back boiler problem

[nathf1980]

hi was just wondering if any one could help me out with a minor problem, i have a baxi back boiler system and one of the rads upstairs is always half cold,
i have bleed the system several times and it still does not solve the problem ,
the expansion tank in the loft is full and the ball cock working fine so am lost as to what to do next, any ideas would be gratefully recived

 

[nathf1980]

ps. forgot to say when you bleed the rad in question no water comes out its like the rad is only half full, you some times get a small hiss of air if i have't bleed it for a while but thats it.

 

[BingoBongo]

when you bleed it does air come out?

 

[nathf1980]

some times a very small amount , but just sat there for 10 min with the valve open and nothing came out

 

[thermix]

Try bleeding when the pump or heating is off, when the heating is on the air could be sucked into the system instaed of vented

 

[BingoBongo]

what speed is the pump on?

 

[bellairaphon]

u might wanna take the rad off and give it a flush through with an hosepipe

Nath

 

[nathf1980]

ok ill switch heating off and give it a try,
is the pump the one beneath the hot water tank or behind the cover on the fire ?
if it is the one behind the cover it is on leval 2 the one in the airing cuboard is not numbered there is just a large flat head screw to turn

also forgot to say when the heating is off the rad that stays half cold is luke warm not sure if this makes a difference ,

thanyou for your help by the way as you may of gatthered my plumbing knowledge is pretty crap

 

[nathf1980]

thanks guys ! im an idiot just switched the heating off bleed it again and problem solved , i only ever think about it when the heating comes on so never bleed it when the heating is off , thats todays lesson learnt ! thanks again to all of you