Dražice OKCE 100 NTR/2, 2kW, OKCE 125 NTR/2 Operating And Installation Manual

OPERATING AND INSTALLATION MANUAL

STATIONARY WATER HEATERS

OKCE 100 NTR/2,2kW
OKCE 125 NTR/2,2kW

Družstevní závody Dražice-strojírna s.r.o.

(Works Cooperative - Dražice – Machine Plant, Ltd.)

Dražice 69

294 71 Benátky nad Jizerou

Tel.: [phone], Fax: [phone]

www.dzd.cz
[e-mail]

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OKCE 100 NTR/2,2 kW

100 2,7 6

OKCE 125 NTR/2,2 kW

125 3,5 7,5

Heat losses

((Wh/24hr)/l)

Nominal

capacity (l)

Time of
content
heating

(hours)

Electricity

consumption for

heating of volume

from 15°C to 65°C

(in kWh)

Heat losses
((kWh/24hr)

Heater types

Energy

efficiency

class

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

Data sheet pursuant to Directive No 442/2004 Coll. and Annex No 7

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.
With this guide, we will introduce you to the use, construction, maintenance and other information on indirect
water heaters. Product’s reliability and safety is proven by tests implemented by the Engineering Test Institute in
Brno.

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

Guide Contents

1. USE ................................................................................................................................................................................ 2

2. PRODUCT DESCRIPTION ......................................................................................................................................... 3

3. IMPORTANT NOTICES ............................................................................................................................................. 3

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

5. PUTTING THE HEATER INTO OPERATION ......................................................................................................... 4

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

7. TECHNICAL PARAMETERS .................................................................................................................................... 6

8. PLUMBING FIXTURE ................................................................................................................................................ 7

9. ELECTRIC INSTALLATION ..................................................................................................................................... 7

10. TECHNICAL DATA CHART...................................................................................................................................... 8

11. PRESSURE LOSSES .................................................................................................................................................... 8

12. EXAMPLES OF HEATERS CONNECTION ............................................................................................................. 9

13. SPARE PARTS ........................................................................................................................................................... 10

14. HEATER CLEANING AND ANODE ROD EXCHANGE ....................................................................................... 10

15. INSTALLATION REGULATIONS ........................................................................................................................... 11

1. USE

Thanks to their construction and number of variants, the OKCE 100, 125 NTR series water heaters enable
economic preparation of hot service water (HSW) by means of various power sources. Their nominal performance
provides sufficient amount of hot water for flat units, premises, restaurants, and similar establishments. For HSW
reheat, electricity, various types of central heating boilers, recoverable energy sources (heat pumps, solar
collectors) and combination of those can be chosen.

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 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.

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2. PRODUCT DESCRIPTION

The heater tank is welded from a steel sheet; the exchangers from a steel tube and, as a unit, it is entirely coated
with hot water resistant enamel. A flange is welded onto the upper bottom of the receptacle 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. Electric wiring is placed underneath the plastic removable cover. The temperature of water can be
set using the thermostat.
For additional corrosion protection a magnesium anode is mounted in the upper part of the heater to adjust the
electric potential inside the tank, reducing the risk of corrosion. The heaters have outlets of hot and cold water and
a circulation opening welded to them. The tank is insulated with polyurethane foam of 40 - 65 mm thickness. The
heater shell consists of a steel, powder-paint coated, sheet; the connecting parts are metal coated. The entire heater
stands on three rectification screws with a possibility of levelling floor unevenness within the range of 10 mm. The
heater is to be placed on the ground. The tank is tested with pressure of 0.9 MPa, heat exchangers with 1.5 MPa.
The NTR version has a heat exchanger located in the bottom part of the heater, and one heating water source is
used for heating.

Placement and environment type

The heater is placed on the ground, next to the heating water source, or in its vicinity. All connecting distributions
must be properly insulated from heat. It is recommended to use the product in an indoor environment with air

temperatures from +2 to 45°C and a maximum relative humidity of 80%.

3. IMPORTANT NOTICES

- Without a proof issued by a professional company about performed electrical and plumbing fixture the

warranty shall be void.

- The Mg anode has to be checked regularly and exchanged, if needed.

- No stop valves can be put between the heater and the safety valve.

- All outlets of hot water must be equipped with a combination faucet.

- Before the first filling of water heater it is recommended to tighten the nuts of the flange joint of the tank.

- It is not allowed to handle the thermostat, aside from temperature resetting with a control button.

- All electric installation handling, setting, and regulation feature exchange, may only be implemented by a service

company.

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

power supply to the heating element if the water temperature in the heater exceeds 95°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. In case a solar system is connected to the

bottom exchanger, it is necessary to connect a TJ 6/4" line element in the coupling above the heater for potential
additional heating.

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 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.

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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. PUTTING THE HEATER INTO OPERATION

After connecting a heater to the water main, the hot water heating system, the 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 thermostat and then the safety fuse.

b) Open the hot water valve on the combination faucet;
c) open the cold water inlet valve to the heater;
d) when the water starts flowing through the hot water valve, the filling of the heater is finished and the valve

needs to be closed;

e) Should a leak (of the flange lid) occur, we recommend tightening the screws of the flange lid;
f) Fasten the electric installation cover;
g) When heating service water heating by electric energy, turn on the electricity (for combined heaters, the

heating water inlet to the heating insert must be closed);

h) When heating the water with thermal energy from a hot water heating system, turn off the electricity and open

the valves at the inlet and outlet of heating water or bleed the exchanger. When commencing operation, flush
the heater until the cloudiness in the water is gone.

i) Make sure to fill in properly the warranty certificate.

5. SERVICING

Service devices of heaters of 80 to 200 l capacity are located under the transparent guard of the control panel.

Thermostat knob Indicator - Boost heating Lamp switching circuit Thermostat knob

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