Spartherm Mini Z1 H2O User manual

Installation and
Operating Manual
H2O – fireplace inserts
Mini Z1 H2O
Mini Z1/Z1h H2O XL
Varia 1V/1Vh H2O
Varia 1V/1Vh H2O XL
Varia 1V/1Vh H2O XXL
Varia 2Lh/2Rh H2O
Varia Ah H2O
Varia A-FDh H2O
Note:
Failure to comply with the instructions contained in the installation and
operating manual will invalidate the warranty.
Where details contained in the supplementary assembly manual differ
from the details in the installation manual, such details should only be
taken into consideration if they impose more stringent requirements.
- We reserve the right to make technical
modifications and accept no liability for
any errors - Issued 01/2014
SPARTHERM
Feuerungstechnik GmbH
Maschweg 38
D - 49324 Melle
- 2 -
Foreword / Our philosophy with regard to
quality
You have decided to purchase a Spartherm product – we would like to
thank you for placing your confidence in us.
In a world characterised by excess and mass production, the good name
of our firm is inextricably linked to the credo of our owner, Gerhard
Manfred Rokossa:
“High technical quality combined with modern design and on-site
customer service carried out to the latter’s full satisfaction, in the
expectation that the customer will then recommend us to others.”
To you and our partners in specialist dealerships, we offer first-class
products that stir the emotions, appealing to that sense of security and
comfort that we all feel. However, to ensure that we succeed in this, we
recommend that you read the operating manual carefully to quickly
familiarise yourself with your fireplace insert in all its details. In addition to
information on how to use it, this manual also contains important
maintenance and operating instructions for your safety and to ensure your
fireplace insert retains its value.
It also contains valuable tips and advice to help you. In addition, we show
you how to use your product in a way that will protect the environment..
If you have any further questions please contact your dealer.
A beautiful fire at all times.
Your Spartherm team
G.M. Rokossa

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Contents Page
Foreword / Our philosophy with regard to quality 2
1. General information 5
1.1. Scope of supply 6
1.2. Specification 7
2. Installation 22
2.1. Basic installation requirements 22
2.2. Electrical connection 24
2.3. H2O fireplace insert connections 24
2.4. Minimum crosssections for convection air 32
2.5. Bleeding 32
2.6. Safety valve 34
2.7. Load unit 34
2.8. Overheat discharge valve 35
2.9. Thermal pump control system 36
2.10. Incorporation into a heating system 38
2.11. Chimney connection / connecting piece 53
2.12. Height limitation / door stop 53
3. Initial commissioning 56
4. Operation 57
5. Cleaning and maintenance 59
5.1. Cleaning the heat exchanger 59
5.2. Cleaning the double glazing 61
5.3 Maintenance of the heat exchanger 61
6. Troubleshooting 62
7. General warranty terms and conditions 64
7.1 Scope of Application 64
7.2 General information 64
7.3 Warranty period 64
7.5 Warranty exclusions 65
7.6 Defect remediation-/repairs 66
7.7 Extension of warranty 66
7.8 Spare parts 66
7.9 Liability 66
7.10 Note 67
8. For your information 67
9. Commissioning log 68
- 4 -

- 5 -
1. General information
Before assembling and installing the H2O fireplace insert you should
meet with the master chimney sweep responsible for such matters in
your area. He will advise you on the building regulations and suitability of
your chimney and will carry out the acceptance test on your fireplace
insert. The chimney calculation is based on DIN EN 13384 using the value
specifications table contained in this manual (see Specification 1.2)
(DECLARATION OF PERFORMANCE MAY BE VIEWED AND IS
AVAILABLE FROM WWW.SPARTHERM.COM)
Young children, the elderly and the frail, and pets: as with all heating
devices, a guard should be fitted to protect the above because both the
glass door and the fireplace covering can become very hot.
→Risk of burns! ←
Never leave a fireplace unsupervised when the fire is burning or when it
has just gone out. Do not leave the fireplace unattended for prolonged
periods of time.
CAUTION:
The protective glove supplied is designed only for
protection from heat when operating the control handle and the
cold hand. The glove is not fireproof.
When assembling and operating your fireplace insert and when connect-
ing it to the chimney you must ensure that you comply with national and
European standards, the relevant country-specific and local guidelines
and regulations, and in particular, in Germany, the relevant Heating
Regulation (FeuVO) of the state where you live.
To make better utilisation of the high flue gas temperatures, a water heat
exchanger is integrated in the linings and in the flue gas collector. A hot
water storage tank or buffer storage tank, etc., can be heated with the hot
water generated. If these or similar system components are not available
then other structural measures must be taken to ensure safe, constant
heat dissipation.
Generally speaking, the fireplace must be used with a door that closes
automatically. No modifications to the closing device are permitted. No
additional heat exchangers, supplementary heating surfaces, etc, which
- 6 -
extract heat from the flue gas, may be incorporated into the connecting
pipe to the chimney.
The H2O fireplace insert is intended as an auxiliary heat generator for
water heating systems in accordance with DIN EN 12828, since the
nominal heat output is only maintained as long as the fireplace insert is
stoked to its nominal heat output.
The fireplace may only be used with suitable combustion control systems
adjusted as appropriate. Please consult Spartherm Feuerungstechnik
GmbH as necessary.
Never use the H2O fireplace insert without water.
1.1. Scope of supply
H2O fireplace insert with the following characteristics:
Fireplace insert with integrated water heat exchanger, vertical sliding
door or hinged door.
Safety heat exchanger and bleed valve(s)
¾” overheat discharge valve with ½” immersion sleeve and 4 m length
of capillary tubing, e.g., SYR 3065 (Mini Z1 H2O /XL, Varia 1V H2O and
Varia 1V H2O XL/XLL)
¾” overheat discharge valve with ½” immersion sleeve and 4 m
length of capillary tubing, e.g., Watts TST 2005 (Varia 2/L/2R H2O)
¾” overheat discharge valve with ½” immersion sleeve and 2 m length
of capillary tubing, e.g., Watts (Varia Ah H2O and Varia A-FDh H2O)
Immersion sleeve for the thermostat switch
50 mm x 30 mm cleaning brush
Flue gas connection (swivel)
Thermostat switch for circulating pump, including capillary tubing
(length = 1.5 m): JUMO, heatTHERM 602030 type
Housing thermostat for circulating pump with capillary tubing (length =
2.0 m): Afriso GTK7/HK with 3.0 m of temperature-resistant connecting
cable (Varia 2Lh / 2Rh H2O, Varia Ah H2O and Varia A-FDh H2O)
The following components are available as an option:
Load unit (ESBE, LTC 141 type)
Accessories for the heating installations, e.g., safety valves, expansion
vessels, pressure gauges, etc.
S-Thermatik, combustion control system with temperature display,
e.g., for the buffer storage tank temperature
S-Thermatik, combustion controller allowing variable settings and up to
five temperature indications.

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1.2. Specification
Mini Z1 H2O Mini Z1 H2O
XL
Varia 1V H2O
Varia 1V H2O
XL
Varia 1V H2O
XXL
Varia 2L/2R
H2O
Varia
Ah H2O
Varia
A-FDh H2O
Unit
permissible
working
overpressure
3,0 bar
Max. permissible
feed tempera-
ture1
105 °C
Max. operating
temperature 95 °C
Minimum feed
temperature. 62 °C
Minimum return
temperature 50 >80 >60 °C
Water flow
resistance
at 20 K
temperature
difference between
feed and return
at 10 K
temperature
difference between
feed and return
at 5 K temperature
difference between
feed and return
ap-
prox.
7
18
29
ap-
prox.
7
18
29
ap-
prox.
3
8
30
ap-
prox.
9
20
30
ap-
prox.
9
20
30
ap-
prox.
12
21
34
ap-
prox.
15
32
47
ap-
prox.
15
32
47
mbar
Minimum heating
water flow rate 500 800 900 950 950 900 800 800 l/h
Minimum flow
rate for overheat
disharge valve
900 l/h
Water capacity 25 25 16 46 46 41 32 32 L
- 8 -
Mini Z1 H2O
Mini Z1/Z1h
H2O XL
Varia 1V/1Vh
H2O
Varia 1V/1Vh
H2O XL
Varia 1V/1Vh
H2O XXL
Varia 2Lh/
2Rh H2O
Varia
Ah H2O
Varia
A-FDh H2O
Unit
Weight (empty,
without
accessories)
235 235 245 330 350 380 395 396 kg
Nominal output
range
4,9
–
9,1
7
–
13
7,7
–
14,3
10
–
18,7
14,8
–
27,5
10,3
–
19
7,3
–
13,5
7,3
–
13,5
kW
Nominal heat
output 7,0 11,0 14,4 21,2 14,7 10,4 10,4 kW
Quantity of wood
added per hour 2 2,9 3,7 4,2 5,8 5,7 2,8 2,8 kg/h
Water heating 5,5 8,0 5,5 10,0 15,5 8,4 7,7 7,3 kW
Proportion of
water * 78 80 50 69 73 58 74 70 %
Average flue gas
temperature * 235 245 280 207 173 264 210 210 °C
Minimum
required
manometric
pressure **
12 Pa
Flue gas mass flow 6 7,5 9,6 15,0 19,0 12,2 8 12,2 g/s
Feed connection ¾ ¾ ¾ 1 ½ 1 ½ 1 ¾ ¾ “IG
Return
connection ¾ ¾ ¾ 1 ½ 1 ½ 1 ¾ ¾ “IG
Safety heat
exchanger –
supply pipe
½“
IG
½“
AG
½“
AG
½“
AG
½“
AG
½“
AG
½“ ½“ –
Safety heat
exchanger -
discharge
½“
IG
½“
AG
½“
AG
½“
AG
½“
AG
½“
AG
½“
AG
½“
AG
–
1The overheat discharge valve incorporated in the heating system will
open the cold water feed at a flow temperature of approx. 95°C.
* The values shown represent the mean over a combustion period. These values apply
under test conditions at nominal heat output, burning approx. 2.9 kg dry beech wood per
hour.
** Higher draughts should be reduced to less than 30 Pa by appropriate measures, such as a
secondary air device or air regulator.
10,0

- 9 -
Mini Z1 H2O Fi
g
. 1a
- 10 -
Mini Z1 H2O XL Fi
g
. 1b

- 11 -
Mini Z1h H2O XL Fi
g
. 1c
- 12 -
Varia 1V H2O Fi
g
. 1d

- 13 -
Varia 1Vh H2O Fi
g
. 1e
- 14 -
Varia 1V H2O XL Fi
g
. 1f

- 15 -
Varia 1Vh H2O XL Fig. 1g
- 16 -
Varia 1V H2O XXL Fi
g
. 1h

- 17 -
Varia 1Vh H2O XXL Fi
g
. 1i
- 18 -
Varia 2Lh / 2Rh H2O Fig. 1j

- 19 -
Varia Ah H2O Fi
g
. 1k
- 20 -
1 Abgaskuppel
2separater Verbrennungsluftstutzen Ø150 mm
3 Luftstellhebel
4 Tür klappbar
5 Tür hochschiebbar
Varia A-FDh H2O Fi
g
. 1l

- 21 -
Heat insulating material thicknesses (according to AGI-Q 132).
Further information on the heat insulating material thicknesses and
materials is provided in the installation manual for fireplace inserts.
Rear ventilation dimensions between hearth and heat insulation: The
rear ventilation dimension between the outer edge of the hearth insulation
and the heat insulation of the heat chamber must be at least 30 mm and in
the Varia Ah H2O and Varia A-FDh H2O it must be at least 60 mm.
Base Mounting wall
(side / rear) Ceiling
Mini Z1 H2O,
Mini Z1 H2O XL and
Mini Z1h H2O XL
70 mm 103 mm ---
Varia 1V / 1Vh H2O 55 mm 80 mm ---
Varia 1V / 1Vh H2O XL
Varia 1V / 1Vh H2O XXL 80 mm 100 mm 80 mm
Varia 2Lh / 2Rh H2O 0 mm 52 mm 60 mm
Varia Ah H2O 0 mm 75 mm 0 mm
Varia A-FDh H2O 0 mm 86 mm 0 mm
- 22 -
2.Installation
Generally speaking, the water-heating components and the requisite
safety devices, etc., must be installed by a specialist company. The
H2O fireplace insert must be installed in such a manner that all the
components, including those behind the fireplace lining, are
accessible and available for inspection at all times. After erection
and connection of all services, and before mounting the heat
chamber, the fireplace insert and associated heating installations
must be checked for leaks by means of a pressure test.
For this purpose the H2O fireplace insert must be aligned horizontally by
adjusting the height of the fireplace insert feet, or provided with a slight
upward gradient to the bleed plug at the front.
The H2O fireplace insert must be installed in accordance with the
installation manual for fireplace inserts.
2.1. Basic installation requirements
The H2O fireplace insert may only be installed in thermostatically
protected systems in accordance with DIN 4751 or DIN EN 12828. All
connections to the heating system must, generally speaking, allow of
being detached (e.g. in the form of a threaded connection). Only tempera-
ture-resistant pipes may be used inside the fireplace lining. When sealing
materials are used, you must ensure that they are sufficiently resistant to
the temperatures involved. Because of the position of the feed connection
and the temperature sensors in the front area of the fireplace insert, an
opening must be provided in the front of the heat chamber.
All safety devices must be installed in the “cold” area, or outside of the
fireplace cover. The temperature resistance of the safety devices is not
generally sufficient to allow their installation inside the fireplace cover.
All water-carrying components must be protected against frost.
During installation, always follow the installation and operating manuals
for any additional components fitted.

- 23 -
No claim is made as to the completeness of this list of regulations.
Fireplaces should only be installed in rooms and at locations where the
position, structural conditions and type of use will not create any hazards.
The floor area of the room where the fireplace is installed must be of such
a type and size that the fireplace can be correctly operated.
During installation, connection and operation of the H2O fireplace insert,
always follow and apply all the requisite national and European
standards and local regulations (DIN, DIN EN, regional building
regulations, German state heating regulations, etc.).
HeizAnlV: German Heating Systems Regulation
FeuVo: (German State heating Regulation) Heating
Regulation of the relevant German state
1. BlmschV
(German Emissions Regulation)
First Decree enacting ther German Federal
Emissions Protection Act
EnEV German Energy Saving Regulation
TROL Technical Rules of the Tiled Stove and Air
Heating Building Trade (ZVSHK)
DIN 1298 /
EN 1856: Connecting pieces for firing systems
DIN EN 13229 Fireplace
inserts, including open fireplaces, for solid fuels
DIN EN 50165
Electrical equipment of non-electrical devices
for domestic use and similar purposes – Safety
requirements
DIN EN 13384 Calculation procedure for flue gas systems
DIN 18160-1/2 Flue gas systems / domestic chimneys
DIN EN 12828 /
DIN 4751
Heating systems in buildings
Planning of hot water installations
LBO The building regulations of the German state in
question
VDI 2035 Water conditioning for heating systems
- 24 -
2.2. Electrical connection
Full electrical installation of the individual components of the heating
system may only be carried out by an authorised specialist company. All
the work must be carried out according to the VDE Regulations (e.g. VDE
0105, VDE 0116, VDE 0100 etc.) and the technical connection require-
ments of the local power supply company.
2.3. H2O fireplace insert connections
The connections for the safety heat exchanger, the return and the rear
bleed valve are located on the rear and can always be accessed through
an inspection opening (see Fig. 2a-2f) via the combustion chamber. The
connections for the feed, the front bleed valve and the immersion sleeves
for the temperature sensors are all located at the side on the flue gas
collector (see Fig. Fig. 2a-2f).
These require an opening to be provided in the fireplace cover to obtain
access. For transport purposes the connections are provided with
transport protection devices, which must be removed during installation.
The connections are clearly marked and must not be used for any other
purpose. Equally, the integrated safety device (safety heat exchanger)
must not be used for heating water. We recommend the use of straight or
angled radiator screw connections for the pipe connections.
If the protective anode (only Varia H2O XL and XXL) is installed in open
heating systems, make sure it is accessible so that it can be easily
replaced. The length of the anode must not exceed 30 cm (folding insert)
from the first thread.
When installing the Varia Ah H2O / A-FDh H2O in an existing heating
system we recommend a minimum nominal pipe width for heating pipes
of: copper pipe, min. 28 x1.0 mm or steel pipe, min. 1” (DN25, 33.7 x
3.25 mm). Plastic pipes or composite pipes must not be used inside the
heat chamber. If ‘temperature-resistant’ gaskets (>140°C) are used on
metal pipes (press systems), these pipes must not be fitted within the
radiant area of components carrying flue gas (distance of 200 mm). As a
general rule, though, after dimensioning they should be connected up by a
specialist company.

- 25 -
Mini Z1 H2O, Mini Z1 H2O XL, Mini Z1h H2O XL
An inspection opening in the
rear wall can be opened for
access to the water connec-
tions of the Mini Z1 H2O, Mini
Z1 H2O XL, Mini Z1h H2O XL
fireplace insert. The combus-
tion chamber lining (side walls,
rear wall, ash grill, ash pot and
combustion chamber floor)
must be removed for this
purpose.
A A immersion sleeve of pump thermostat
B front bleed valve
C immersion sleeve for overheat discharge valve
D ¾” feed
E rear view
F ½” ‘discharge’of overheat discharge valve
G ½” ‘feed’ of overheat discharge valve
H rear bleed valve
I ¾“ return
J inspection opening
Fi
g
. 2a
- 26 -
Varia 1V H2O, Varia 1Vh H2O
To facilitate access to the water connections of the Varia 1V H2O, an
inspection opening in the rear wall can be opened. The rear wall of the
combustion chamber lining must be removed for this purpose. The sealing
panel in the rear wall can then be unscrewed and removed (see Fig. 2b).
The connections can then be examined.
After the inspection the sealing panel must be screwed back in place and
the combustion chamber lining reassembled.
A ¾” feed
B ½” ‘discharge’of overheat discharge valve
C ½” ‘feed’ of overheat discharge valve
D filling and drain fittings DN 15 (1/2”) optional
E ¾” return
Fi
g
. 2b

- 27 -
Varia 1V H2O XL, Varia 1Vh H2O XL,
Varia 1V H2O XXL, Varia 1Vh H2O XXL
For access to the water
connections of the Varia 1V
H2O XL an inspection
opening in the rear wall can
be opened (see Fig. 2c).
The combustion chamber
lining (side walls, rear wall,
ash grill, ash pot and
combustion chamber floor)
must be removed for this
purpose. After the inspection
the sealing panel must be
screwed back in place and
the combustion chamber
lining reassembled and the
combustion chamber lining
installed.
Access to the feed connec-
tion and the front bleed valve
must be provided through an
opening in the heat chamber
wall.
A 1 1/2” feed“
B bleed valve
C Immersion sleeves for thermal sensor
D bleed valve
E ¾” return
F ½” ‘feed’ of overheat discharge valve
G ½” ‘discharge’ of overheat discharge valve
Fi
g
. 2c
- 28 -
Varia 2Lh/2Rh H2O
For access to the water
connections of the Varia
2Lh/2Rh H2O an inspection
opening in the rear wall can
be opened. The combus-
tion chamber lining (side
walls, rear wall, ash grill,
ash pot and combustion
chamber floor) must be
removed for this purpose.
After the inspection, the
sealing panel should be
screwed back in place and
the combustion chamber
lining installed.
Access to the feed
connection and front bleed
valve must be provided
through an opening in the
heat chamber wall.
A bleed valve
B 1” IG feed“
C ½” IG immersion sleeve for overheat discharge valve
D ½” IG immersion sleeve for pump thermostat
E 1” IG return connection
F lower bleed valve
G ½” AG ‘discharge’of overheat discharge valve
H ½” AG ‘feed’ of overheat discharge valve
Fi
g
. 2d

- 29 -
Varia Ah H2O und Varia A-FDh H2O
For access to the water connections of the Varia Ah H2O / A-FDh H2O an
opening has to be made in the fireplace cover. The deflector plate must
rest against the side wall of the combustion chamber (see Fig. 2e).
Varia Ah H2O
The connections for the safety heat exchanger are located at the bottom
on the right-hand side. The feed and return, vent and temperature sensor
connections are located at the top and bottom on both sides (see Fig. 2f).
An opening must be made in the fireplace cover for access to the
connections and immersion sleeves (see Fig. 2e). The connections are
fitted with plastic caps for protection during transport. These caps must
be removed during installation and replaced by suitable, permanent-
ly tight plugs. The connections are clearly marked and must not be used
for any other purpose. The integral safety device (safety heat exchanger)
must not be used to heat water. We recommend the use of straight or
angled radiator screw connections for the pipe connections.
1 Deflector
plate
(optional)
2 Baffle
Fi
g
. 2e
- 30 -
1 Feed 3/4"
2 Return 3/4"
3 Temperature sensor for overheat discharge valve 1/2"
4 Temperature sensor for thermostat switch 1/2"
5 Thermal safety heat exchanger outlet 1/2"
6 Thermal safety heat exchanger inlet 1/2"
7 Vent 3/8"
Varia A-FDh H2O
The connections for the safety heat exchanger are located at the bottom
on the right-hand side. The feed and return, vent and temperature sensor
connections are located at the top and bottom on both sides (see Fig. 2g).
An opening must be made in the fireplace cover for access to the
connections and immersion sleeves (see Fig. 2e). The connections are
fitted with plastic caps for protection during transport. These caps must
Fi
g
. 2f

- 31 -
be removed during installation and replaced by suitable, permanent-
ly tight plugs. The connections are clearly marked and must not be used
for any other purpose. The integral safety device (safety heat exchanger)
must not be used to heat water. We recommend the use of straight or
angled radiator screw connections for the pipe connections.
1 Feed 3/4"
2 Return 3/4"
3 Temperature sensor for overheat discharge valve 1/2"
4 Temperature sensor for thermostat switch 1/2"
5 Thermal safety heat exchanger outlet 1/2"
6 Thermal safety heat exchanger inlet 1/2"
7 Vent 3/8"
Note on all fireplace inserts:
Operation without a combustion chamber lining is not permitted
Fi
g
. 2
g
- 32 -
2.4. Minimum crosssections for convection air
The minimum cross-sections for the convection air (supply air and
circulating air) in the lining or heat chamber must be executed as follows.
Hot air: Cold air:
Mini Z1 H2O
Mini Z1 H2O XL
Mini Z1h H2O XL
500 cm² 500 cm²
Varia 1V H2O
Varia 1Vh H2O
Varia 1V H2O XL
Varia 1Vh H2O XL
Varia 1V H2O XXL
Varia 1Vh H2O XXL
600 cm² 750 cm²
Varia 2Lh / 2Rh H2O 600 cm² 750 cm²
Varia Ah H2O 440 cm 400 cm²
Varia A-FDh H2O 220 cm² 200 cm²
Generally speaking, the Technical Rules of the Tiled Oven and Air
Heating Building Trade (TR-OL 2006) must be followed.
2.5. Bleeding
Two bleed valves are available for bleeding the water heat exchanger. For
the Varia 1V/1Vh H2O, only one bleed valve is provided, on the upper heat
exchanger, and on the Varia Ah H2O and Varia A-FDh H2O the bleed
valve is located at the top left and right. Firstly, the upper bleed valve (in
the area of the flue gas collector) can be used. This requires that a
sufficiently large opening be provided in the lining in the immediate
vicinity. Secondly, the lower bleed valve (in the area of the connections on
the rear) can be accessed through the inspection opening in the combus-
tion chamber and this can be used. After commissioning, the insert must
be bled several times because the heating water emits gases due to the
high temperatures.
For the Varia 1V H2O, a vent pipe fitted to the rear wall is available (see
Fig. 3).

- 33 -
For this version the following additional information must be borne in mind
when performing installation.
The TROL guidelines
regarding the free cross-
section of the vent openings
and the maximum supply air
temperatures of 75°C must
always be followed.
Lockable circulating and
supply air openings are not
recommended. This is to
ensure that no heat
accumulates inside the
heating chamber. (Fig. 3)
If the vent pipe has been
dismantled on the installa-
tion site to transport it, for
example, make sure that for
subsequent assembly the
copper pipe in the lower
area rests fully against the
copper rail and the body. The tightness of the screw connection on the
head section and correct seating of the heat insulation must then be
checked.
A Temperature sensor for the ½” thermostat switch and ½” overheat
discharge valve
B Vent pipe with isulation
C Vent pipe with copper rail
D filling and drain fittings DN 15 (1/2”) optional
Fi
g
. 3
- 34 -
2.6. Safety valve
A component-tested safety valve (e.g., Syr type 1915), with a maximum
response overpressure of 3.0 bar must be installed in the feed pipe in
the immediate vicinity of the H2O fireplace insert. During installation,
attention must be paid to the manufacturer’s specifications (including
ambient temperature) for the safety valve. A shutoff device must not be
incorporated in the system between the safety valve and the H2O fireplace
insert as it could prevent the safety device from operating. Furthermore,
all the required safety devices must be integrated throughout the system
in such a manner as to ensure non-hazardous operation. A separate
safety valve must still be fitted, even if there is one elsewhere in the
system (make sure you comply with TRD 721).
2.7. Load unit
Generally speaking, the H2O fireplace insert may only be operated with a
suitable load unit. During operation the return temperature must be at
least 55°C. On the Varia Ah H2O and Varia A-FDh H2O the return
temperature must be at least 60°C.
To ensure this temperature is achieved, a circulating pump must be
installed in such a manner that it does not cut in until a water temperature
of 60-65°C has been reached in the heat exchanger. This must be
implemented using the pump thermostat (supplied, e.g., JUMO
heatTHERM or Afriso) (see section 3.9).
To avoid dropping below local dew points and resulting deposits on the
water heat exchanger, a regulated load unit must generally be installed.
The longer the pipe run between the load unit and the fireplace insert, the
longer the temperature in the fireplace insert remains below the dew point,
as the heating water first has to be heated when the system is fired up.
We therefore recommend fitting the load unit in the immediate vicinity of
the fireplace insert, ensuring it is readily accessible.
Please note: If there is no load unit fitted or it is not operating properly,
we cannot accept claims under warranty or general liabil-
ity for operating faults or corrosion damage (soot build-
up, deposits, etc.) on the water heat exchanger or on the
chimney, etc.

- 35 -
2.8. Overheat discharge valve
Since the heating for the H2O fireplace insert is not automatic and cannot
be quickly switched off, the hot water attachment must be equipped with
an overheat discharge valve in accordance with DIN 4751 – Part 2 or DIN
EN 12828 to prevent hazardous situations in the event of a fault, e.g., a
power failure. A safety device is installed for this purpose in the H2O
fireplace insert (safety heat exchanger) to protect against overheating.
This safety device must not be used as a water heater.
The overheat discharge valve supplied (e.g., SYR, type 3065) is tested
and approved for a minimum water flow rate of 900 kg/h. The sensor on
the capillary tubing must be inserted and permanently fixed in the
connection opening of the H2O fireplace insert (in the sealed-in immersion
sleeve) that is marked accordingly.
The following points must always be observed during installation to
ensure the safety device can work properly:
During installation the enclosed installation and operating manual
supplied by the overheat discharge valve manufacturer must be fol-
lowed!
The fittings of the overheat discharge valve may only be installed in
the feed pipe. This is to ensure that there is no standing water in the
safety heat exchanger when used as intended.
The fittings of the overheat discharge valve must not be sited in the
hot area of the heat chamber (convection chamber) of the fireplace
system (max. ambient temperature 80°C). Select the position on the
basis of the length of the capillary tubing.
A minimum flow pressure of 2.0 bar must be available at the cold
water intake. This pressure must be maintained at all times. Fluctua-
tions in water system pressure must not occur. This means, for ex-
ample, that supply from a domestic water system that is itself de-
pendent on the mains supply is not permitted.
A minimum water flow rate of approx. 900 kg/h must be ensured. It
must not be possible to shut off this supply pipe.
The heating insert must be aligned so that the front bleed valve is at
the highest point.
All safety-relevant components must be integrated in the system in such a
manner that checks may be carried out on their operation and for possible
leaks at any time. The discharge of the overheat discharge valve must be
executed in such a manner that a test may be carried out at any time (e.g.
via an outlet with siphon).
- 36 -
2.9. Thermal pump control system
The fireplace insert must always be used with a load unit. A JUMO or
Afriso thermostat switch is also supplied with the cell. This must be
electrically integrated into the power supply of the load unit (circulating
pump).
The appropriate rolled-up capillary tube should be unrolled and inserted
into the marked immersion sleeve at the top front right/left and secured
with the clip supplied. Ensure there are no kinks in the capillary tube!
This switch ensures that the circulating pump only cuts in if the water
temperature is adequate and is switched off again if the temperature
drops below the specified level. The connection is made as shown in Fig.
4a-b. Control of the circulating pump by means of a boiler control system
or similar device is not recommended. During installation the enclosed
installation and operating manual for the thermostat must be followed. The
thermostat sensor must be inserted and permanently fixed in the
connection opening of the H2O fireplace insert (sealed immersion sleeve)
that is marked accordingly.
The maximum loading capacity of the thermal pump control system is
approx. 500 W at 230 V AC.
The factory setting of the minimum thermostat can be adjusted by means
of the control dial and has been preset to a range of approx. 62°C to
approx. 72°C. The start-up temperature of the pump is set on this
thermostat. Optionally, if conditions so warrant, the setting range can be
adjusted by the company performing installation. If the control dial is
removed, the setting range can be varied by moving the locking disc,
which can be reseated in a different position by removing the screws. In
the minimum setting (the locking disc is fastened through the holes
marked “min”), the setting range can be adjusted from approx. 57°C to
approx. 67°C.
Please note: The minimum setting of approx. 57°C may result in values
below the dew point. The maximum setting (locking disc fastened through
the holes marked “max.”) ranges from 67°C to 77°C.
The JUMO heatTHERM fittings must not be sited in the hot area of the
heat chamber (convection chamber) of the fireplace (max. ambient
temperature 80°C). Select the position in the cold area on the basis of the
capillary tubing length!

- 37 -
The connection is made as shown in Fig. 4a and 4b.
Fi
g
. 4b
Fi
g
. 4a
- 38 -
1 The blue wire is the connected phase (L`) and is phase wired to the
circulating pump or load unit.
2 The green-and-yellow wire is wired to the protective conductor
(earth) (PE) of the mains supply.
3 The brown wire is wired to phase (L) of the mains supply.
4 Thermostat pump control electrical connection
5 Pump control thermostat (e.g. Afriso), with approx. 3.0 m connecting
cable 2x0.75 mm2
6 Return temperature indication (circulating pump)
7 Terminal 1 not needed
8 Phase (L) brown wire
9 Connected phase (L`) blue wire
2.10. Incorporation into a heating system
Please note: The H2O fireplace insert may only be installed in a complete
system after detailed planning for the entire heating system according to
relevant best industry practice and safety standards.
The correct dimensioning of the pumps, fittings, pipework, buffer storage
tank and safety components, such as the safety valve and expansion
vessel, is the responsibility of the design office and/or of the company
carrying out installation.
Note that very high water outputs of approx. 20 kW can occur briefly
during the combustion phase. The heating system should be dimensioned
to take account of this.
The following calculation example may be helpful for dimensioning the
buffer storage tank:

- 39 -
kJQ
Kkg
Kkg
kJ
,Q
Δtm
p
cQ
37683
303001874







For the Mini Z1 H2O:
The following assumptions were made in this case:
Buffer storage tank size: 300 litres (approx. 300 kg of water)
Water temperature in the storage tank initially: 30°C
Final water temperature in the storage tank: 60°C
Temperature difference 30°C (equivalent to 30 K)
No heat extracted from the storage tank during heating by the Mini
Z1 H2O, and no heat losses from the system
This means that a theoretical heat quantity of 37,683 kJ (= 37,683 kWs)
is required to heat 300 litres of water in a storage tank from an assumed
30°C to 60°C (without accounting for any losses or heat extraction from
the system). This heat quantity is equivalent to approx. 10.5 kWh.
However, if the heating system is suitably constructed, e.g., in the form of
a stratified storage tank, heat utilisation can commence shortly after
circulation starts in the Mini Z1 H2O. In such a case, only the excess
energy not required for heating is stored in the buffer storage tank.
Assuming, on average, output of approx. 5.5 kW from the H2O fireplace
insert, heating of the entire storage tank takes just under 2 hours.
On very cold winter days the fireplace system may be in operation for as
much as 12 hours or so. The thermal energy produced in such a case is
then theoretically equivalent to 66 kWh. This thermal energy would then
be sufficient to heat just under 1,900 litres of water (from 30°C to 60°C).
However, heat is generally always extracted in such a situation so that
there should be no overloading of the buffer storage tank (> 90°C).
The assumptions, values and results for the other fireplace insert are
listed below in the table:
- 40 -
Varia A-FDh H
2
O
500 Liter
20 kW
7,3 kW
~2,5h
85 kW
2400 Liter
Varia Ah H
2
O
500 Liter
20 kW
7,3 kW
~2,5h
85 kW
2400 Liter
Varia 2Lh/2Rh H
2
O
500 Liter
17,4 kW
8,4 kW
~2h
101 kW
2900 Liter
Varia 1V/1Vh H
2
O
XXL
1000 Liter
35 kW
15,5 kW
~2h
186 kW
5400 Liter
Varia 1V/1Vh H
2
O XL
750 Liter
26,2 kW
10 kW
~3h
120 kW
3400 Liter
Varia 1V/1Vh H
2
O
300 Liter
10,5 kW
5,5 kW
~2h
66 kW
1900 Liter
Mini Z1/Z1h H
2
O XL
500 Liter
17,4 kW
8 kW
~2h
96 kW
2750 Liter
Mini Z1 H
2
O
300 Liter
10,5 kW
5,5 kW
~2h
66 kW
1900 Liter
Pufferspeichervolumen
Notwendige Wärmemenge zur
Erwärmung des
ufferspeichers
Durchschnittliche
angenommene
Wasserleistung
Zeit zur Erwärmung des
Pufferspeichers (bei 30K)
Wärmeenergie in 12h
Wärmemenge ausreichend für