When filling the PWU 2/3 recess unit with system water, it will be necessary to remove the air from it. A built in
manual air vent is accessible on the top left hand side of the unit (this is only accessible with the front cover grille
removed). Using a slotted screwdriver turn counter-clockwise until the air is purged (some water may also be bled
along with the air).
Check to make sure that the PWU 2/3 will receive the flow (GPM) required to achieve it’s duty point, it may be
necessary to balance the system to achieve the desired flow rate.
Electrical. ALL ELECTRICAL CONNECTIONS MUST COMPLY WITH LOCAL AND/OR NATIONAL
CODES AND REGULATIONS. IF IN DOUBT, CONSULT A QUALIFIED ELECTRICIAN.
Remove the electrical junction box cover (situated at the bottom right hand side of the unit) by removing the single
junction box cover screw. Bring supply wiring into the unit through the knockout in the lower right hand-side of the
junction box securing the entry point with a connector.
Power Supply
Wire should be 14AWG and protected by a 15AMP over current protector.
Connect line input to black lead,
neutral to white lead and ground to pillar marked G inside junction box.
Start-up
Set the fan speed switch to either
I (low speed)
or
II (high speed)
and activate the system thermostat (field
supplied), because of the integral low limit aquastat, it may take several minutes before the fan is activated. When
the fan does come on, ensure that the switch is operational by moving position to
O (off),
then to
II (high speed).
Best results are obtained by leaving the switch in the
I
position and reserving
II
for a quick heat up or in extreme
conditions. If the unit is not operating please refer to the trouble shooting tips at the end of this manual.
Unit operation.
This Pocket Wall Unit has 2 different controls.
1. An internal aquastat, not operated by the user.
2. A surface mounted rocker switch (situated behind the access door) for the user to operate the fan speeds. Min /
Off / Max.
Press “
I
” for Min. fan speed, press “
0
” for off, press “
II
” for Max. Fan speed.
Room thermostat control
This Pocket Wall Unit may be run by a field supplied remote wall mounted room thermostat wired into the power
supply. Refer to the instructions provided with the thermostat selected. One thermostat can be used to control up
to four heater appliances. This filed supplied thermostat should be a line voltage thermostat.
Alternatively, field supply a low voltage room thermostat that would be wired directly to the circulator for the zone
that the PWU units are installed on. On a call for heat, the circulator would come on and the unit mounted
aquatstat would bring the fan on once the coil temperature exceeded the lower threshold.
Unit maintenance
The Smiths Environmental Products PWU 2/3 recess units are designed for years of trouble free operation.
If servicing is required, please contact the installing contractor or
Smiths Environmental Products
Customer Service
300 Pond Street
Randolph, Ma 02368
Phone: 269 925 8818
Troubleshooting tips
If the unit fails to operate:
1. Verify that the supply voltage is 120V AC, all wires are connected and the fan switch is in the
I
or
II
position.
2. Verify that hot water is going to and through the unit at 130°F or above. Both supply and return tubes should be
hot. If the return is not hot, the coil is air locked, which will prevent the fan from operating when unit is set to
heating mode. Bleed air from the coil if necessary. The unit should run.
3. If the PWU still does not run, replace the aquastat.
Caution:
ELECTRICAL SHOCK MAY RESULT. ISOLATE FROM POWER BEFORE OPENING OR SERVICING
THIS UNIT
Nov 09 PWU2/3
PWU 2/3
Installation & User Guide
