help! cold rads after partial drain

[danlightbulb]

Hi all,

I today removed a radiator downstairs to decorate behind it. Upon trying to remove the rad the union nuts were on really tight and i damaged the 15mm feed.

So in order to replace this I had to drain down this part. I closed header tank feed, attached a hose to the drain point and let it drain down.

Replaced pipe, did decorating, refitted rad, reopened header tank feeder and refilled all ok.

Bled all rads throughout house, water getting to top of all of them.

Turned on central heating - only 2 closest to pump (upstairs) are getting hot (these ones are always the hotest). Others stone cold.

I can hear gurgling sounds and I also heard a loud whistle, which I believe to be an aire release point near the pump (it has a screwdriver adustment on it). I attempted to bleed pump but the bleed screw was nearly all the way out and I could hear no hissing. Only a trickle of water was coming out.

It was all working ok before I started messing so its got be something ive done. Like I said I can hear gurgling but don't know what to do I've bled everything I can see to bleed.

Help really appreciated in this freezing weather!

Thanks
Dan

 

[bones001]

try turning the two that are working off also there will be a gate valve on a 15mm pipe that is between the pump and the 3 port valve, this is a bypass valve shut it completly and this should force more water round check your pump is on speed 3. if it works open the bypass again but only two turns.

 

[Gary_M]

If it's a 'closed system', you'll probably need to re-pressurize it again.

If this is the case, you should find some 'taps' allowing you to add more water into the system.

In my case, they are in the attic, beside the pressure guage, and it runs at 1.1bar.

Good luck,

Gary

 

[bones001]

also if the cylinder is unvented you may find an air vent right on the top of it.

 

[danlightbulb]

Thanks all,

Gary - its an open system so no pressurising necessary.

Bones - its an old system so no 3 port valve. I have a manual valve that isolates central heating, I closed this and there was an increased gurgling sound - what do I do next?

 

[bones001]

its probably airlocked, open that valve again, try turning all rads off and opening one at a time to force the air through

 

[danlightbulb]

I'll try that thanks for suggestion.

When I open the pump bleed valve nothing comes out, not even water? Is this right?

 

[JPC]

have ur rads downstairs got drain valves ?
if closing all but one rad does not shift the air then try turning boiler off open down stairs drain valve and allow to run for 10 secs ? 20 secs ?
u should hear aload of air moving about - this should help dislodge an air lock