Auto Feed connection on Navien NCB 210e not used?

JohnJr

This is in relation to another post I made regarding the auto feed connection on the bottom of my Navien NCB 210E combi-boiler. Prior to installation, if this auto feed connection is not used, will my unit fill itself just fine, or is this a 100% required connection that has to be made no ifs, ands, or buts? I live out in the country. Water coming to the house is fed from a well pump which has the main water line coming up through the slab of the house with the water passing through a pressure tank. If this auto feed connection doesn't have to be used, do I have to use another method to fill the combi-boiler or will it feed itself from the domestic cold water inlet? Instructions through Navien are not crystal clear. Legitimate feedback only, no sale pitches.

Jamie Hall

You need some way to feed the boiler -- at the correct pressure. It's quite separate from the domestic cold water inlet, which is for your domestic hot water side of the combi. The automatic feed is connected to the house cold water, but has a valve on it which automatically reduces the pressure to that which is required by the heating side (usually around 15 psi or so) and makes sure that that pressure is maintained.

So... either use that connection, which is by far the simplest way to go, or come up with some other pressure reducing/regulated way...

EBEBRATT-Ed

@JohnJr

Pictures. Did the contractor feed the water into the boiler system in a different location