New downstairs rad tee'd into upstairs circuit cold

[judesudbury]

Hi guys, first post here - so hi ! I've put a radiator into a cold part of a kitchen extension and because there was no easy way to extend the downstairs circuit (without chasing out concrete, drilling through a double brick exterior wall), I tee'd into the flow and return of the upstairs circuit in the ceiling and dropped the pipes down the wall to feed the new rad. Filled the system, bled all rads, but the new rad is stone cold. I've used 15mm pipe. Grateful for any suggestions. Many thanks, Jude.

 

[seco services]

have you closed the other rads to use full flow to the cold rad ?
more likely a airlock in the dropdown pipework.

 

[judesudbury]

have you closed the other rads to use full flow to the cold rad ?
more likely a airlock in the dropdown pipework.

Hi - I shut down the last upstairs rad in the circuit, near where I've put the tees to downstairs to see if that would push water into the new rad, but all that's happened is that the flow and return pipes are cooling at that end, so water isn't circulating at all it would appear. How does an airlock occur and how do I go about clearing it?
Many thanks

 

[seco services]

airlock can occur when filling the system.
the pipework can fill from both flow/return and the air gets trapped in the middle.

try shutting all rads not just one.
water will take the shortest route if the other rads are open.

 

[judesudbury]

Well, I shut down all the upstairs rads and the new rad got nice and hot. Bled more air out of the system. However, opening the upstairs rads up - just enough to get them hot, but not all the way, causes the new rad to get cool (very luke warm now). Having uncovered some pipework, I've discovered the d/s towel rad is also on the upstairs circuit with dropped down pipework and now this is very luke warm (it used to be roasting).

Do you think doing the drops in 22mm will encourage the water to flow down more readily?

Many thanks for your help - the initial problem was certainly an airlock which has worked its way free, but I think the issue now is a design one.

Cheers,
Jude

 

[clf-gas]

Your system just needs balancing. As seco says, the water will flow through path of least resistance.

 

[judesudbury]

Your system just needs balancing. As seco says, the water will flow through path of least resistance.

Ok - will give it a go... when balancing a radiator, does it matter if you shut down the flow or return side of the rad?
Cheers,
Jude

 

[clf-gas]

Flow open and close return side.

Looking for around 12' ish differetial across rad.

 

[judesudbury]

Noticed that the bypass circuit was fully open. Shut that off and the new rad is now hot, but the towel rad a bit further along is cold. Thanks for your help folks, hopefully balancing the system will fix it.
Cheers,
Jude