Velux TFF 550 0301 Directions For Use Manual Download Page 8

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Recommendation:

In order to equalize pressure fluctuations or water
impact in the cold water circuit and to avoid unne-
cessary water loss, we recommend that you install
a suitable expansion vessel with a flow-through
fitting.

Installation

The tank must be assembled and installed by a certi-
fied specialist company!
When transporting and opening the packaging, the
instructions off all enclosed manuals must be fol-
lowed, in particular those of the anodes. If necessary,
the pre-fabricated CFC free rigid PU shell insulation
can be disassembled to reduce the dimensions when
positioning. The dimensions of the tank may not
exceed the max. insertion dimensions!
The storage tank must be installed in a frost-proof
room with short cable routes.
When installing the unit in an attic, a suitable col-
lecting basin with a drain unit must be provided. The

weight of the filled tank may not exceed the max.
permitted ceiling loading!
The inner hot drinking water tanks, enamelled in
accordance with DIN 4753, Part 1 are suitable for nor-
mal drinking water. Mixed installation is permitted.
It must be connected in accordance with DIN 1988
and DIN 4753, Part 1. All connection sleeves not
used must be closed with plugs.
The operating overpressure ratings specified on
the type plate may not be exceeded. If necessary, a
pressure reducer must be installed.

Insulation

Assembly sequence of the CFC free rigid PU foam
insulation with polystyrene shell:
1. Slide the soft foam seals over the sleeves or at-

tach to the tank.

2. Attach the shells on the tank and slightly close the

flat cradle strap in the middle of the insulation.

3. Place the insulating cover on the shell insulation.

4. Now, adhere the flat cradle strap attached in the

middle to the base and tighten. CAUTION: Over
tightening damages the plastic parts!

5. Attaching the rosettes.

Observe that the insulation and soft foam seals are
fitted tightly on the tank to minimize heat loss!

Commissioning

IMPOrTANT: Initial filling and commissioning must
be carried out by a certified specialist company!
The inner interlocking service water tank must be
filled and pressurized before filling the surround-
ing heating tank. NOTE: If the prescribed filling
sequence for the tank is not observed, the tank
(enamelling etc.) may be damaged!

Sequence:

– Fill the internal tank unit with water! Deaerate at

a sampling point.

– Increase the pressure approximately 2 bar. Check

the flange and anode for leaks.

– Fill the surrounding buffer tank and increase the

pressure on the heating water side to a normal level.

14 VELUX

15 VELUX

Fig.: TFF 550 0301

Fig.: TFF 750/950 0301

– Heat up the tank.
– CAUTION! Large amounts of expansion water are

produced during initial heating. Please observe
that the safety valve is installed correctly and
functions properly or the valve outlet is open.

– Open the cold water supply hose fitting completely.
The safety valve must be checked regularly to ensure

that it functions safely. We recommend that you
have the system serviced annually by a specialised
company. We recommend that the storage tank be
cleaned and checked annually. Careful operation can
save a considerable amount of energy. Do not run
the storage tank at more than 60°C, as this results
in heat loss and limescale.

TFF 550/750/950 0301