DORCHESTER DR-FC 25, Installation, Commissioning And Maintenance Instructions

Page: 24 / 98

Installation
24 Instruction Manual DR-FC
3
is
3.6 Water connections,
Unvented
3.6.1 Cold water side
See
a
in Figure 3.3 .
1. Fit an approved stop valve
c
on the cold water side as required by
regulations.
Refer also to paragraph
’1.3 Regulations and documents’ .
2. The maximum working pressure of the water heater is 8 bar. Because the
pressure in the water pipe at times can exceed 8 bar, you must fit an
approved pressure-reducing valve
a
.
3. Fit a non-return valve
d
and an expansion vessel
m
.
4. Fit an expansion valve
l
and connect the discharge to a drain via a tundish.
3.6.2 Top to bottom recirculating pump
You can connect a top to bottom recirculation pump to prevent stratification of
the water ("stacking")in the water heater.
1. Fit a pipe (Ø 22 mm), a stop valve
c
and a top to bottom recirculation
pump
e
.
2. Fit non-return valve
d
.
3. Fit stop valves
h
.
3.6.3 Hot water side
See
b
in Figure 3.3 .
n
Remark
Insulating long hot water pipes prevents unnecessary energy loss.
1. Optional: fit a temperature gauge
i
to be able to check the temperature of
the tap water.
2. Fit the T&P valve
b
.
3. Fit a stop valve
h
in the hot water outlet pipe, for use when servicing.
3.6.4 Circulation pipe
See
c
in Figure 3.3 .
If an immediate flow of hot water is required at draw-off points, a circulation
pump can be installed. This improves comfort and reduces water wastage.
1. Fit a circulation pump
e
of the correct capacity for the length and resistance
of the circulation system.
2. Fit a non-return valve
d
a downstream the circulation pump to guarantee the
direction of circulation.
3. Fit two stop valves
c
for service purposes.
4. Connect the circulation pipe to the cold water supply pipe.
3.6.5 Condensation drainage
1. Fit a sloping wastewater pipe to the siphon
j
for condensation drainage and
connect this to the wastewater discharge in the boiler room.
c
Note
All piping behind the siphon must be condensation-resistant.