Specifications

17
5.1 freewatt Hydronic Zone Thermostat
Requirements
:
Select heat or heat/cool thermostat with following
properties, except Zone-2. Zone 2 must use HAI Smart
Zone Thermostat.
Use isolated relay contacts to switch W call for heat •
signal.
freewatt expects 24VAC “HOT” connected
to thermostat’s “R” terminal to pass directly thru
thermostat’s W relay to drive “W” signal back with
minimal loss of signal voltage when calling for heat.
Thermostat’s W relay must present high-impedance •
(ie. no current fl ow) when open, not calling for heat.
Thermostat must not add resistive elements to W •
signal path (resistors, voltage divider networks,
MOSFET(s), transistors, etc.) when not calling for
heat. Open circuit impedance of W signal path must
be greater than 100,000 ohms, and preferably higher
(ie 1 Megohms or more).
5.2 Known Problematic Thermostats:
Honeywell T87N, T87K •
5.3 Known Compatible thermostats:
HAI Omnistat1, Onmistat2•
LUX 1500•
Braeburn Model 3000•
5.4 Tests For Thermostat Compatibility:
Resistance test: •
Thermostat calling for heat, W relay closed: •
Thermostat relay impedance must be less than 40
ohms when measured across thermostat R and
W terminals. Impedance greater that 40 ohms
is unacceptable and will not work reliably with
freewatt PLUS System.
Thermostat not calling for heat, W relay open: •
Thermostat relay impedance should be greater than
1 Megohm (1 million ohms).
Voltage test:•
AC voltage measured between 24V common •
terminal on circuit board J02 connector (labeled
24VAC - bottom of board) and circuit board J02 W1,
W3 or W4 terminals (top of board) must be less
than 1.5 Volts AC when no call for heat, attached to
freewatt PLUS System and powered by 24 to 28
volts AC from freewatt Control Module. Thermostat
not suitable for use with freewatt PLUS System if
voltage is greater than 1.5 Volts AC.
Voltage must be greater than 20 Volts AC, when •
thermostat calls for heat. Thermostat is not suitable
for use with
freewatt PLUS System if voltage is
less than 20 Volts AC.
5.5 Communication Registers On RC-1000 Smart
Zone Thermostat:
Apply factory reset to restore communications on RC-•
1000-WH-ECR.
P ress (“click”) on scroll wheel to start.
Select “Setup”. •
Select “Installation Settings”. •
Notice warning for installers. Press “Continue”.•
Select “Factory Reset” (last item in list). •
Press “Back” as required to return to normal operation. •
All settings, including setback programming have been
cleared.
5 - COMPATIBLE ROOM THERMOSTATS