identifying connection on new Cylinder

[PDrawmer]

I've got a new twin coil cyclinder for a solar installation.

In between the connections for the boiler, there's a female threaded boss into the tank. It looks about 18mm.

What's it for?

The boiler connections are in the middle of the tank which is 1800 tall. The solar connections are at the bottom, with the cold feed just below the solar return.

 

[ChrisR]

Sounds a bit low, but could be for Secondary circulation return?
Tried the mfrs websites?

 

[ajstoneservices]

It maybe a sensor pocket what make of cylinder is it.

 

[PDrawmer]

Thanks for the suggestions.

it's a Newark Cylinder - there's no mention of it on their website, or on the tank certification stickers.

It does have two 10(?)mm sensor pockets for push in sensors.

But this is much bigger, threaded and an opening into the tank.

 

[namsag]

As chrisr says or a shower supply outlet . Just make a bit up to plug it off

 

[ajstoneservices]

It is probably a secondary return fitted as standard on large Newark cylinders, ring Mark at Newark to confirm that, the numbers on their web site..