Drazice OKC 200 NTRR, OKC 160 NTR, OKC 250 NTRR, OKC 200 NTR, OKC 100 NTR Operation And Installation Manual

Operation and Installation Manual

TANK TYPE INDIRECT WATER HEATERS

OKC 80 NTR/Z
OKC 100 NTR OKC 100 NTR/HV OKC 100 NTR/Z
OKC 125 NTR OKC 125 NTR/HV OKC 125 NTR/Z OKCV 125 NTR
OKC 160 NTR OKC 160 NTR/HV OKC 160 NTR/Z OKCV 160 NTR
OKCV 180 NTR
OKC 200 NTR OKC 200 NTR/Z OKCV 200 NTR
OKC 250 NTR
OKC 200 NTRR
OKC 250 NTRR

Družstevní závody Dražice - strojírna s.r.o.

Dražice 69

294 71 Benátky nad Jizerou

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

www.dzd.cz
[e-mail]

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

We believe you will be fully satisfied with our product.

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 ............................................................................................................................ 2

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

4. OPERATING ACTIVITY ................................................................................................................................... 5

5. SERVICING .................................................................................................................................................. 5

6. PLUMBING FIXTURE ...................................................................................................................................... 6

7. CONNECTION OF INDIRECT HEATER TO HOT WATER HEATING SYSTEM ................................................................ 7

8. WALL MOUNTING (applies to NTR/Z & OKCV NTR only) ........................................................................................ 10

9. ELECTRIC INSTALLATION ............................................................................................................................ 10

10. PUTTING THE HEATER INTO OPERATION ........................................................................................................ 11

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

12. IMPORTANT NOTICES .................................................................................................................................. 11

13. FIRE-FIGHTING REGULATIONS FOR INSTALLATION AND USE OF HEATER ............................................................ 12

14. INSTALLATION REGULATIONS ...................................................................................................................... 12

15. MOST FREQUENT FUNCTION FAILURES AND THEIR CAUSES .............................................................................. 12

16. PRODUCT ACCESSORIES .............................................................................................................................. 12

Environment Type:

It is recommended to use the product in indoor environment with air temperatures from +2°C to 45°C and a max.

relative humidity of 80%.

1. FUNCTION DESCRIPTION

Indirect stationary heaters of NTR and NTRR series are used for HSW water heating in conjunction with another source
of heating water, most often a gas boiler, for NTRR types combination of two heating water sources (gas boiler + solar
system, heat pump). Their nominal performance provides sufficient amount of hot service water (HSW) even for large flat
units - premises, restaurants and similar establishments. In case of increased hot water consumption, these tanks heat

water continuously, operating similarly to flow heaters.

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.

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Energy saving

Hot utility water reservoir is insulated by means of a first-class polyurethane foam with zero Freon 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 heat exchanger.

Advantages of using indirect heater

- Easy installation and connection to heating water supply.

- Very fast HSW heating

- Enamelled steel tank ensures all hygienic requirements on the quality of HSW.

- Built-in Mg anode increases resistance to corrosion.

- Good quality polyurethane insulation ensures minimum thermal losses.

- Continuously adjustable temperature of HSW| up to 74°C

- Connection of multiple withdrawal points.

- The type with two heat exchangers can use two heating water supplies, or double heat transfer surface can
be obtained if those are combined.

- Heater operation control light.

- Accurate check of HSW temperature.

- Possibility of connecting HSW circulation.

3. TECHNICAL DESCRIPTION

The heater receptacle 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 lower bottom of the receptacle with a flange lid screwed onto it. A sealing ring is
inserted between the flange lid and the flange.
Thermowells for thermostat sensors and thermometer installation are placed 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.
Heat exchanger(s) is/are welded onto the pressure tank.

Technical description:

OKC 100 NTR, OKC 125 NTR, OKC 160 NTR,
OKC 200 NTR, OKC 250 NTR,
OKC 200 NTRR, OKC 250 NTRR

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Technical description: OKC 100 NTR/HV, OKC 125 NTR/HV, OKC 160 NTR/HV

Technical description: OKC 80 NTR/Z, OKC 100 NTR/Z, OKC 125 NTR/Z, OKC 160 NTR/Z,

OKC 200 NTR/Z

Technical description: OKCV125 NTR, OKCV 160 NTR, OKCV 180 NTR, OKCV 200 NTR

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4. OPERATING ACTIVITY

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 the 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. 1) 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. Combined heater is made in universal design – depending on the need of connecting the closing valves to the
heating element from the right or left (Fig.1).

5. SERVICING

Service devices of heaters of 80 to 250 l capacity are located under the transparent guard of the control panel.

PANEL OF OKC NTR / Z & OKCV NTR HEATERS of 80 up to 200 l capacity

Thermostat knob Electric circuit closing indicator lamp Tipping transparent guard

PANEL OF OKC NTR,R & OKC NTR / HV HEATERS of 100 up to 250 l capacity

Temperature setting

Teplota vody se nastavuje otočením knoflíku termostatu. Požadovaný symbol se nastaví proti pevnému bodu na
ovládacím panelu.

Lower temperature range
limit (about 5°C)

Fixed point on the control
panel

Anti-freezing temperature
(about 8°C)

Notice: Adjusting the thermostat selector to the left backstop does not mean permanent shutoff of the heating element.

Upper temperature range
limit (about 74°C)

”Ideal” temperature (about
60°C)

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When the heater is in use without blocking the daily rate, we do not recommend the temperature to be set above 65°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 hard for the first time), and you will find two φ2.15mm

cylindrical pins 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

Regulation limited Setting blocked

To block the setting: - set the selected temperature

- pull off the thermostat knob without changing the setting, there are two pins on the back side of
the knob

- pull off 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. PLUMBING FIXTURE

Connection of heaters to plumbing fixtures is illustrated on Fig.1. For potential disconnection of the heater, the

service water inlets and outlets must be provided with screw coupling Js 3/4“. If the hot service water (HSW) distribution
is equipped with circulation circuit, the reverse pipe is connected to the inlet identified as CIRCULATION.
The 100, 125, 160 NTR and 100, 125, 160 NTR / HV types are equipped with a discharge outlet. In 200 and 250 NTR(R)
types, the HSW inlet has to be provided with a “T” fixture with a drain valve.
For operation, the heater must be equipped with a safety valve. 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 safety valve with a membrane spring. 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 in the direction of the arrow.
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)

0.6 0.6 do 0.48

0.7 0.7 do 0.56
1 1 do 0.8

Admissible operating

water heater

pressure (MPa)

Max. pressure in

the cold water pipe

(MPa)

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