Safety Valves; Connecting Cold And Hot Water Pipes; Connecting Supply And Return Pipes; Fill And Bleed The Heating System - Danfoss DHP-AL Installation And Service Instructions Manual

5.2

Safety valves

• Radiator systems with a closed expansion tank must also be
equipped with an approved pressure gauge and safety valve,
minimum DN 20, for a maximum 3 bar opening pressure, or
according to country specific requirements.
• Cold and hot water pipes as well as overflow pipes from safety
valves must be made of heat resistant and corrosion-resistant
material, e.g. copper. The safety valve overflow pipes must have
an open connection to the drain and visibly flow into this in a
frost free environment.
Connecting pipe between the expansion tank and the safety valve
must slope continuously upwards. A continuous upwards slope
means that the pipe must not slope downwards from the horizon-
tal at any point.
5.3

Connecting cold and hot water pipes

1. Connect the cold water and hot water pipes with all the neces-
sary components.
5.4

Connecting supply and return pipes

If the heat pump installation is equipped with a separate water
heater, an exchange valve must also be installed on the heating
system's supply pipe, see above system layout.
All pipes should be routed in such a way that vibrations cannot be
transmitted from the heat pump through the piping and out into
the building. This also applies to the expansion pipe. To avoid the
transmission of vibrations, we recommend that flexible hoses are
used for the supply pipe and return pipe on both the heating sys-
tem and brine system sides. Flexible hoses are available to purchase
from Danfoss AS. The following figures show how appropriate and
inappropriate installations look using this type of hose.
To avoid noise caused by pipe mounting, rubber-coated clamps
should be used to prevent the transmission of vibrations. However,
installation should not be too rigid and the clamps must not be too
tight.
Figure 21: Do not twist the flexible hoses as they are installed. At
threaded connections, use a counterhold spanner.
Figure 22: Cut the hose to the correct length to avoid excess bowing-out
or stretching at bends.
Figure 23: Cut the hose to the correct length to avoid excess bowing-
out or stretching and offset the ends so that the hose is not installed
Figure 24: Use fixed pipe bends to avoid excess stress on bends next to
1. Connect the supply pipe with a flexible hose connection and
with all the necessary components.
2. Connect the return pipe with a flexible hose connection and
with all the necessary components including a filter.
3. Insulate the supply and return pipes.
4. Connect the expansion tank to the expansion outlet (22mm Cu)
on the top of the heat pump.
5.5

Fill and bleed the heating system

1. Fill the heating system with water via the filling cock to a pres-
sure of approximately 1 bar.
2. Open all radiator valves fully.
3. Bleed all radiators.
4. Refill the heating system to a pressure of approximately 1 bar.
5. Repeat the procedure until all air has been removed.
6. Leave the radiator valves fully open.
5.6

Bleed the water heater

1. If the water heater is of the stainless steel type, it must be bled
via the bleed valve on top of the water heater.
VMBME102
completely straight.
connections.
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