2-wire thermostat in DHC port ?

BenoitG

I wish to make changes in how my system works. It will only be possible if a use the Hot Water port (DHW) in the control box with a regular thermostat (RW). DHW is meant for an Aquastat.
My control box is a Tekmar 306V. There are two slots for the wires under DHW. I feel a non-stealing thermostat (2 wires) could be use there. Is it so?
I have 4 zones: 3 in the basement (radiant) and a big one for the other two stories of house. That zone is composed of 6 hot water radiators. (It is an old house with a brand new basement.) I just discovered that letting the pump of the radiators runs all the time provides a lot more confort. Even better, I don't hear the cooper pipe expanding every hour or so (it was noisy, it is an old house). And there are other benefits, the boiler room isn't so hot anymore and, I have yet to validate this, I think the boiler isn't working as much. So, I wish to reorganize my wiring so the pump will always run. The relay box has a "priority" feature I can re-purpose. There other issues but it all come down to : can I use the HDW port (aquastat) with a regular 2-wire thermostat ?

mattmia2

An aquastat is just a switch like a conventional thermostat. they provide the same type of contact closure control signal. i don't know enough about what you are doing to know if using that terminal will cause some other problem like the wrong pump(s) to run, use the wrong setpoint, or defeat outdoor reset or anything like that.

Jamie Hall

A point to remember. That domestic hot water port is a priority port. If that thermostat is calling, the other pumps will turn off and the boiler may ramp up to a domestic hot water setting. You may be able to defeat that...

BenoitG

There is a dip switch to turn off the priority. So, yes, I can defeat that. Thanks for mentioning.