Help - New Rads Wont Heat - Kids Not Happy‍♂️

[Dave Smig]

Hi gang, New extension built, one 1 radiator removed, 2 New ones added, another radiator moved position. The main house still heats up fine, the 2 New ones won't get hotter than low luke warm and the repositioned one now only gets quite warm. The main house in 15mm copper pipe. All pipework to New and replaced is 10mm white flexible stuff. Could the lack of warmth to new stuff be due to 10mm new pipe? Builder blaming my boiler but it works fine on main house. Even when new is isolated from main house it still won't get hot. Kids devastated... Could it be my boiler or the new pipes etc? Cheers all

 

[gas112]

might just be an air lock turn every rad off apart from 1 of the new ones and force the heat through then turn that one off and turn other new one on force heat through to that then do it to repositioned one then leave those 3 on for about 20 minutes before turning the rest back on

 

[Justin Passing]

It's a "balancing" difficulty even with no airlock.
The lockshield valves on the rads nearest the pump should be only a tiny bit open, maybe 1/8th of a turn or less if it's very close to the pump.
The smaller each rad, the less it needs to be open.
Sketch out the actual lengths of pipe and it'll become clear where the resistances are.
If you have a rad across where the two pipes go to the extension, start with it shut because it'll "short circuit" the extension.. Valves have resistance, then pipes - rads don't!
I don't know if new pipes have bubbles clinging to their insides for a while, restricting the flow, but it seems that way.

I have a flat where I had top glue one bathroom valve. She'd kept opening both valves and the rest of the place went cold.

 

[Dave Smig]

Thanks so much for this JP... I will take some time to fully absorb and understand what you mean so I can give this a good shot! I appreciate you taking the time out.

 

[Dave Smig]

might just be an air lock turn every rad off apart from 1 of the new ones and force the heat through then turn that one off and turn other new one on force heat through to that then do it to repositioned one then leave those 3 on for about 20 minutes before turning the rest back on

Thanks Gas 112. I have tried turning all off apart from the 2 new. Pipes inlets at base of rads is red hot but the new never get much hotter than just above luke warm. I've even shut off all rads except just one new and it still only gets slightly warmer. Really frustrating

 

[Deleted member 294929]

If you 10mm pipes feeding a radiator then they need to be teed off a 22mm pipe. Ideally copper.

 

[Deleted member 294929]

Is it a designer radiator?

 

[Dave Smig]

Just to add, over the weeks as I've tinkered as a home DIY'er, after fully bleeding the system, tweeking pressure etc, I now have the 2 new rads fully closed as they don't work anyway but all others rads opened as full as possible both valves sides of each rad. I suppose that's not helping 'balancing' now is it? thanks again all.

 

[Dave Smig]

Is it a designer radiator?

Hi, sort of, tall thin radiators, thanks

 

[Deleted member 294929]

Hi, sort of, tall thin radiators, thanks

Sometimes these radiators are directional. It may be the the flow & return pips are the wrong way round

 

[Dave Smig]

Sometimes these radiators are directional. It may be the the flow & return pips are the wrong way round

Thanks another one for me to look onto

 

[Deleted member 294929]

There may be a sticker on the back

 

[fillyboy]

Sometimes these radiators are directional. It may be the the flow & return pips are the wrong way round

When I knocked through my dining room kitchen, we bought a tall tower rad, which I hung myself to save the plumber time, after he ran the pipes and connected them, he fired up the system and we found only the bottom of the rad was hot. He checked a few markings on the rad and told me I was a c**t, the rad was upside down, there are baffles at the bottom of the rad to deflect the inward flow upwards.
I've no idea what the markings are but that would be my first line of enquiry.

 

[RandomGrinch]

Hi, sort of, tall thin radiators, thanks

I have one of those, and can confirm it has got baffles on the bottom.
It could very well be upside down!

A relatively straight forward check - (with all valves closed) undo and remove the bleed valve and blank plug on top of the rad and shine a light through - if you can see through to the other side, it is the right way up. If you can see something like an angled penny washer inside, then it is upside down!

 

[fillyboy]

I have one of those, and can confirm it has got baffles on the bottom.
It could very well be upside down!

A relatively straight forward check - (with all valves closed) undo and remove the bleed valve and blank plug on top of the rad and shine a light through - if you can see through to the other side, it is the right way up. If you can see something like an angled penny washer inside, then it is upside down!

I'm 100% certain that's the issue. Top marks to Bod. Correct diagnosis.