Radiator not getting warm - at all!

As part of a revamp to the downstairs cloakroom I re-routed the radiator pipes up and over the doorway (meant I had a clean wall for the shower cubicle). So they now do an inverted "U". Since doing that the radiator has not got warm when the system is on, all others are OK. They have been bled (many times and the valves are open). If I remove a bleed screw, eventually warm water will come out - so the feed is OK. I have fitted an automatic bleed as high as I can up the wall on the return pipe, that has had no effect.
Do I just accept that the additional pipe run up and over the room (approximately 9m out [3m up, 3m across and 3m down] out and back) is now just too much for my pump and simply fit a more powerful central heating pump?
Anything else I can try first?
Cheers
Peter
Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
puffernutter wrote:

has been dislodged and blocked a pipe. I don't like the sound of "eventually warm water will come out" Does it still only creep out when the pump is off? Shut the other valves off and force so flow through the errant radiator.
Bob
Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Dec 1, 12:06 pm, Bob Minchin

Bob,
Thanks for the reply. Poor choice of words! It comes out after being cold for a while - it is furtherest from the heat source. Pressure is good. I have tried turning all the others off, but with no luck - it remained cold.
Cheers
Peter
Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
puffernutter wrote:

Bob
Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 01/12/2011 10:44, puffernutter wrote:

> Turn off all the other rads and run the system for a while. Hopefully this will push the airlock through to the cold rad. You should hear gurgling in the cold rad. Keep checking for air in that rad. If successful, turn all the others back on and all should be well. If that fails, there are other methods to try, but are a bit more drastic. It is almost certainly an airlock. Once cleared, the pump should easily cope with it.
--
Bod

Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 02/12/2011 09:16, Bod wrote:

Shut everything else down and left it running. No change! Still cold.
Drastic measures.....? What are they then?
Cheers
Peter
Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 02/12/2011 22:08, puffernutter wrote:

> The guaranteed method to clear the airlock would be to connect a hosepipe from the water mains and blow the airlock back through the system from the offending rad, but it's not easy to do and would need two people. One to turn the hose on and off when necessary and the other on the rad. Best left to a plumber though. Not recommended on a combi boiler though.
--
Bod

Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.