2 cold rads

[justbrokeit007]

hi,
had a leak on a rad valve . drained down system partially as only needed to work on upstairs rad and replaced faulty valve. vlaves on rads are not TRV's.
filled system and bleed all rads and pump ( gravity system)
have balanced the rads but have 2 rads downstairs not getting hot.
they worked perfectly fine before.
i have bleed them again and started to get some warm water through pipes. stop bleeding and it goes cold.other rads downstairs are all working fine. water from rads in slightly dirty.
these where the rads i drained down to.

 

[Dean744PiN5]

Try turning of 1 valve on every other radiator apart from 1 that isn't working and turn the heating on. This normally gets most going within a few minutes then repeat for the other rad.
Try this first.

 

[justbrokeit007]

will try this when i get home, rads that are cold are only 1m apart as one in porch and other in downstairs cloak.

 

[justbrokeit007]

have turned off all the rads except the 2 not working ( 2 ft away from each other) no heat in rads or pipes.
suspect i have a blockage in pipes, would a couple of drain downs help ?????