AERCO Esteem O&M Manual - Manual (Page 47)

41
Check Thermostat Circuit
Check Thermostat Circuit
1. Disconnect the external thermostat wires
from the 24V terminal strip on the wiring
panel.
2. Connect a voltmeter across the wire ends
of the external thermostat wiring.
3. Close each thermostat, zone valve and
relay in the external circuit one zone at a
time and check the voltage reading across
the wire ends.
There should NEVER be voltage measured at
the wire ends.
1. If voltage is measured at the panel under
any condition, check and correct the exter-
nal wiring.
N
OTICE
In systems using 3-wire zone valves,
feedback of voltage to the unit is a com-
mon problem. Use an isolation relay to
prevent voltage from the external circuit
entering the Esteem 399 Low NOx con-
trol panel.
2. Reconnect the external thermostat wires to
the 24V terminal strip on the wiring panel.
Inspect the Condensate Drain
Assembly
1. Inspect and ensure the Condensate
Drain Assembly is properly installed as
described on page 27 and shown in Figure
16 on page 28.
2. Remove the plug from the Condensate
Drain Assembly and fill with fresh water.
N
OTICE
The condensate drain assembly must
be fi lled with water when the Esteem
399 Low NOx is in operation. The con-
densate drain assembly prevents fl ue
gas emissions from entering the con-
densate line. Failure to ensure trap is
fi lled with water could result in severe
personal injury or death.
3. Re-Install plug in condensate drain
assembly.
GF-125