Lochinvar Noble Combi internal piping question

In_New_England

The Noble install recommends a secondary loop system for space heating (as I believe a lot of other boilers do). Water from the main heating loop is split (closely spaced tees) and there is a pump in the boiler that draws water into the heat exchanges and then returns it to the main heating loop.

For a domestic heating call, does the same, secondary loop, operate to move heat from the fire tubes to the domestic hot water heat exchanger or is there a second internal loop inside the boiler that we can't access from the outside?

Thank you.

Zman

There is an internal diverter and heat exchanger to handle DHW. Just pipe the domestic side like shown in pages 45=49 and you should be good to go. https://s3.amazonaws.com/s3.supplyhouse.com/product_files/Lochinvar-NKC110N-Install.pdf

This one shows the internal parts https://s3.amazonaws.com/s3.supplyhouse.com/product_files/Lochinvar-NKC110N-Replacement.pdf

GroundUp

There is essentially a 3 way zone valve inside the boiler cabinet which diverts the water through the internal plate HX instead of through the close tees or hydrosep, during DHW call. Everything else is the same, and uses the same internal piping & circ.

hot_rod

But you may or may not be able to direct pipe to a system. Primary Secondary or a hydraulic separator may be required. The boiler needs a minimum flow rate, the installation manual has the info to guide the piping options