radiator balancing ??

[gazmacker]

hiya lads , went to a job to remove old rad and fit a new one in its place but for the life of me i cant get it to stay hot , all other rads around the house are red hot but this one situated in the front living room gets hot if i draw the water through from the drain valve but wont stay hot ?? not sure which valves are the lockshield as there are no caps on them , any help appreciated gaz , sorry i forgot to mention its a gravity fed system cheers

 

[helpsy]

Try shutting down all the rads except the problem rad, and bleed air out , if not may need balancing.

 

[gazmacker]

cheers helpsy for the info , when i left the house it was hot but its like its just not circulating . how can you tell which side is the lockshield on the existing rads as the valves all look the same and there are no white caps on them ? this is a really old system and have never come across this prob before ?

 

[PlumbBobBob]

doesn't really matter which side is lockshield shutting either off will stop flow through rad.

 

[fuzzy]

are both valave open? sounds silly but the prob is it isnt circulating, if it aint circulating it wont stay how.
if they r both open then yes try shutting down other rads to force heat through, if it still aint warm its another problem, let us know how you go on mate