Smith's Heating First PWU 4/6 Installation & User Manual

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 bottom
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 field supplied thermostat should be a line voltage
thermosat.
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 recess units are designed for years of trouble free operation.
If servicing is required, please contact the installing contractor or
Smiths Environmental Products
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 110°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
Customer Service
300 Pond Street
Installation & user Guide
PWU
PWU 4/6
PWU 6/8
PWU 8/10
PWU 13/15