Installation; Maintenance And Service - Buderus Logafix BU-H Montage- Und Bedienungsanleitung

EN
1. General
This manual is for Logafix expansion vessels with a capacity of 12 to 80 litres. The package includes an expansion vessel (A)
with label (B), a manual (C) and an installation kit (D) (fig. 1, 12). See the label for the max. working pressure, pre-charge and
max. temperature on the diapraghm. Logafix expansion vessels are pressure equipment, and conform to Pressure Equipment
Directive 2014/68/EC. A conformity declaration can be obtained from Buderus.
Application
Logafix expansion vessels are intended for use in closed central heating and cooling systems (BU-H and HP) and closed solar
energy heating installations (BU-S) (using additives based on up to max. 50% glycol). Refer to the Buderus documentation to
calculate the capacity and pre-charge.
Safety
The expansion vessel comes pre-charged. Damage may result in serious injuries. The bracket must be able to carry the
weight of a full expansion vessel. Prevent overpressure in the installation. Install a safety valve.
Set the opening pressure of the safety valve to a value that is equal to or lower than the maximum working pressure shown on
the label. The connection between the expansion vessel and the boiler must always be open.

2. Installation

The installation must be carried out by approved personnel only.
Observe local regulations and guidelines.
Flush the installation before installing the vessel (never via the safety valve) and check the installation by examining it for leaks.
Fitting
• Expansion vessels with a capacity up to 25 l (35 l for BU-S) are installed suspended from the water nipple (E). (fig. 2, 13)
• Expansion vessels with a capacity between 35 (BU-H and HP) and 80 litres are installed either with the water nipple (E)
pointing down, or standing on the floor. (fig. 3)
1. Apply plastic tape (G) (do not use hemp!) to the connection of the expansion vessel (fig 4, 14). Choose a seal that is suitable
for the maximum temperature and the liquid used!
2. Screw the expansion vessel to the installation.* Install the vessel so that the water it contains cannot circulate.
* BU-H and HP: Install the vessel in the return line, as close as possible to the boiler, on the intake side of the pump.
* BU-S: The vessel must be installed as close as possible to the pump on the pressure side.
First use BU-H and HP
a. Open the bleed points. (fig. 5, 6)
b. Fill the installation slowly until the fill pressure in the
expansion vessel is 0.2 bar higher than the pre-charge.
Bleed the system during filling. (fig. 7)
c. Bleed the pipe to the expansion vessel. (fig. 7)
d. Close the bleed points. (fig. 8)
e. Heat the system as high as possible for half a day and
bleed regularly.
f. When the water temperature has fallen to approx.
50 °C, top up the installation to 0.5 bar above the
pre-charge of the expansion vessel. Ensure that the
filling hose is bled.

3. Maintenance and service

It is recommended that the expansion vessel is checked annually by approved personnel.
4. De-installation
1. Allow the installation to cool down and release the pressure from it.
2. Remove the cover cap (H) and the plug (I). (fig. 9, 18)
3. Push the inner valve (J) in to drain the pressure from the expansion vessel. (fig. 10, 19)
4. Unscrew the expansion vessel (A). (fig. 11, 20)
Caution: a full expansion vessel is heavy!
The water in the expansion vessel may be hot.
Observe the local regulations when you dispose of the expansion vessel.
| Installation and operating instructions
English
First use BU-S
a. Calculate and set pre-charge.
• Remove protective cap (H) and valve cap (I). (fig. 15)
• Measure the pressure.
• If the pressure is too high, allow gas to discharge through
the gas valve; if the pressure is too low, fill with expansion
gas. Nitrogen must be used as filling gas. (fig. 16)
• Replace protective cap (H) and valve cap (I). (fig. 17)
b. Calculate filling pressure.
c. Fit the vessel in the installation.
d. Slowly fill the installation until the filling pressure is
reached. Bleed the system during filling. Follow the
directions of the manufacturer!
e. Check the seals for leaks.
f. The expansion vessel is now ready for use.
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