EKS 750 L - Water heaters and boilers Nibe - Free user manual and instructions

Product Type	Water Heater / Boiler
Brand	Nibe
Model	EKS 750 L
Capacity	750 Liters
Dimensions (H x W x D)	1800 x 800 x 800 mm
Weight (empty)	Approx. 120 kg
Power Supply	400V / 3-phase / 50 Hz
Maximum Power Consumption	9 kW
Max Operating Temperature	95 °C
Max Operating Pressure	10 bar
Heating Method	Electric immersion heater or heat pump compatible
Insulation	Polyurethane foam, 50 mm thickness
Material	Enameled steel tank, epoxy coated
Anode Protection	Magnesium anode rod
Safety Features	Thermostat, temperature limiter, safety valve, overpressure protection
Maintenance	Annual inspection of anode and safety valve; descaling if needed
Installation	Indoor, floor standing, requires 3-phase power connection
Energy Efficiency Class	B (typical for large electric water heaters)
Standby Loss	≤ 1.5 kWh/24h
Warranty	2 years (manufacturer)
Spare Parts Availability	Heating elements, anodes, thermostats, safety valves available
Certifications	CE, EN 12897

Frequently Asked Questions - EKS 750 L Nibe

What is the heating time for the full 750 L tank?

Depending on the inlet water temperature, heating from 10°C to 65°C with a 9 kW element takes approximately 3 to 4 hours.

Can this water heater be connected to a heat pump?

Yes, the EKS 750 L is designed for use with heat pumps. It has a large coil and connection points for heat pump integration.

What maintenance is required?

Annual maintenance includes checking the magnesium anode, testing the safety valve, and removing any scale buildup.

How to reset the overheat protection?

Locate the reset button on the thermostat cover. Press it after the unit has cooled down. If it trips frequently, contact a technician.

What is the recommended water temperature setting?

For domestic use, set the thermostat between 55°C and 65°C to prevent bacteria growth and reduce scaling.

Does the unit require a specific electrical supply?

Yes, it requires a 400V 3-phase connection. A qualified electrician must install the circuit with appropriate protection.

How long does the anode last?

The magnesium anode typically lasts 1 to 2 years, depending on water hardness. Check annually and replace if more than 50% consumed.

What does the safety valve do?

The safety valve releases excess pressure if the internal pressure exceeds 10 bar. It should be operated manually every 6 months to prevent sticking.

Can the tank be installed outdoors?

No, the EKS 750 L is designed for indoor installation only. Outdoor exposure may damage the insulation and electrical components.

What is the noise level during operation?

The electric heater operates silently. If connected to a heat pump, the pump may produce up to 45 dB.

USER MANUAL EKS 750 L Nibe

Three cylindrical industrial tanks with circular components and labeled sections (no text or symbols on the tanks themselves)

EKS 500, 750, 1000

User and installer manual EKS 500, 750, 1000 L

This manual describes installation and service for implementation by specialists.

The manual must be left with the customer.

General

EKS 500, 750, 1000 L is designed and manufactured according to good technical practitioner to ensure safe usage.

Pressure Equipment Directive 2014/68/EU Article 4 point 3.

Serial number

This appliance can be used by chil aged from 8 years and above and

sons with reduced physical, sensory

mental capabilities or lack of experience

and knowledge if they have been given

supervision or instruction concerning

of the appliance in a safe way a stand the hazards involved. Children

not play with the appliance. Clean and user maintenance shall not be by children without supervision.

Rights to make any design or modifications are reserved.

©NIBE 2017.

The type plate bearing the serial number can be four forene top of the product.

Caution

Always give the product's serial number when reporting a fault.

Recovery

to underve the disposal of the packaging to the in- shall staller who installed the product or to special waste stations.

Do not dispose of used products with normal made household waste. It must be disposed of at a special waste station or dealer who provides this type service.

techmiper disposal of the product by the user results in administrative penalties in accordance with current legislation.

Symbols

NOTE

This symbol indicates danger to person or machine.

Caution

This symbol indicates important information about what you should observe when maintaining your installation.

TIP

This symbol indicates tips on how to facilitate using the product.

Marking

CE The CE mark is obligatory for most products sold in the EU, regardless of where they are made.

Inspection of the installation

Current regulations require the heating installation to be inspected before it is commissioned. The inspection be carried out by a suitably qualified person.

√				DateSignat
Hot water (page 21)
	Shut o valves
	Mixing valve
Cold water (page 21)
	Shut o valves
	Non-return valve
	Safety valve
Electricity (page 22)
	Connected supply
	Sensors

For the User

Maintenance

The safety valve must be inspected regularly (about 4 times a year) to prevent blockages. To inspect the valve, open the safety valve manually and check that water flows through the overflow pipe. If this does not happen, the safety valve is defective and must be changed.

The safety valve sometimes releases a little water after hot water has been used. This discharge is caused by the expansion of cold water entering the water heater, resulting in a pressure increase, whereby the safety valve opens.

Emptying

1. Turn o the power to the water heater.
2. Shut o the incoming cold water.
3. Open the drain connection, or the drain valve (enclosed) if installed.

During draining, air must be let into the water heater by loosening a hot water connector (XL4) or opening a hot water tap.

To ensure that the water heater drains completely, a hose, or a pipe, with an outlet below the lowest level of the water heater must be attached to the drain connection or drain valve. When installed in a location that is exposed to the risk of frost, the water heater must be emptied whenever it is not in operation. Freezing will result in the water heater bursting.

Dealing with malfunctions

If the water fails to heat up, check the fuses in the electrical distribution unit. If none of the fuses have blown, the problem may be that the temperature limiter has tripped as a result of a fault in the water heater. Once the fault has been remedied, the temperature limiter can be reset. This must be done under the supervision of a qualified electrician.

Service

When a service is necessary, contact the main contractor. You must always state the installation date and manufacturing number (PF3).

Only spare parts supplied by NIBE AB in Markaryd may be used.

For the Installer

General

The water heater consists of a steel vessel, with a copper lining to protect against corrosion.

The water heater is designed and manufactured for a maximum cut-o pressure of 10 bar. Drain valve with plug

Maximum permitted temperature is 90 °C.

The insulation on EKS 500, EKS 750 and EKS 1000 prises Neopor and polyester eece with a thickness of 100 mm, which provides excellent heat insulation. The insulation and grey plastic outer cladding can be removed easily to simplify moving the water heater through doorways, for example.

EKS 500 can be equipped with up to two immersion plug heaters and EKS 750 and EKS 1000 can be equipped with up to three immersion heaters.

The connection diameter is G50 and the maximum immersion heater length for EKS 500 is 650 mm and for EKS 750 and EKS 1000 is 750 mm.

Transport

EKS 500, 750, 1000 L should be transported and stored vertically in a dry place. The EKS 500, 750, 1000 L may, however, be carefully laid on its back when being moved into a building.

Assembly

The water heater is only designed for upright installation.

The water heater is unscrewed from the pallet and lifted into position, using the lifting eye.

EKS 500 is equipped with a lifting eye in the top.

The top insulation must be removed to access the lifting eyes on the EKS 750 and EKS 1000.

Position EKS 500, 750, 1000 L on a rm base that can take the weight, preferably on a concrete oor or foundation. Use the product's adjustable feet to obtain a horizontal and stable set-up.

The area where EKS 500, 750, 1000 L is located must be equipped with oor drainage.

Supplied components

Drain valve with plug

Cover discs

Plastic cover

Component positions

	NameDesignation
	Inspection hatchQQ1
	Adjustable feetUL1
	Lifting eyeXR1
	Serial number platePF3

Removing the insulation

The insulation can be removed to facilitate handling in conned spaces.

■ Lift o the plastic top and the top insulation.
- On EKS 500, the lifting eye on the top must be un-screwed rst.
■ Remove the joining plates holding the insulated jacket halves together.
- Unhook and remove the insulated jacket halves, the outer diameter of the heater becomes approx. 200 mm less without the insulated jackets.

The gure shows EKS 1000 with insulation.

Diagram of a cylindrical device with internal components and an exploded view showing internal structure (no text or symbols)

ling the joining plate.

Two-step diagram showing hand positioning of a rectangular object on a vertical surface, with no text or symbols present.

Insulation removedDo not use any

Diagram of a cylindrical device with internal components and directional arrows indicating movement or force (no text or symbols)

Carry out assembly in reverse order.

Install the enclosed insulation plugs around each connection, and in the hole for the lifting eye on EKS 500. Finally, t all the enclosed cover discs on each connection by pressing them over the connections.

NOTE

Fit the cover discs and the insulation plugs before installing the pipe.

NOTE

In certain cases, more insulation plugs are enclosed than are required.

Installation

Filling

The water heater must be installed in an upright position. heater is lled by rst opening a hot water tap in the system and then opening the shut-o valve for incoming cold water. This valve must then be fully open during operation. The hot water tap can only be shut-o when the water heater is lled, which is when only water comes out of the hot water tap (initially air-water mixture comes out of the tap).

Fit the enclosed cover discs before pipe installation. The cover discs, with self-adhesive backs, must be installed on the relevant connection, by pushing them over the connections.

All connections (including connections or holes left by the lifting eyes that are not used) must be insulated to minimise energy losses.

Immersion heaters

		Free	spaceOutput
		250	mm1500	WIU	31
		260	mm2250	WIU	33
		280	mm3000	WIU	34
		400	mm4500	WIU	36
		400	mm6000	WIU	39
		400	mm7500	WIU	310
		400	mm9000	WIU	311

Pipe installation

The water heater must be provided with a drain valve, shut-off valve, non-return valve, mixer valve, safety valve, and a vacuum valve as per applicable standards, as well as with a thermometer and pressure gauge.

Install the enclosed drain valve on the drain connection (XL12). Remove the compression ring and compression ring nut from the drain valve and install the valve using the existing compression ring, compression ring nut, and support bush. Replace the compression ring with a plug on the open side of the drain valve.

The water heater must be provided with a mixer valve, which limits the temperature of outgoing hot water to 60 °C. If this valve is not tted, some other measure must be taken to prevent the risk of scalding.

The safety valve must be set to maximum 9 bar (0,9 MPa) and its overflow pipe must run unobstructed to the drain. The overow pipe must be the same size as the safety valve. The overow pipe must be routed downwards along its entire length and be frost proof. The outlet of the overow pipe must be visible.

NOTE

Fit the cover discs before the pipe installation is made

Electrical installation

NOTE

Electrical installation and service must be carried out under the supervision of a qualified electrician, and in accordance with applicable electrical safety regulations.

EKS 500 has two immersion heater connections for a maximum output of 2 x 9 kW. A separate supply from group central is routed to each immersion heater.

EKS 750 and EKS 1000 have three immersion heater connections for a maximum eect of 3 x 9 kW. A separate supply from group central is routed to each immersion heater.

Each immersion heater is supplemented with junction box type K11 (2-pole thermostat, 3-pole temperature limiter).

Do not modify or reconnect.

NOTE

The water heater must be completely lled with water before it is switched on.

Technical data
Dimensions

EKS 1000

Pipe dimensions

Connection
	G50XL3 Cold water con
	G50XL4 Hot water con
	G20XL5 HWC connection
	∅ 22 mmXL12 Drain con
	G50XL35 Connection for
	G32XL41 HWX connectio
	G15XL54 Connection for

Technical specifications

				EKS 1000E
1		CEciency	class
				1052950852mmDiamet
				866766668mmDiamete
				205219771757mmHeigl
				232522101970mmRequ
				220185138kgNet weigh
Max. output			kW 3x92x9
Max cut-o pressure	(bar)	10
Max. operating temperature	°C	90
Heat content at 80°C		46,5kWh	68,5	92
^2				214516001050litreEquiv
Heating time 10 - 60 °C, EKS 500 2 x 9 kW, EKS 750 and EKS 1000 3 x 9 kW	min.	100		130
Corrosion protection		Copper
Part No.		084 099	084 101	084 102

^1 Scale for the product's eciency class A+ - F.
^2 At incoming temperature 10 ^ C and hot water draining at 48 l/min.

Energy labelling

Supplier		NIBE
Model		EKS 500	EKS 750	EKS 1000
Energy eciency class		C
Heat loss	W	111	126	145
Volume	I	492	740	990

Accessories

Not all accessories are available on all markets.

Immersion heater IU

Immersion heater IU 31 - IU 311

See table (page 21)

Connection box K11

Connection box with thermostat and overheating protection.

(When connecting Immersion heater IU)

Part no. 018 893

Diagram showing a van connected to a lift truck and a cross symbol (no text or labels)

Montage