1C20 (Heat Only Two Wire):
A. Mount base and adaptor plate:
Mount base and adaptor
plate (optional) to wall using screws provided (see Fig. 1).
B. Attach wires:
Attach one wire to R and the other wire to W
on base.
C. Skip to Step #5.
1C26 (Heating and Cooling):
A. Remove base from subbase:
Loosen the three screws
on the base and remove.
B. Mount switching subbase/adaptor plate:
Use the screws
provided to mount the subbase and adaptor plate (optional)
to wall (see Fig. 1).
C. Attach wires to appropriate terminals:
• For two wire systems (Heat Only or Cool Only).
If you
have a two-wire
Heat Only
system, attach one wire to
RH and one to wire W. If you have a two-wire
Cool Only
system, attach one wire to RC and one to wire to Y.
Leave the factory installed jumper between RC and RH
attached. Tighten any unused terminals securely.
• If your system has more than two wires:
Use the cross
reference chart to determine correct wire connections. If
you have a four-wire heat/cool system leave the factory
installed jumper between RC and RH attached (see Fig 2.).
If your system has five wires remove the factory installed
jumper between RC and RH (see Fig 3.).
• Electric heat or single stage heat pump systems:
This
thermostat is configured from the factory to operate a heat/
cool, fossil fuel (gas, oil, etc.) forced air system. It is con-
figured correctly for any system that DOES NOT require
the thermostat to energize the fan on a call for heat. If
your system is an electric heat or heat-pump system that
REQUIRES the thermostat to turn on the fan on a call
for heat, remove the yellow factory-installed jumper wire
from the Y terminal and connect it to the A terminal. This
will allow the thermostat to energize the fan immediately
on a call for heat. If you are unsure if the heating system
MOUNTING AND WIRING
ATTENTION!
This product does not contain mercury. Howev-
er, this product may replace a unit which contains mercury.
Do not open mercury cells. If a cell becomes damaged, do not
touch any spilled mercury. Wearing non-absorbent gloves, take
up the spilled mercury and place into a container which can be
sealed. If a cell becomes damaged, the unit should be discarded.
Mercury must not be discarded in household trash. When the unit
this product is replacing is to be discarded, place in a suitable
container. Refer to
www.thermostat-recycle.org
for location
to send the product containing mercury.
REMOVING OLD THERMOSTAT
CONTINUED FROM FIRST PAGE
4
3
Do not use on circuits exceeding specified voltage.
Higher voltage will damage control and could cause
shock or fire hazard.
Do not short out terminals on gas valve or primary control
to test. Short or incorrect wiring will damage thermostat
and could cause personal injury and/or property damage.
Thermostat installation and all components of the system
shall conform to Class II circuits per the NEC code.
WARNING
!
