Adding Mixing control (Tekmar 356) to regulate water temperature to radiant

sma1123

I'm a homeowner with a new radiant subfloor install. System is noisy with pex expansion. Plumbing company rep mentioned using a mixing control (Tekmar 356) with outdoor reset to regulate the temperature of the water to help with potential expansion noises. (Boiler is navien mod/con) Is this something that can be added post-design or does it require a complete repiping?

Rich_49

Is the whole house radiant floor ? What model Navien do you have ? Why does your radiant floor not have outdoor reset installed originally ? What circulator/s are currently being used ?

Ironman

I have to ask the same question as Rich: why wasn't ODR installed with the floor? Or with the Navien?

If there are no other zones but the floor, the mod/con can control ODR with the optional outdoor sensor installed and setup properly.

If you have to use the Tekmar 356, then repiping and an additional circ is required.

sma1123

There is an outdoor reset. It was probably a stupid question. I assumed that the tekmar complemented the ODR. I am not that knowledgeable. The noises happen when the heating cycles. when it's steady no issues ... it's awesome. Incredible warmth. Stays on 2-3 hours and then i hear the thermostat click and the noises start for 10 minutes so. It's very annoying especially taking a nap on the couch. It's only one floor of radiant with baseboard upstairs. The rep said this term 'injection control' to regulate the temperature so it sounded like something different. I do have ODR and mixing control so that sounds like it does the same thing.