Standard TRV, flow for a big radiator?

[Nigel R]

Hmmm well it's off atm, my dodgy memory is there are simply 5 speed settings and I just click through them on the display. Edit, I see now there are 3 speeds I, II and III plus 3 little charts. I lazily haven't really explored these just used I and II. It's a Magna1. 2 wires to the boiler, job done! The boiler is 40kW Worcester Bosch 8000 life.

Using the WB smart controls it's never heating all the rooms at any one time - kitchen in the morning, living room in the afternoon etc etc.

The pump has to service an annex, cellar and 3 floors so the nice man at Grundfos wasn't leaving anything to chance I think

 

[Madrab]

Have you considered a supplimentary pump? In effect creating a seperate zone and pumping it directly? Using one large pump may be difficult to balance properly over such a large footprint, especially with three pipes size steps. Does the system use a low loss header?

I'd suggest you may need to look a little at the system design layout a bit more and rejig things to suit.

 

[Nigel R]

Oh and no I haven't tried tried to measure up the rads, but they are probably more than 40kW. The old system had 2x28kW boilers, but also a huge rad in the conservatory

 

[Nigel R]

Have you considered a supplimentary pump? In effect creating a seperate zone and pumping it directly? Using one large pump may be difficult to balance properly over such a large footprint, especially with three pipes size steps. Does the system use a low loss header?

I'd suggest you may need to look a little at the system design layout a bit more and rejig things to suit.

Thanks, no tbh I haven't. It doesn't have a low loss header. I've improved the pipe layout to this new rad so I'm hoping it'll be ok. The rad itself has big waterways and I've plumbed it diagonally. But if not, yes a separate pump could be the answer, thanks for the thought.

 

[Johntheo5]

You have plumbed it TBOE, (top & bottom, opposite ends), with the hot at the top?.

 

[Nigel R]

You have plumbed it TBOE, (top & bottom, opposite ends), with the hot at the top?.

yes, this is what the manufacturer recommended. It's a horizontal rad that's basically a big tube at top and bottom, with an array of verticals between. The outgoing vertical steel ones had flat vertical channels, this one being aluminium has good size round-section vertical tubes with fins to radiate, so the resistance should be less. More or less nil in fact, once the flow has navigated the valves