3
1.
Description of construction
The combined heat accumulation tanks allow the connection of several heat sources. The main part of the
storage tank is the external tank in which the hot heating water is stored and is made of black steel plate,
while the inner tank is designed for heating HWS and is made of steel plate coated with a layer of enamel.
The flange of cold water from water main inlet, the flange of hot service water outlet and also the connection
of circulation are installed in the upper part of the storage tank in the cover of flange. The tanks can be
equipped with two spirals (e.g. for solar system and CH system).
In the inner tank in the cover of flange there is installed the magnesium anode (valve 5/4”)
The following table lists the wall thickness and type of material which are used for manufacturing the storage
tank Aku COMBI:
Combined tank
External/
/inner
diamete
r
[Ø]
Bottom
M
a
te
ria
l
Shell
M
a
te
ria
l
material thickness
material thickness
Nominal
[mm]
Minimal
[mm]
S2
3
5
J
R
Nominal
[mm]
Minimal
[mm]
S2
3
5
J
R
500/160
700/550
4/3
3/2,5
3/3
3/2,5
600/200
700/550
4/3
3/2,5
3/3
3/2,5
800/200
900/550
4/3
3/2,5
4/3
3/2,5
1000/200
900/550
4/3
3/2,5
4/3
3/2,5
2.
Installation of the storage tank
The connection of storage tanks must be carried out by fitter who holds the appropriate licence. Installation
must be confirmed in the certificate of warranty. The storage tank with regard to its construction must be
installed VERTICALLY. The storage tank must connected directly to a water network ( with the possibility of
disconnection for the purpose of maintenance) with pressure not exceeding 0.6 MPa, but the minimal
pressure must not be lower than 0.1 MPa – approx. l atm. In the event that water pressure in the water
main exceeds 0.6 MPa it must be reduced using a reduction valve. n the cold water inlet pipe there must be
installed a safety valve. The drain valve of the safety valve always must be left open and be in contact with
the atmosphere. It is permitted the connection of the storage tank so as to achieve several points where the
water can be taken from. The spiral in the heat exchanger can be supplied from a low-temperature boiler
operated in the open system or from a boiler operated in a closed system (with an expansion reservoir).
First fill the tank with service water (inner tank) and only then fill the tank with heating water (external
tank)!
3.
Type defects, their causes and remedies
no.
defect
Cause
Remedy
1
Safety valve does not open
(neither after blowing
through)
The safety valve is sealed.
Clean or replace the valve
2
The safety valve is leaking.
Safety valve contact surfaces are
dirty or damaged.
Clean or reface the valve contact
surfaces.
Too high water pressure in the
network
Use a pressure reduction
3
Water in HWS tank is dirty
Too much sediment or worn
magnesium anode
Remove debris from the tank or
replace magnesium anode - is not
covered by the warranty
Between the flanged connections of cold and hot water and the piping in the installation it is
necessary to use dielectric couplings (plastic - non-conductive) to avoid direct contact between
copper and iron and also if the valve or a safety set was connected directly to the equipment. In this
way the service life of the tank is prolonged and the effect of electrolysis is prevented especially
when the water is acidic (pH<7).
