Low loss header query

[Paul - PDS]

HI all, I am working out the best way to install a Worcester 42 CDi into a 2 zone system.

We currently have 2 pumps and 2 2port valves but the just on return back into boiler room.

I will be putting in a LLH so the pumps don't intervene with the boiler pump - Is there anything wrong with just having a single return? I was just going to cap off the extra tail on the LLH? I can't see why It wont work but would like a second opinion! Please see my fantastic drawing of what im going on about

Thanks

 

[Gray0689]

What are the 2 zones do you really need 2 pumps and 2 zone valves

 

[EPH]

Why do you need a LLH with one boiler?

You only need 2 zone valves and a bypass.

 

[happyflyer]

Don't put the F&R pipes facing each other on the LLH like you have shown, stagger them, the boiler F&R at each end of the header and the other side
a little way in. I love the LLH systems even though you may not need it it does make sure you have full flow through the boiler at all times.

Sign of a good job a LLH, but what would I know about all this. Nothing wrong with the two ports, makes sure no heating creep which can happen through and idle pump, needs
a bit of fancy wiring, is there a shunt pump in the boiler???

Baldy old git!

 

[Ermintrude]

I would go with shunt off the boiler PCb connections so overrun is good.

Assume that your return is somewhere over the rainbow that's why u only have common return.

Two ports are recommended by WB on their TB14 it makes s/l easier to isolate for two zones.

Malaise ur system connections right size! 35mm to LLH and probably 28mm to zones. Don't fit 22mm zv as you may aswell remove LLH and just fit a 24kw heatline.

ALSO A COMBI? Are you having metal health issues? 40cdi regular. Don't fit the system boiler they are cacckapoo!

 

[chris watkins]

Why a common return back to the header, just can't get them back to the header??

It would all depend on the pipe sizing & the water flow as each pump / zone opens & closes it would effect the common return connection point.

Why not have a single pump on a common flow with each circuit zoned at least then the pump will adjust its speed to adapt to the zones opening & closing ?

 

[Ermintrude]

Nice was thinking same make it a common flow split returns.... But if no access is it 22mm? For 40kw of ch???

 

[happyflyer]

Don't common the returns and spoil the job, bring them both back to the LLH, see Emi drawing, it just like he did in his house, gauges, NRV, AAV, the Jewson Lot

 

[Paul - PDS]

Thanks a lot for the input much appreciated! The exsiting system is running 2 pumps and IMO the circulation isn't brilliant, not sure that the 42cdi pump alone would be up to the job. The reason I'm putting a LLH in is so the pumps aren't working against eachother - regards to the overrun, won't the boiler pumping through the LLH be ok when zones are switched off?

 

[EPH]

How bigs this property then? I don't know how many times I've spoken to their technical and they've insisted the pump on the system boiler will manage if the boilers the right size.

 

[Ermintrude]

Baldy mines got 7 two ports and a 22manifold and 6m pump in boiler

 

[EPH]

Baldy mines got 7 two ports and a 22manifold and 6m pump in boiler

Less of the insults you!!

 

[Ermintrude]

Less of the insults you!!

Was aimed at happy flyer. U a shiny top ?

 

[happyflyer]

Baldy mines got 7 two ports and a 22manifold and 6m pump in boiler

And a partridge in a pear tree, Merry Christmas and a warm one Ermi :santa3::santa3::santa3::santa3:

 

[happyflyer]

Thanks a lot for the input much appreciated! The exsiting system is running 2 pumps and IMO the circulation isn't brilliant, not sure that the 42cdi pump alone would be up to the job. The reason I'm putting a LLH in is so the pumps aren't working against eachother - regards to the overrun, won't the boiler pumping through the LLH be ok when zones are switched off?

If you are in any doubt go with the force Obi-Wan, don't go over to the dark-side, use the LLH and fit a proper job, never rely on the poxy pump the manufacture fits in the boiler case its the bare minimum they don't give money away get smart. :45: