Central heating Problem when adding a new radiator..

[ROTUNNO]

Hi all,

I have Vaillant 831 HE combi

The radaitors are set up where the flow and return pipes are on the left, bottom side of the rad with a 15mm pipe going to the top of the rad where the TRV is.

I have replaced one with a fancy rad and changed the pipe work so that the feed with the TRV goes in the bottom left and the the return, with lock shield on the bottom right.

The problem I have.. is that the new rad gets roasting hot, the other 2.4m x 600 mm h rad (double con), downstairs, stays cold, though the feed and return pipes are hot.

And the upstairs rads take ages to get hot.

I have drained and bled the system twice. When I turn the lockshield off for the new rad, it turns the upstairs rads off.

Any takers?

House is late 70's, used to have a gravity feed system before chaging to combi approx 2 years ago.

Regards

Steve

 

[gas4you]

What happens if you turn this hot new rad off?

Is your system an old single pipe system or modern standard twin pipe?

 

[ROTUNNO]

When I turned the new rad off... the upstairs rads seemed to cool.

I don't know if it is a single flow system, though the house is late 70's and was on a gravity fed system. Prior to the gravity fed system the hot water was controlled by a tower block near by.

Its a bit strange as I have taken off 3 rads for decorating - no probs.
I have changed a normal rad for a towel warmer in the bathroom - no probs.

When I came home today, again the new rad was roasting. I turned off the system, bled it and filled it up. Now nothing on the heating side works!

And its freezing tonight! Should have sorted this out in the summer when my mrs told me too!

 

[ROTUNNO]

Sorted!!! It took 10 Evenings! I whittled the problems down to a blockage. So I isolated each radiator on my single pipe system, then flushed each one.