Application Guide

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© 2016 tekmar 670
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A - 10/16
Shared Boiler and Heat Exchanger A670-3 Mechanical
Application Settings
Setting Name Value
Application Mode PWM Zone
Boiler Type Enable
A1 = Normally Closed Freeze Protection Aquastat
B1 = Boiler Enable
HX = Heat Exchanger
P1 = System Pump
P2 = On/Off Heat Exchanger Pump
S1 = Snow/Ice Sensor 090 or 094
S2 = Snow Sensor 095
S3 = Slab Sensor 072 or 073
S4 = Outdoor Sensor 070
Legend
670
Snow/Ice Sensor Options
S4
P2
A1
P1
S1
S2
S3
HX
Description
The WiFi Snow Melting Control 670 operates a snow melting zone warmed from a heat source that is shared with other loads
in a building. A heat exchanger isolates the glycol-filled snow melting system loop from the water-filled main heating system.
• The system pump operates continuously when heating the slab during melting/idling/storm operation.
• The slab temperature is controlled by cycling the heat exchanger pump and the boiler enable on and off.
• The slab target is determined by the melting/idling/storm setpoint and by the measured outdoor air temperature.
• A normally-closed aquastat protects the heat exchanger from freezing by shutting off power to the system pump.
The system operation is dependent on sensor selection, as listed in the table below.
Sensor options Operation methods
Sensor Sensor Model(s)
Auto Start/
Auto Stop
Auto Start/
Timed Stop
Manual Start/
Timed Stop
Slab Temperature
Control
S1 Automatic Snow/Ice Sensor 090 or 094 • – • •
S2 Aerial Snow Sensor 095 – • • –
S3 Slab Sensor 072 or 073 – – • •
S2+S3 Aerial Snow Sensor 095 and Slab Sensor 072/073 – • • •