4. Install the new powerhead (See Fig. 4).
Place the manual opening lever (normally
closed models only) on the new powerhead
in the MAN. OPEN position.
Fit the powerhead onto the valve body,
ensuring that the shaft seats correctly. The
powerhead should be aligned so that the
manual opening lever or slot is at the port A
end of the valve body.
Secure the powerhead to the valve body with
the 2 screws provided.
If fitted, reconnect the conduit or cable.
Reconnect the leadwires to the powerhead.
Replace powerhead cover.
5. Turn on power.
On 24 V systems, never jumper the valve coil
terminals even temporarily. This may burn out
the heat anticipator in the thermostat.
Normally closed models
With the manual opening lever set to AUTO and the
powerhead energized, the valve is opened as shown in
Fig. 6A. When the powerhead is de-energized, a spring-
return mechanism drives the valve to the closed position
as shown in Fig. 6B. The valve can also be opened with
no electrical power by moving the manual opening lever
over the stop and pushing slowly and firmly to the MAN.
OPEN position. The stop permits the valve to be locked
in the open position. The valve will return to automatic
position when the valve is energized.
Auxiliary switch is not energized when valve is manually
Normally open models
When the powerhead is de-energized, a spring-return
mechanism drives the valve to the open position (Fig.
6A). When energized, the valve is closed as shown in
Fig. 6B. A reverse-acting thermostat is required to control
a normally open valve.
Automation and Control Solutions
Honeywell International Inc.
1985 Douglas Drive North
Golden Valley, MN 55422
NOTE: Inlet Port is stamped "A", Outlet Port is stamped
"B" on the valve body.
1. Raise the set point on the zone thermostat above
room temperature to initiate a call for heat.
2. Observe all control devices - the valve should open
and the auxiliary switch should make the circuit to
the circulator or other valve at the end of the open-
3. Lower the set point on the zone thermostat below
4. Observe the control devices. The valve should
close and auxiliary equipment should stop.
This valve should be serviced by a trained, experienced
1. If the valve is leaking, drain the system and check
to see if the O-ring needs to be replaced.
2. If the gear train is damaged, replace the entire
powerhead assembly. See Installation. If motor is
burned out, replace motor. See Replacement Parts
list in TRADELINE® Catalog.
NOTE: Honeywell zone valves are designed and tested
for silent operation in properly designed and
installed systems. However, water noises may
occur as a result of excessive water velocity.
Piping noises may occur in high temperature
(over 212° F [100° C]) systems with insufficient
® U.S. Registered Trademark
© 2010 Honeywell International Inc.
T.D. Rev. 09-10
Printed in U.S.A.
Fig. 6. Valve.