Nibe VPA 300 User's And Installer's Manual page 15

Hard water areas
Usually, it should not be a problem installing
VPA 300/200 in areas of hard water as the operating
temperature is 50-60 °C.
Pipe connection
The water heater must be supplied with a thermometer
and pressure gauge as well as a shut-off valve, drain
valve, non-return valve, mixer valve, safety valve, and
vacuum valve as per applicable standards.
The water heater must be provided with a mixer valve,
which limits the temperature of outgoing hot water to
60 °C. If this valve is not fitted, some other measure must
be taken to prevent the risk of scalding.
The safety valve must have a maximum opening pressure
in accordance to the applicable regulations (however
max 6 bar/0.6 MPa). The overflow pipe must be the same
size as the safety valve. The overflow pipe must be routed
downwards along its entire length and be frost proof. It
must run out unobstructed over the drain.
Commissioning and adjusting
Filling the water heater
Fill as follows:
1. Open a hot water tap in the system.
2. Open the shut-off valve on the incoming cold water.
This valve should then be fully open during opera-
tion.
3. The hot water tap can only be shut off when the
water heater is filled, which is when only water
comes out of the tap (initially an air-water mixture
comes out of the tap).
Filling the climate system
Fill as follows:
1. Connect the nessesary valves to the system between
the incoming cold water pipe and the heating sys-
tem. Open the filling valve. The primary part of the
VPA 300/200 can now be filled with water.
2. After a while the pressure gauge, if installed, will
show rising pressure. When the pressure reaches the
set pressure a mixture of air and water starts to
emerge from the pressure relief valve (not supplied).
The filling valves are then closed.
3. Turn the pressure relief valve until the boiler pressure
reaches the normal working range (0.5 - 1.5 bar).
When filling the heating system, the double-jacketed
space should be vented by opening the air nipple
(QM20) (VPA 300/200). The air nipple can be closed
when water comes out of the air hole.
4. Vent the heating system through the pressure relief
valve and the air nipple (QM20) (VPA 300/200). The
remainder of the heating system is vented by means
of each venting valve.
5. Keep topping up and venting until all air has been
removed and the pressure is correct.
VPA 300/200
Cleaning the climate system
When the water heater and the climate system have
been filled with water, VPA 300/200 must operate at
maximum normal temperature for at least one hour.
Thereafter the system must be drained of water and re-
filled.
Emptying the system by
1. Open external filler valve and external drain valve.
2. Flush the system for some minute. Watch out for
water splashes from the safety valve.
3. Close the valves and check the stainer.
Pressure drop diagram
VPA 300/200
Pressure drop
Tryckfall
(kPa)
(kPa)
3,0
2,5
2,0
1,5
1,0
0,5
0,0
0,0 0,1 0,2 0,3
Flow
Flöde
0,4 0,5 0,6 l/s
Chapter 3 | For the Installer 15