Laddomat pipe design

[mousebndr]

Got my new laddomat 21 the other day, and flicking through its manual I came across its recommended piping design - very different to what I had been planning based on TARM designs.

Basically they say having the return line from the radiators connecting to the return line to the boiler causes the water from the boiler to get too hot and thus reduce the potential of the storage tank (boiler cuts back). Seems like they are suggesting by returning the radiators to the storage tank you increase the DeltaT in the boiler, thus driving more heat into storage. I guess that aids thermosyphon as well.

They also say to add a radiator bypass line from the boiler output straight into the radiator lines, to be (automatically) enabled when the storage is cold and you need heat in the house. I reckon I can just flip a ball valve when I am firing the system cold and then flick it off when the storage is up to temp.

What does everything think? I have added two pipe designs - my original plan which is a modified version of the TARM designs and one adapted from the laddomat design.

Has anyone tried one or the other and loved or hated it?

 

[PassionForFire&Water]

What's the purpose of the Laddomat21 in the 2nd schematic? There is no bypass connection on the Laddomat21.

 

[Tennman]

ditto what Passion said. So then at that point when the hot supply to the Laddo is added aren't both schematics the same? The Laddo automatically manages the bypass for you which (unless there's something I don't know which is ENTIRELY possible) you need to add that red vertical line to the lower schematic. I've also read on here the need to place the expansion tank near the large circ pump to reduce pump noise. Hopefully others more knowledgeable will chime in if where you have your expansion tank is a good choice. I'm relocating mine to hopefully reduce the noise from my Taco 0013 (pretty big pump). I'm following your schematic since I intend to replace my Danfoss with a Laddo 21-100.

 

[mousebndr]

Whoops! Sorry forgot that line - diagram updated.

I guess the big difference between the two is that in the first diagram the radiator lines are tee'd off the supply and return lines between the storage and the boiler where as the laddomat design insists that you should not have them linked at all and they should be plumbed into the storage tank separately.