Upright Rads not heating up for long

[gasbusters]

Hello all. I have a bit of a dilemma.

I recently completed my loft extension and I'd fitted 3 upright radiators up there. These ones

1780 x 280mm Anthracite Double Flat Panel Vertical Radiator

1780 x 280mm Anthracite Double Flat Panel Vertical Radiator

Add warmth to your home with our designer 1780 x 280mm double flat anthracite vertical panel radiators. Adding a designer feel to your home at affordable prices.

www.radiatoroutlet.co.uk

The radiators do not get hot apart from when the system is drained and refilled.

When the system is drained and refilled, the radiators get very hot for about 1 day, but then after that they only get hot along the bottom bar, but the rest of the radiator doesn't heat up.

I've balanced the entire system. Same problem. I've even turned off all the other radiators around the house, when I do this they get hot but again only for a few hours.

I've even switched over the flow and return pipes as they enter the loft but again same problem, the radiators do not get hot for long.

I've contacted Radiator Outlet who I brought them from but again not really much help.

There's no indicator on the radiator to say which way is up and which way is down. Could these have been installed upside down?

 

[Exedon]

Some designer rads have a baffle in bottom run so possible to fix upside down (I've seen it)
Are you certain when they stop working they are not just full of air?
That type of rad often come supplied with a aladdin type air vent.

 

[Bod ...]

These sort of rads I've found hold onto alot of the swarf from manufacturing.

The flow ports on the tubes I don't believe are free of burrs and that hinders flow and catches system debris...

What I have done in the past is turn off all other Radiators.
Once I have a flow I use a Mallet or the butt of a hammer and give the ends of each individual tube (ports) a good tap. In order of flow.

 

[RandomGrinch]

I may be wrong, but I believe RadiatorOutlet and BestHeating use the same OEM - interestingly, the guide for installing the BestHeating Milano suggests:

So, baffles are recommended, but may not be installed!

 

[gasbusters]

Some designer rads have a baffle in bottom run so possible to fix upside down (I've seen it)
Are you certain when they stop working they are not just full of air?
That type of rad often come supplied with a aladdin type air vent.

I've fit aladdin auto vents to both radiators, there's no air in the system

 

[Madrab]

If you turn off the other rads and these warm up properly then it seems there's nothing wrong with the way they are piped.

Is your loft the '3rd' floor? If so then you are probably right at the circulating limit of the pump, if the boiler is on the Ground floor. As the other rads in the house are all below those columns then there may not be the headroom left in the pump to provide enough circulation to supply every rad. Adding these columns, especially given their height and the way they need to circulate the flow to work correctly (up to the top to drop) may be asking too much for the pump to handle, more so if the system is convoluted with lots of bends, longer pipe runs, pipe size reductions, etc.

Unfortunately it's not just a case of banging on a few more rads and hoping they will work.

I really hate these types of 'designer' rads, they cause nothing but endless problems especially when they are on the edge of the system's limits and they are really bad at heating anything but the smallest of spaces given the way they heat the space.

 

[Bod ...]

Is it a big house?

 

[gasbusters]

If you turn off the other rads and these warm up properly then it seems there's nothing wrong with the way they are piped.

Is your loft the '3rd' floor? If so then you are probably right at the circulating limit of the pump, if the boiler is on the Ground floor. As the other rads in the house are all below those columns then there may not be the headroom left in the pump to provide enough circulation to supply every rad. Adding these columns, especially given their height and the way they need to circulate the flow to work correctly (up to the top to drop) may be asking too much for the pump to handle, more so if the system is convoluted with lots of bends, longer pipe runs, pipe size reductions, etc.

Unfortunately it's not just a case of banging on a few more rads and hoping they will work.

I really hate these types of 'designer' rads, they cause nothing but endless problems especially when they are on the edge of the system's limits and they are really bad at heating anything but the smallest of spaces given the way they heat the space.

The boiler I have is a Worcester 2000, 30kw, was fitted about 2 years ago. It's fitted in the shed, about 4 meters from the house, the new rads have added about 8 meters of flow and 8 meters of return to the pipe runs.

In total went have 11 radiators in our house.

I've fit a lot of combis and have added radiators to lofts with similar pipe runs as my house but I've never had this problem before.

 

[gasbusters]

Is it a big house?

Not really, it was 3 bedrooms normal sized house, 2 lounges, small kitchen, 1 small bathroom, and the added loft extension.

11 radiators in total. Combi is a Worcester bosch 200, 30kw

 

[Madrab]

Don't forget the extra height of the rads, that's almost another 2m of head req, so if it is the '3rd' floor then that's around 6m of vertical head required, just for them, the other rads not withstanding. These columns need their flow to run to the top of the rad and then cascade down for it to heat the rad properly.

If the other are shut down and there is enough head in the system to reach them and then with the others on, there isn't. It can't be anything else unless there is a lower rad short circuiting the flow up to the loft.

Not knowing the pump for that boiler, I would presume it would be around 6m head?

 

[gasbusters]

I believe uts a Wilo pump