Gravity hot water problem

[Teggs]

Guys,

I recently changed a valve on a radiator at my mothers house. She has a Potterton Kingfisher floorstanding boiler.

After draining the system I then fitted a TRV on the radiator, refilled the system and then turned it all back on. Everything was fine until I noticed that the radiator didn't get warm and I didn't have any hot water. All other radiators are hot.

I took up a floorboard by the cold radiator and found that this was plumbed into the hot water pipes (and is gravity fed). I have tried all sorts to get heat into the pipes but have got no where. This included:

* Taking off the radiator and opening the valaves to flush out the pipework
* Draing water from the gravity pipework downstairs (the draincock is connected to the gravity return pipework)

I have noticed that the cold radiator needs bleeding regularly, but even when this is done no heat is experiencede.

I have double checked the instructions and can not work out what may be the problem. Is it possible that there is an airlock in the pipework? There are no zone valves so fitting the TRV (according to the instructions) was fine.

Any help would be appreciated.

Terry

 

[ChrisR]

check the holes into the rad are both clear - one poster found that his ptfe stretched across blocking it. Goo can do it too.
Yes it could be an air lock. Hard to get rid of on gravity rad circuits. Better if the feed to the rad goes in at the top.

 

[PEDANTICVINDICTIVEMAN]

Yea caught me out using a cheap rad BOE only, had to change it for a TBOE rad, ran flow pipe to top and all fine.