17
Section 6 - System Installation
Digging the Trench
WARNING
Before digging, be sure to call for utility locator
service.
The trench depth for ThermoPEX should be between
10" and 28" (25 and 71 cm).
Fig. 18
Ground Level
End View
ThermoPEX
®
6" to 24" (15-61 cm)
Underground Electric Wire
A 12-2 (two wires plus ground) underground rated wire
should supply the outdoor furnace with electricity. A
heavier gauge wire may be needed if the run is over 200
feet (61 meters). Check local codes and requirements. A
20-amp circuit is recommended.
Connecting to Existing Heating System
1. Make an entrance into the building(s) where the
supply and return lines are to enter.
2. Lay the ThermoPEX assembly in the trench and
feed one end into the building. Apply sealant around
the supply and return lines where they enter the
building.
3. Purge the supply and return lines before connecting
any fittings to ensure there is no debris or foreign
matter present.
NOTE: All holes made in basement or building
walls must be sealed completely to prevent water
from entering the building.
4. Close all valves on the outdoor furnace.
5. Install fittings to allow pressure-testing of both
supply and return lines. Pressurize with 50 psi (3.5
kg/cm
2
) of air; then check after 30 minutes to see if
pressure has dropped. A drop in pressure indicates a
leak; repair as necessary.
6. Connect the supply and return lines to the outdoor
furnace and the existing heat emitter(s). Fig. 19
shows some of the PEX fittings and tools used in
making connections.
NOTE: The base on the back of the outdoor
furnace is removable if necessary for connecting
the supply and return lines to the outdoor furnace.
Fig. 19
Cinch Tool
or
Ratchet Cinch Tool
PEX Brass Clamp Fittings
Wrench
or Socket
Stainless Steel Clamp
Crimp Ring
PEX Crimp Ring
PEX Crimp Ring Tool
Push Fit Fittings
Stainless Steel 1" Hose
Clamp
Wrench
or Socket
No Tool
Required
PEX Fittings and Tools
CAUTION
Allow for expansion and contraction of the
supply and return lines at each end. Without
an allowance for expansion and contraction,
the lines may kink or the fittings may be pulled
apart, causing an immediate water loss from the
outdoor furnace. Central PEX water lines can
have an expansion and contraction rate up to
.095" per each 100 ft and each 10°F (2.4 mm/30
m/5.5˚C).
7. Make sure there are no leaks in the supply and return
lines; then backfill the trench.
NOTE: Do not backfill the trench until the supply
and return lines have been tested to ensure there
are no leaks.
Backfilling Water Line Enclosure
Using gravel or small rock, backfill the perimeter of the
water line enclosure to the top, inner edge of the base
(Fig. 20) to keep out rodents. Install the back and side
panels.
Fig. 20
