In fairness to all, we don't discuss pricing on the Wall. Thanks for your cooperation.
Given the following scenario:
(2) oil-fired boilers stage/rotate
(2) zones of cast-iron radiators
(2) zones of low-mass radiant (heat transfer plates under wood subfloor)
Indirect DHW using the tekmar sensor
Each zone has a separate circulator. The two radiant zones operate at different temperatures, and are mixed by a tekmar 3-way mixing valves (manual, no motors).
Each zone has a switching relay (old honeywell 89A equivalent). A call from a thermostat closes the relay. The relay then applies power to the boiler demand terminals on the 274.
The idea was to let the zones fly on the ODR. However, radiant has a different reset curve than the CI rads. Not the end of the world.
I was curious if adding 541 thermostats (or another TN4 thermostat) for the radiant zones would be advantageous?
If I am understanding correctly, I could set the 274 to use the CI reset curve. When the CI zones call for heat, the boiler demand terminals are closed and the CI reset curve is used.
If the radiant zones call for heat, the TN4 thermostat would communicate over the TN4 bus and the low-mass radiant reset curve would be used.
Am I understanding correctly? Any suggestions?