Pipe diameters challenge

[Vee]

Upgrading the pump could be an option instead of increasing pipe sizes.....

 

[doitmyself]

Which boiler do you have (make and model no); and how old is it?

 

[Sparkgap]

Hi,
Thanks for response.

The plastic pipe has a internal bore of 13mm. At present the manifold is fed by 22mm from storage tank but the intention is to bypass the storage tank and connect the boiler straight to the radiator manifold and underfloor manifold to give instant heat from the oil boiler instead of drawing heat from the heat exchangers in the storage tank.

I do have a picture of current configuration but do not know how to put a picture on the thread.

I am willing to increase the diameter of pipes from manifold but this will cost circa 1k and when doing the maths of flow vs velocity I am struggling to see benefit of bigger pipes.

Boiler is 22.5kw oil fired.

Sorry if my questions are stupid but I am trying not to spend 1k if I do not need to.

Cheers

Dickspanner

From the description it sounds like you've got the boiler running into a buffer tank then a heating circuit from the tank to the manifold. For the rating of the boiler and assuming 20C temperature difference on the system you can get away with 22mm but the resistance is quite high and if you're using the same pump to circulate through the boiler and the rads you'd need to check you're getting the correct flow rates. Another issue would be what happens when one or more rads shut down. Do you have a bypass valve on the system to keep the flow up through the boiler?