve on each of them and no idea what they are but both are cold.

Any help would be appreciated.

The ideal place for the filter will be the primary return, as you know. If you follow the cooler pipe that comes out of the cylinder coil, that is a return, but it would be better to find where that joins to the central heating return - they will usually connect together at some point before the boiler and put your filter between that tee joint and the boiler. In practice, if your boiler is ground floor and your airing cupboard is not, you may find this section of pipe is under the floorboards and you'd need to modify the pipework if you intend to have the filter above the floor surface.

Sometimes it will be possible to put the filter on the flow, which will help keep the system clean but not be so effective at protecting the boiler itself, if you aren't up for modifications.