1
3
2
4
52 mm
HOT WATER CONNECTIONS
sound insulation
mat, 30 mm
floor hatch
heating unit
cover
electrical connections
heating insert
heating unit box
hole for water pipe return
hole for water pipe inlet
Install the heating unit boxes in the correct location,
with the height adjusted so that the lid is flush with
the concrete surface, before pouring the concrete.
Refer to the instructions on the box cover.
1. Run conduit from one of the cable inlets on the
box to the local disconnect for 230V power.
Run conduits from the remaining cable inlets
to a convenient location above the slab for
each of the 24V thermostats, external 24V
transformer (not supplied) and optional signal
wiring to the boiler.
2. Connect the sleeves for the inlet and outlet
water pipes to the water pipe connections of
the furnace box. Install the water pipes, and
make sure they extend at least 100 mm (4")
into the box.
3. After the concrete has dried sufficiently with
the construction heater, prepare the box for the
heating unit according to the steps below, which
are performed by an authorized electrician and
plumber.
4. Clean the furnace box carefully. No water or
dampness should be in the box or pipe system
when installing the permanent insert.
ASSEMBLY
1. Install threaded adaptors with integral gasket
for ½” NPSM (lavatory-style straight threaded)
on water pipe, and adjust pipe to length so that
the end of the fittings stick 52 mm (2") inside
the box as shown in picture 1.
2. Loosen the two vertical pipes with their elbow
connections, which are loosely mounted on the
heating unit for mounting of inlet and return water
pipes. Then mount the lower
elbow connections
t
o the water pipes, as shown in picture 2.
3. Mount the heating insert, so that the vertical pipes
stick into the elbow connection above and tighten
the joints. See pictures 3 and 4.
4. Turn on water and check for leaks.
5. Once the electrical connections have been
completed, bleed any air from the system after
a test run.
water pipe
connections
electrical
connections
4000W
heating unit box
4000A 50/50
Heating unit box
4000A 100/100 is
similar
www.legalett.com
#2.
#3.
#1.
#4