tjernlund whke millivolt interlock kit (compatible with uc1 control) 8504108 rev 0802 Manuale Utente

The gas pressure switch is mounted on the casing of the water heater adjacent to the heater's thermostat/gas control valve.  It should be
mounted close enough so that the supplied 1/4" tubing will reach from the gas pressure switch fitting to the thermostat/gas valve pres-
sure tap port. The two provided screws are self-tapping and drilling. The screws do not require the use of a drill and their 1/2" length
assures that the inner tank will not be penetrated.

1. Mount the gas pressure switch by securing it to the heater casing with a screw in each of the two mounting holes.  

2. Install the supplied 1/8"-NPT pipe plug to the 90

o

port of the supplied 1/8-NPT black pipe tee, (See Diagram C).  

Use thread sealant, do not over tighten.

3. Install the 1/8-NPT black pipe tee to the gas pressure switch, (See Diagram C).  Use thread sealant, do not over 

tighten. CAUTION: Utilize the hex nut on the gas pressure switch when attaching the black pipe tee.

4. Install the supplied Brass 1/8-NPT male x ¼" compression fitting to the 1/8-NPT black pipe tee, (See Diagram C).  

Use thread sealant, do not over tighten.

5. Remove the PRESSURE TAP plug from the underside of the thermostat/gas control valve and install the supplied Brass 

1/8-NPT male x ¼" compression fitting, (See Diagram C).  Use thread sealant, do not over tighten.
IMPORTANT: DO NOT alter the heater's PILOT GAS LINE,  (See Diagram C).

6. Using a tube cutter, cut the appropriate length of the supplied 1/4" tubing to reach from the gas pressure switch fitting to the 

PRESSURE TAP PORT fitting of the thermostat/gas control valve.  Make sure each end of the tubing is not pinched closed.

7. Use the 1/4" tubing to connect gas pressure switch fitting to the PRESSURE TAP PORT fitting on the thermostat/gas control valve.

8. Conduct a gas leakage test of all connections as outlined in the latest edition of NFPA 54, ANSI Z223.1, part 4. or local codes.

NOTE: A "gauge port" can be accessed by removing the 1/8-NPT pipe plug that is on the 1/8-NPT black pipe tee (attached to 

the gas pressure switch).

GAS SUPPLY

INTO PRESSURE TAP PORT.

GAS PRESSURE SWITCH

GAS CONTROL VALVE

THERMOSTAT/

FIGURE 700S107    2/13/04

INSTALL BRASS 1/8-NPT MALE
x 1/4" COMPRESSION FITTING

THERMOCOUPLE

BURNER GAS LINE

COMMON

BRASS 1/8-NPT MALE x 1/4"
COMPRESSION FITTING

THERMOSTAT / GAS CONTROL

TO PRESSURE TAP FITTING OF

1/4" OUTSIDE DIAMETER

ALUMINUM TUBING - CONNECT

VALVE.

1/8-NPT BLACK PIPE TEE

1/8-NPT PIPE PLUG - NEW
PRESSURE TAP PORT

NORMALLY OPEN

MOUNTING HOLES

DIAGRAM C