Baxi Combi central heating losing pressure

[francspencer]

Hi,

Since moving into my 2 storey flat 3 years ago, I have had to top up the water using the filling loop below the boiler as the pressure has been reducing to below 0.5 bar. (I top up to 1 bar when cold)

This summer I noticed a damp patch in the wall below a lot of the central heating pipes, so I investigated below the carpet. But the floorboards are some kind of thick chipboard slabs that will be a nitemare for me to get up to investigate the source of the leak.

I have noticed the damp patch is dry to the touch but not getting any bigger, so I assume its just a small drip which is soaking into the plaster.

I have since come across Fernox F4 Heating Leak Sealer Superconcentrate,
which is for sale in screwfix. Has anyone used this into the side of a radiator? Do you simply remove the valve screw at the top of the radiator and insert the fernox pipe and squeeeze. Do the radiators need to be cold?

Thanks in advance

 

[francspencer]

anybody, please help

 

[kevplumb]

turn off both valves undo the bleed screw have a bowl / cloth handy

screw tube into bleed screw hole pump in if it gets hard to pump open a valve slightly

if opened close valve catch water with bowl

replace screw open valves

check boiler pressure