Rad slow to heat up fully

[ZakUK]

Got extension built and new verical radiator installed (Brenton flat double panel 1800 x 600). The TRV is bottom right, lockshield - bottom left. When heating up, top right starts to feel warm, bottom left still cold. Later on, top right is very very hot, while bottom right not cold, but luke warm. Did bleeding, water out straight away. Water is clear.
No problems with the rest of radiators in the house. They get hot fully and quite quick.
Any ideas ?
Thx !

 

[Madrab]

Any ideas

Yep - they're crap - don't heat the space very well - and need and adequate system flow to work properly.

If it's in an extension then it may be it's been spliced into the CH system as the farthest rad and/or connected to the feeds for another rad so is running off a 15mm pipe and not getting the flow it needs.

Has it always been like that? Total number of rads?

 

[ianmcd]

Some vertical rads have a baffle and the flow must go into the baffle side or you will get the symptoms you describe

 

[ZakUK]

Yep - they're crap - don't heat the space very well - and need and adequate system flow to work properly.

If it's in an extension then it may be it's been spliced into the CH system as the farthest rad and/or connected to the feeds for another rad so is running off a 15mm pipe and not getting the flow it needs.

Has it always been like that? Total number of rads?

Vertical crap or that make crap ?
Builder drilled 2 holes in the wall to connect and it is the furthest one in the system.
Its been like that since it got installed 2 weeks ago.
Total 7 rads in the house including this one.
Is there a solution ?

 

[ZakUK]

Some vertical rads have a baffle and the flow must go into the baffle side or you will get the symptoms you describe

Baffle ?
Just see 2 valves on the rad ...

 

[Chivas69]

How long did you bleed it for? It sometimes takes a few seconds for air to splutter out.

 

[ZakUK]

How long did you bleed it for? It sometimes takes a few seconds for air to splutter out.

There was no air. Opened and water out straight away.

 

[ianmcd]

Baffle ?
Just see 2 valves on the rad ...

The baffle is inside the rad, do you know the make and model of the rad ? which pipe gets hot first left or right side ?

 

[ZakUK]

The baffle is inside the rad, do you know the make and model of the rad ? which pipe gets hot first left or right side ?

Brenton flat double panel 1800 x 600 (https://www.onlyradiators.co.uk/p/brenton-double-vertical-flat-radiator-1800x590-pv).
Right pipe (TRV) gets hot first

 

[Chivas69]

There was no air. Opened and water out straight away.

Yes but that doesn't necessarily mean it is free of trapped air. Often you will get instant water then all of a sudden, big splutters of air as it's pushed through (trapped other side of rad, trapped in pipes, trapped in other radiators)

 

[Madrab]

Vertical crap or that make crap ?

Apols - vertical designed column rads are generally rubbish at heating anything but the smaller of spaces properly, it just the way they are designed, unless there are a number of them and they are all relatively large, they can also be difficult to heat properly if they aren't supplied properly (probably your issue)

When heating up, top right starts to feel warm, bottom left still cold. Later on, top right is very very hot, while bottom right not cold, but luke warm.

If the heat rises up the first column or 2 and they warm up and that then permeates down the other columns then that indicates that there probably is a baffle but if the whole rad isn't heating properly then chances are there isn't enough supply to satisfy it.

Has it always been like that? If it's been fed off of the same 15mm pipe as another radiator, does that radiator heat up ok? If so, is the column just on the other side of the wall? If so then you may need to throttle the normal radiator down a bit to shift some more flow towards the column rad.
TBH though, the installer should have done all of that and set it up properly.

 

[Madrab]

trapped other side of rad, trapped in pipes, trapped in other radiators

???

Air will always travel to the highest point it first comes across, if there's air in the column then that will travel to the top of it and be expelled through the vent mostly all at the same time, same with any air in the pipes. Air that is in other rads will sit in the top of that rad to be bled by that's rad's own vent. All the air in the system won't all be bled by this single column rad, if I read that correctly.

 

[oilhead]

Close the flow valve and bleed again, releasing a couple of litres of water. You may find an airlock on the return and bleeding with both valves open will not releive this.

 

[Chivas69]

I meant air can be blocked somewhere in the system and it may need more than a quick bleed to shift it along. Air will get to the highest point but it isn't always instantly. Bleeding for more than a quick 'yep, there's water there' will often help with getting any trapped air moving along, past sludge and debris.

 

[ZakUK]

Apols - vertical designed column rads are generally rubbish at heating anything but the smaller of spaces properly, it just the way they are designed, unless there are a number of them and they are all relatively large, they can also be difficult to heat properly if they aren't supplied properly (probably your issue)


If the heat rises up the first column or 2 and they warm up and that then permeates down the other columns then that indicates that there probably is a baffle but if the whole rad isn't heating properly then chances are there isn't enough supply to satisfy it.

Has it always been like that? If it's been fed off of the same 15mm pipe as another radiator, does that radiator heat up ok? If so, is the column just on the other side of the wall? If so then you may need to throttle the normal radiator down a bit to shift some more flow towards the column rad.
TBH though, the installer should have done all of that and set it up properly.

Its been like that since the installation 2 weeks ago.
The other radiator is across the room on the other side (in other room) and it heats up quickly and very well.
Throttle the radiator ? You mean closing lockshield a bit ?