Can anyone tell me what this 15mm pipe is?

[mylocalplumber]

Replacing potterton suprima with 24 ri

current flow comes from boiler tees off for what must be vent then tees off to a 15mm pipe then goes to zone valves

on the return I got a 15mm pipe which must be from the header tank then the pump.

question is..what is that 15mm pipe for on the flow?

any help appreciated and thanked

mo

 

[kris]

Is it not a bypass pipe linking the two,

 

[kris]

The vent that you saw could be a combined feed and expansion pipe , does the 15mm pipe go vertical

 

[Chalked]

Probably a bypass!
but a picture speaks a thousand words.

 

[mylocalplumber]

Probably a bypass!
but a picture speaks a thousand words.

 

[mylocalplumber]

How do I add pictures? On iphone at moment so maybe that's the problem.

anyway, the 15mm pipe runs vertically downwards, goes under floor and that's as far as I can trace at present.

 

[Rybo_1]

Towel rail circuit maybe?

 

[Rickster123]

Towel rail circuit maybe?

+1. :smile:

 

[mylocalplumber]

+1. :smile:

I'm steering this way too. How can I best incorporate it on the new system. Just pipe on as it was before?

 

[Rybo_1]

Are you keeping pump on the return?

 

[mylocalplumber]

Are you keeping pump on the return?

No. Pump will be on flow to auto bypass then zones just not sure the best way to add in this pipe?

 

[Rybo_1]

If you can, then tee it in after the pump and before the zone valves

 

[mylocalplumber]

If you can, then tee it in after the pump and before the zone valves

So that'll be my bypass then? No need to add one is there?

 

[wild nomad]

If you want it as the present system, as Rybo says. It's designed to give you a warm towel rail even when the heating is off. A good way to tell for sure is to make sure all the rads are cold then turn on the hot water only. If the towel rail heats up then thats what the 15mm pipe is for.

Tee it in after the heating zone valve if you don't want this.

If it has a gate valve or auto by-pass valve then it's your heating by-pass and the other end should connect onto the other heating pipe.