Operating instructions
6 Operating instructions for auroSTOR 0020111120_01
3  Description of the unit
The auroSTOR solar cylinder is available in three sizes: 
210, 260 and 310 litres and meets the requirements of 
EN 12897:2006. The cylinder is made from stainless 
steel and is insulated with EPS with heat radiation 
absorbers. 
The cylinder works with the pressure of the water supply 
line and does not need a cold water tank for its supply. 
To enable the cylinder to work as well as possible, a cold 
water supply with an appropriate pressure and flow rate 
is required.
Hot water temperature control
You can set the hot water temperature and primary 
heating times in the upper half of the cylinder on the 
controller. One of the following controllers may be used 
depending on the design of your system:
 – Vaillant auroMATIC VRS 560/2 solar controller or 
 – Vaillant dual-channel eBUS controller
 – Cylinder thermostat in conjunction with a timer
Observe the operating instructions for the installed 
controller or timer.
Electric immersion heater
The cylinder is equipped with an additional electric 
immersion heater with a heating output of 3 kW. The 
electric immersion heater is located behind the top front 
cladding. The electric immersion heater is designed for 
use in unvented cylinders and has a thermostat with a 
temperature controller and a thermal cut-out (TCO) with 
a reset button.
Safety devices
The solar cylinder has been provided with all safety and 
control devices for operation of the unvented domestic 
hot water supply:
 – Temperature/pressure relief valve (90 ºC, 7bar)
 – Pressure reducing valve (3.5 bar) with line strainer
 – Expansion relief valve (one-way valve, 6.0 bar) 
 – Solar pump thermal cut-out, set to 80 ºC, connected with 
the solar pump in order to isolate this heat source if 
there is a fault in the solar control. 
 – Thermal cut-out for electric immersion heater
 – Solar cylinder thermal cut-out, set to 80 ºC, to be con-
nected to the two port motorised valve in order 
to isolate the primary heat source if a domestic water 
supply thermostat fault occurs.
Solar heating system
The Vaillant solar heating system is a closed hydraulic 
system in which the special heat transfer fluid of the 
solar heating system transfers the heat to the water 
in the cylinder via a heat exchanger.
The water in the auroSTOR solar cylinder is heated 
by two separate circuits.
The cooler water in the lower part of the cylinder is 
heated by the solar circuit. The relatively low water tem-
peratures in the lower section ensure optimum heat 
transfer from the heat exchanger of the solar circuit 
to the water in the cylinder even if the solar radiation 
is low.
The warmer water in the upper part of the cylinder is 
heated by the gas-fired wall-hung boiler in the primary 
heating circuit or by an electric immersion heater. The 
ready-to-use volume in the top part of the cylinder 
amounts to around half of the total cylinder volume.
3 Description of the unit










