Navien Combi 240 - SH Temp Settings for Winter

TylerB23

Hey all!

This is my first winter using a Navien Combi Boiler for in-floor radiant heading. I'm just wondering what temperature setting I should be using for Space Heat and if there are any other settings I should be using during the winter vs summer. At the moment, I have SH set at 130°F - the outdoor temperature is -15°C (5°F). The floors aren't super warm, but I'm getting decent heat - thermostats are set at 70°F.

Is 130°F a good SH setting or is it too low/high?

The Outdoor Thermostat was NOT installed, which I'm sure makes a difference, so I'm looking into getting that done.

Thank you!

Jamie Hall

One can debate numbers all day long -- but the real question is, is 130 F the right temperature to provide the heat you need from the floor with the system running most, if not all, of the time? If it is, it's the right temperature. If the system is cycling on an off, try a slightly lower temperature. If you're not warm enough, try higher -- but I expect that 130 is about as high as you'd want to go, to protect the floor.

Ironman

Was a Manual J load calculation done?

There’s no “one size fits all” answer to your question. The design temp for your locale, the actual heat loss of your house, the tubing layout, etc, all factor in.

Is this a slab radiant floor or a “staple up” to a wooden floor? Were heat transfer plates used if it’s a wooden floor?

You really should connect the outdoor sensor and get the ODR function set up on the boiler, but again, you’ll need the info requested to get it right.