New Radiator only gets hot working on its own...help please

[Needy]

Hi All

Recently plumbed in a new Radiator in our Conservatory as just 1 wasn't enough so now have 2 , So in that area including the kitchen we have a total of 4 radiators

The new radiator will only get hot if i shut off the other 3 Radiators off , when the 3 are turned back on the new Radiator goes cold

Can someone point me in the right direction why this is happening please

Thanks

 

[terryplumb]

Do you have zonal heating ?
Where did you connect the new rads pipework to ?
Did you balance the system after adding the new rad ?

 

[Johntheo5]

If you shut off the old conservatory rad do the remaining 3 including the new one get hot?.

Is the new rad the same size as the other conservatory one and what output or size?.

If the two conservatory rads are column type there may be be a arrow showing the flow, new one may not be installed properly.

 

[kidgreen61]

You have proved (by turning off other rads) that you either have a balancing issue, as said above, or the pipework is too small to accommodate extra rad.

 

[Bod ...]

Have you teed into 10mm micropore?

 

[Johntheo5]

3 old rads circulated OK but not sure if OP has tried it with the old towel rad off, if still no circulation through the new rad then problem with this rad even though it does circulate on its own?