Dražice OKCE 80, OKC 100, OKC 100/1m2, OKC 125, OKC 125/1m2 Operation And Installation Manual

Operation and Installation Manual

TANK-TYPE WATER HEATERS FOR VERTICAL

MOUNTING

Combined Electric

OKCE 50
OKC 80 OKCE 80
OKC 100 OKC 100/1m2 OKCE 100
OKC 125 OKC 125/1m2 OKCE 125
OKC 160 OKC 160/1m2 OKCE 160
OKC 180 OKC 180/1m2 OKCE 180
OKC 200 OKC 200/1m2 OKCE 200

Družstevní závody Dražice – strojírna s.r.o.

Dražice 69

294 71 Benátky nad Jizerou

Tel.: [phone], fax: [phone]

www.dzd.cz
[e-mail]

2

Read carefully the below instructions prior to the installation of the
heater!

Dear Customer,

The Works Cooperative of Dražice – Machine Plant, Ltd., would like to thank you for your decision to use a
product of our brand.

The manufacturer reserves the right for engineering modification of the product.
The product is designed for permanent contact with drinkable water.

Guide Contents

1. FUNCTION DESCRIPTION ............................................................................................................... 2

2. MESSAGE FOR CUSTOMERS .......................................................................................................... 3

3. TECHNICAL DESCRIPTION ............................................................................................................. 3

4. OPERATING ACTIVITY .................................................................................................................... 3

5. SERVICING ......................................................................................................................................... 4

6. WALL MOUNTING ............................................................................................................................ 5

7. PLUMBING FIXTURE........................................................................................................................ 5

8. CONNECTION OF COMBINED HEATER TO HOT WATER HEATING SYSTEM ..................... 6

9. ELECTRIC INSTALLATION ............................................................................................................. 6

10. PUTTING THE HEATER INTO OPERATION ................................................................................. 6

11. HEATER CLEANING AND ANODE ROD EXCHANGE ................................................................ 6

12. IMPORTANT NOTICES ..................................................................................................................... 6

13. FIRE-FIGHTING REGULATIONS FOR INSTALLATION AND USE OF HEATER .................... 7

14. INSTALLATION REGULATIONS .................................................................................................... 7

15. MOST FREQUENT FUNCTION FAILURES AND THEIR CAUSES ............................................. 8

16. PRODUCT ACCESSORIES ................................................................................................................ 8

17. TECHNICAL DATA CHART.............................................................................................................9

18. PICTURES.......................................................................................................................................................10

Environment Type:

It is recommended to use the product in indoor environment with air temperatures from +2°C to 45°C and a
relative humidity up to 80%.

1. FUNCTION DESCRIPTION

The heater is designed for accumulation heating of service water using electricity or thermal energy via an

exchanger (for the combined design only).
Water is heated by an electric element (or a heat exchanger) in an enamelled thermally insulated accumulator at
the time defined by the power supplier. The element is at the time of heating controlled by a thermostat the
temperature of which can be adjusted continuously (within the range between 5°C and 74°C). Once the selected
temperature is reached, heating interrupts automatically. Water accumulated in the tank is then used for
consumption. The tank keeps constant pressure of water from the water main. If the combination faucet hot water
valve is opened, water from the water supply conduit pressed out by cold water pressure flows out of the heater.
Hot water flows out through the top part, and water flowing in remains in the bottom part of the heater. Pressure
principle allows hot water withdrawal at any place from the heater (Fig. 1).

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2. MESSAGE FOR CUSTOMERS

Hot water consumption

Consumption of hot water in households depends on the number of people, amount of sanitary equipment, length,
diameter and insulation of piping in the flat, or on individual habits of users.
The cheapest option of water heating comes at the time when the electricity rate is reduced. Find out in what time
intervals your electricity supplier provides reduced tariff and, depending on that information, select relevant
volume and power input of the heater so that your hot water consumption covered the needs of your household.

Energy saving

Hot utility water reservoir is insulated by means of a top-quality polyurethane foam with zero CFCs content.
Adjust the temperature of the heater's thermostat to that level only that you need to run your home. Thus you will
reduce electricity consumption, as well as the amount of lime sediments on the walls of the receptacle and on the
electric element's pit.

Emergency power consumption

If no heated water is taken from the tank, a small amount of heat leaks. This loss is measured for a period of 24
hours at the temperature of 65°C in the heater, and at 20°C in its ambient area. The resulting value is expressed in
kWh/24h and indicates the amount of power needed to maintain the set temperature.

Data sheet pursuant to Directive No 442/2004 and Appendix No 7

3. TECHNICAL DESCRIPTION

The heater tank is made of a steel plate and tested by 0.9 MPa overpressure. The inside of the receptacle is

enamelled. A flange is welded onto the bottom of the tank with a flange lid screwed to it. A sealing ring is inserted
between the flange lid and the flange.
Thermowells for placing a heating element and sensors of regulation thermostat and safety fuse are located
in the flange lid. Anode rod is mounted on M8 nut. The water reservoir is insulated by means of polyurethane
foam. Electric wiring is placed underneath the plastic removable cover. The temperature of water can be set using
the thermostat.
In combined versions, a heat exchanger is welded in the pressure tank. The heat exchanger is only intended
for the heating circuit.

4. OPERATING ACTIVITY

a) Water heating by electric energy

After the heater is connected to electric network, the heating element starts heating water. The element is

turned on and off by a thermostat. After reaching the temperature set, the thermostat switches off the electric circuit

OKC 80 C 8,9 75 2,5 4,8 0,71
OKC 100; OKC 100 /1m2 C 8,8 95 3 6 0,88
OKC 125; OKC 125 /1m2 C 8,7 120 3,8 8 1,09
OKC 160; OKC 160 /1m2 C 8,7 147 5 9,6 1,33
OKC 180; OKC 180 /1m2 C 7,7 175 5 10,6 1,39
OKC 200; OKC 200 /1m2 B 7 195 5,5 12 1,4
OKCE 50 C 9 51 1,5 3 0,45
OKCE 80 C 8,9 80 2,5 4,8 0,71
OKCE 100 C 8,8 100 3 6 0,88
OKCE 125 C 8,7 125 3,8 8 1,09
OKCE 160 C 8,7 152 5 9,5 1,33
OKCE 180 C 7,7 180 5 10,6 1,39
OKCE 200

B 7 200 5,5 12 1,4

Heat losses

kWh/24hr

Time of content

heating (hours)

Electricity consumption

for heating of the

contents from 15°C to

65°C in kWh

Heater types

Energy

efficiency

class

Heat

losses

Wh/24hr/l

Nominal

capacity (l)

4

and thus discontinues water heating. The control light signals if the element is in operation (light is on) or if it is off
(the light goes out). In case of longer operation without using the heated volume, the thermostat has to be set to

position 5°C to 8°C (set the “snowflake” symbol on the thermostat selector) to avoid its freezing, or electricity

supply to the heater has to be switched off.
In combined versions, the stop valve on the inlet to the exchanger has to be closed, which prevents heating
water in the hot water heating system.

b) Service water heating via thermal energy through heat exchanger

Closing valves of the heat exchanger must be opened which ensures heating water flow from the hot water
heating system. Together with a closing valve, it is recommended to install an air outlet valve at the inlet to the
heat exchanger in order to bleed the heat exchanger (Fig. 2) as needed, in particular before the beginning of the
heating season. The time of heating using the heat exchanger depends on the temperature and flow of water in the
hot water heating system. A combined heater is made in universal design – depending on the need of connecting
the closing valves to the heating element either from the right, or from the left (Fig.2).

5. SERVICING

Service devices of heaters of 50 to 200 l capacity are located under the transparent guard of the control panel.

Thermostat knob Electric circuit closing indicator lamp Tipping transparent guard

Temperature setting

Water temperature is set by turning the thermostat knob. The desired symbol is adjusted against the fixed point on
the control panel.

Notice: Adjusting the thermostat selector at the left backstop does not mean permanent shutoff of the heating
element.
When the heater is in use without blocking the daily rate, we do not recommend the temperature to be set above
60°C.
The maximum value to select is “60“.

Limiting the regulation range; locked settings.

For various safety reasons (unintentional scalding, preventing children or unauthorised person from handling), the
regulation range can be limited, or the setting on the thermostat blocked.
Regulation limited - pull off the thermostat knob (it will be tough at first) and you will find two cylindrical pins

2,15mm on the back side of the knob

- pull off one pin and insert it to the corresponding hole of the selected maximum temperature.

- put the knob back on (to the stop).

Lower temperature range
limit (about 5°C)

Fixed point on the control
panel

Anti-freezing temperature
(about 8°C)

Upper temperature range

limit (about 74°C)

”Ideal” temperature (about
60°C)

5

To block the setting – set the selected temperature by pulling off the thermostat knob without changing the setting

and you will find two pins on the back side of the knob; pull both of them and fit them into
the holes corresponding with the selected temperature so that the gap between the pins was
without a hole, and the position was opposite the set temperature.

6. WALL MOUNTING

Prior to mounting, check the loading capacity of the wall and, depending on the type of masonry, choose a

suitable anchorage material, or reinforce the wall, if needed. The water heater shall only be mounted in vertical
position so that the lower edge of the heater was placed at least 600 mm above the floor (Fig. 4, 5). In combined
heaters, elbows have to be attached to the heating water inlet and outlet and, by turning them, the mounting either
from the right or from the left has to be determined (Fig. 2).
With regard to various types of carrying masonry and broad assortment of special anchorage material
available at the market, we do not provide heaters with this material. The anchorage system has to be selected
individually, depending on the conditions. We recommend an authorised company perform mounting on the

wall and anchorage, or discuss the anchorage with a professional.

7. PLUMBING FIXTURE

Connection of heaters to plumbing fixtures is illustrated on Figures 1 and 2. For potential disconnection of
the heater, the service water inlets and outlets must be provided with screw coupling Js 3/4“. Safety valve is
mounted on the cold water inlet identified with a blue ring.
The heaters must be equipped with a drain valve.
Each hot service water pressure heater must have a membrane spring loaded with a safety valve. The safety valve
must be easily accessible, as close to the heater as possible. The input pipes must have at least the same clearance
as the safety valve. The safety valve is placed high enough to secure dripping water drain by gravity. We
recommend mounting the safety valve onto a branch pipe. This allows easier exchange without having to drain the
water from the heater. Safety valves with fixed pressure settings from the manufacturer are used for the assembly.
Starting pressure of a safety valve must be identical to the maximum allowed heater pressure, and at least 20%
higher than the maximum pressure in the water main. If the water main pressure exceeds such value, a reduction
valve must be added to the system. No stop valves can be put between the heater and the safety valve. During the
assembly, follow the guide provided by the safety equipment manufacturer. It is necessary to check the safety valve
each time before putting it into operation. It is checked by manual moving of the membrane from the seat, turning
the make-and-break device button always to the right. After being turned, the button must click back into a notch.
Proper function of the make-and-break device results in water draining through the safety valve outlet pipe. In
common operation, such a check needs to be implemented at least once a month, and after each heater shutdown
for more than 5 days. Water may be dripping off the drain pipe of the safety valve; the pipe must be open into the
air, pointed down; environment temperatures must not drop below zero.
When draining the heater, use a recommended
drain valve. First, close water input into the
heater.
Find necessary pressure values in the following
table.
For proper safety valve operation, a backflow
valve must be mounted on the inlet pipes,
preventing spontaneous heater draining and hot water penetrating back into the water main.

When assembling the security equipment, follow ČSN 06 0830.

Safety valve

starting pressure

(MPa)

Admissible operating

water heater

pressure (MPa)

Max. pressure in

the cold water pipe

(MPa)

0.6

0.6

up to 0.48

0.7

0.7

up to 0.56

1 1 up to 0.8

Regulation limited

Setting blocked

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8. CONNECTION OF COMBINED HEATER TO HOT WATER HEATING SYSTEM
(Fig. 1, 2)

It is recommended to install stop valves on the heating water inlet and outlet (for possible dismantling of
the heater).
The valves have to be as close to the heater as possible to avoid higher thermal losses.

9. ELECTRIC INSTALLATION

The electric wiring scheme is attached to the water heater on the side of the electric installation guard (see also Fig.

6).

Connection, repairs, and wiring inspections may only be implemented by a company authorised to such activity.
Expert connection must be confirmed on the warranty certificate.
The heater is connected to the 230 V/50 Hz electric network using a fixed moving conductor with a switch that
turns off all network poles and the circuit breaker (protector).
Installations in bathrooms, laundromats, rest rooms, and showers, 33 2000-7-701 must be obeyed.
The degree of protection of electric parts of the heater is IP 45.
Respect the rules of protection against electrical injuries in accordance with ČSN 33 2000–4-41.

10. PUTTING THE HEATER INTO OPERATION

After connecting a heater to the water main, hot water heating system, electric network, and after testing its safety
valve (based on the valve manual attached), the heater may be put into operation.

Procedure:

a) Check both water and electric installation; for combined heaters, check the installation to a hot water

heating system. Check proper placement of operating and safety thermostat sensors. The sensors must be
inserted all the way in; first the operating and then the safety thermostat.

b) Open the hot water valve on the combination faucet;
c) Open the cold water inlet valve to the heater.
d) As soon as the water starts running through the hot water valve, the heater is filled and the valve closes.
e) In case of a leakage (flange lid), we recommend fastening the flange lid bolts and screwing the electric

wiring guard.

f) Fasten the electric installation cover.
g) When heating service water with electric energy, turn the electricity on (in combined versions, the valve on

the heating water inlet into the heating element has to be shut off);

h) When heating service water with thermal energy from a hot water heating system switch electricity off and

open the valves of heating water inlet and outlet, possibly de-aerate the exchanger.

i) When commencing operation, flush the heater until the cloudiness in the water is gone.
j) Make sure to fill in properly the warranty certificate.

11. HEATER CLEANING AND ANODE ROD EXCHANGE

Repetitive water heating causes limestone sediment on both the tank walls and chiefly the flange lid.
The sedimentation depends on the hardness of water heated, its temperature, and amount of hot water consumed.

We recommend checking and cleaning the tank from scale and eventual replacement of the anode rod after
two years of operation. The anode life is theoretically calculated for two years of operation; however, it changes

with water hardness and chemical composition in the place of use. Based on such an inspection, the next term of
anode rod exchange may be determined. Have the company in charge of service affairs clean and exchange the
anode. When draining water from the heater, the combination faucet valve for hot water must be open, preventing
occurrence of under-pressure in the heater tank which would stop the water from draining.

12. IMPORTANT NOTICES

 Without a confirmation of performed electrical installation issued by an authorised company, the

warranty certificate shall be void.

 Check and exchange the Mg anode regularly.
 You have to apply for approval of a local power supplier to connect the heater.
 No stop valves can be put between the heater and the safety valve.

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 If the overpressure in the water main exceeds 0.48 MPa, a pressure control valve must be mounted before the

safety valve.

 All hot water outputs must have a combination faucet.
 Before filling the heater with water for the first time, it is recommended to fasten the flange connection nuts of

the tank.

 It is not allowed to handle the thermostat, aside from temperature resetting with a control button.
 All electric installation handling, adjustment and replacement of the regulation elements shall only be

performed by an authorised service company.

 The thermal fuse must not be turned off! In case of thermostat defect, the thermal fuse interrupts electric

power input to the heating element if the water temperature in the heater exceeds 90 °C.

 As an exception, the thermal fuse may also switch off due to water overheating caused by overheating the hot

water heating system boiler (in case of a combined heater).

 We recommend you operate the heater with one type of energy.

Disposal of packaging material and functionless product

A service fee for providing return and recovery of packaging material has been paid
for the packaging in which the water heater was delivered.
The service fee was paid pursuant to Act No. 477/2001 Coll., as amended, at EKO­KOM a.s. The client number of the company is F06020274. Take the water boiler
packages to a waste disposal place determined by the town. When the operation
terminates, disassemble and transport the discarded and unserviceable heater to a
waste recycling centre (collecting yard), or contact the manufacturer.

13. FIRE-FIGHTING REGULATIONS FOR INSTALLATION AND USE OF HEATER

We would like to emphasise that the heater must not be connected to power supply if work

involving flammable liquids (petrol, spot remover) or gases, etc., is performed nearby.

14. INSTALLATION REGULATIONS

Regulations and instructions that must be obeyed if the heater is connected

a) to the heating system

ČSN 06 0310 – Thermal systems in buildings – Designing and Installation
ČSN 06 0830 – Thermal systems in buildings – Protecting devices for electric network

b) to the electrical network

ČSN 33 2180 - Connecting of electric devices and appliances
ČSN 33 2000-4-41 - Low voltage electric installations Protective measures to ensure safety

- Protection against electric shock

ČSN 33 2000-7-701 - Low voltage electric installations: Single-purpose devices and devices in special

premises

- Premises with tub or shower

c) to the hot water heating system

ČSN 06 0320 - Thermal systems in buildings - Hot water preparation – Design and Project Engineering
ČSN 06 0830 – Thermal systems in buildings – Protecting devices
ČSN 73 6660 – Internal water conduits
ČSN 07 7401 - Water and steam for thermal energy equipments with working steam pressure up to 8 MPa
ČSN 06 1010 - Tank water heaters with water and steam heating; and combined with electric heating.

Technical requirements. Testing.

ČSN 75 5455 – Calculation of water installations inside buildings
ČSN EN 12897 – Water supply – Indirectly heated closed tank-type water heaters

Both electric and water installation must follow and meet requirements and regulations relevant in the
country of use.

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15. MOST FREQUENT FUNCTION FAILURES AND THEIR CAUSES

Water is cold

LED is on

The temperature set on the thermostat is too low
Heating element failure

LED is not on

No supply voltage; thermostat failure;
Safety thermostat shut off probably due to failed
operation thermostat

Water is not warm enough

LED is on

failure of one of the coils in the element
(contains 2)

Temperature of water is not
corresponding

Defective thermostat

Water is constantly dripping of
the safety valve

LED is not on

Input pressure too high; faulty safety valve

Do not try to repair the failure yourselves. Seek either expert or service help. It does not take much for an expert to
remove the defect. When making a repair appointment, report the type and serial number you find on the

performance plate of your water heater.

16. PRODUCT ACCESSORIES

The product is supplied with a safety valve, 2 – 4 fastening screws M 12x30, 2-4 washers  13
(OKCE version has them mounted in the hinges on the heater) and a thermometer. The above parts are
packed and placed in the packaging in the top part of the heater.

It is in your own interest to check the completeness of the accessories.

9

Type OKC 80 OKC 100 OKC 125 OKC 160 OKC 180 OKC 200

OKC 100/1m2OKC 125/1m2OKC 160/1m2OKC 180/1m2OKC 200/1m

2

OKCE 50 OKCE 80 OKCE 100 OKCE 125 OKCE 160 OKCE 180 OKCE 200

Capacity K / E l 51 75 / 80 95 / 100 120 / 125 147 / 152 175 / 180 195 /200

Max operating overpressure in the tank MPa

Maximum operating overpressure in the exchanger* MPa -

Electric connection V

Power input W

El.protection

Max temperature of HSW °C

Recommended HSW temperature

°C

Height of the heater mm 561 736 881 1046 1235 1187 1287

Diameter of the heater mm 524 524 524 524 524 584 584

Max weight of the heater without heater kg 30 42/36 52/58/42 58/64/48 66/72/58 76/82/72 81/88/76

Time of el.heating from 10°C to 60°C hod 1,5 2,5 3 3,8 5 5 5,5

Heat losses/energy efficiency class kWh/24h 0,45/C 0,71/C 0,88/C 1,09/C 1,33/C 1,39/C 1,4/B

Type OKC 80 OKC 100 OKC 125 OKC 160 OKC 180 OKC 200

Exchanger heat surface

m

2

- 0,41 0,68 0,68 0,68 0,68 0,68

Rated thermal output at heating water temperature of 80°C

and flow 720 l/h

W - 9000 17000 17000 17000 17000 17000

Time of heating by exchanger from 10°C to 60°C at flow of

720 l/hr

min - 32 23 28 35 40 45

Rated thermal output at heating water temperature of 80°C

and flow 310 l/h

W - 7000 9000 9000 9000 9000 9000

Time of heating by exchanger from 10°C to 60°C at flow of

310 l/hr

min - 50 48 55 75 77 86

Type

OKC 100/1m2OKC 125/1m2OKC 160/1m2OKC 180/1m2OKC 200/1m

2

Exchanger heat surface

m

2

- - 1,08 1,08 1,08 1,08 1,08

Rated thermal output at heating water temperature of 80°C

and flow 720 l/h

W - - 24000 24000 24000 24000 24000

Time of heating by exchanger from 10°C to 60°C min - - 14 17 23 26 28

*The OKCE series heaters do not have a heat exchanger

60

0,6

2200

1

0,6

1 PE-N 230V/50Hz

2000

IP 45

80

9

Fig. 1

Fig. 2 Fig. 3

Fitting of hinges and indicator onto the heater

Connection on the cold water inlet must conform to ČSN 06 0830

10

Fig. 4

OKC 80, OKC 100, OKC 125, OKC 160, OKC 180, OKC 200
OKC 100/1m2, OKC 125/1m2, OKC 160/1m2, OKC 180/1m2, OKC 200/1m2

type

OKC 80

OKC 100

OKC 125

OKC 160

OKC 180

OKC 200

OKC 100/1m2

OKC 125/1m2

OKC 160/1m2

OKC 180/1m2

OKC 200/1m2

A

736

881

1046

1235

1187

1287

B*

731

876

1041

1230

1182

1282

C

615

765 / 636

765/801

1005

793

793 D 524

524

524

524

584

584

E

501

651 / 701

651 / 701

651 / 701

685

685 F -

- / 551

- / 551

- / 831

- / 895

- / 895

G

G3/4"

G3/4" / G1"

G3/4" / G1"

G3/4" / G1"

G3/4" / G1"

G3/4" / G1"

H - - / G3/4"

- / G3/4"

- / G3/4"

- / G3/4"

- / G3/4"

I

211

211

211 / 261

211 / 261

245

245 J - - -

720 / 815

600

600

*Distance from the upper heater's edge to the end of the water inlet and outlet
tubes. Check the B and N dimensions before drilling.
The values behind the slash apply to heaters with a 1.08 m2 exchanger.

Upper and lower
Hinge 160,180, 200L
4 anchor bolts
Dimensions 450mm
and E
Check before drilling

Upper hinge and
support
80-125L
2 anchor bolts

11

Fig. 5

OKCE 50, OKCE 80, OKCE 100, OKCE 125, OKCE 160, OKCE 180, OKCE 200

Fig. 6

05-2011

Type

OKCE 50

OKCE 80

OKCE 100

OKCE 125

OKCE 160

OKCE 180

OKCE 200

A

561

736

881

1046

1235

1187

1287

B*

556

731

876

1041

1230

1182

1282

C

448

615

765

765

1005

793

793

D

524

524

524

524

524

584

584

E - - - -

720

600

600

*Distance from the upper heater's edge to the end of the water inlet and outlet tubes.

Upper and lower
hinge 160,180, 200L
4 anchor bolts
Dimensions 450mm
and E
Check before drilling

Upper hinge and
support
50-125L
2 anchor bolts