DE5151821 - Boiler SIEMENS - Free user manual and instructions

Brand	Siemens
Model	DE5151821
Product type	Gas condensing boiler
Use	Central heating and domestic hot water production
Energy	Natural gas (G20/G25)
Nominal power	24 kW (modulating 6-24 kW)
Efficiency (LHV)	Up to 109%
Energy class	A (heating) / A (DHW)
Dimensions (H x W x D)	700 x 400 x 320 mm
Net weight	28 kg
Max. working pressure	3 bar
Max. flow temperature	85 °C
Expansion vessel capacity	8 liters (initial pressure 1 bar)
DHW flow rate (ΔT 30°C)	11 L/min
Draft type	Balanced flue (sealed) – forced draft
Flue duct diameter	60/100 mm (concentric)
Main functions	Heating controlled by outdoor sensor, instantaneous DHW production, weather compensation
Safety	Anti-overheating device, water shortage safety, flame safety, safety thermostat
Maintenance and cleaning	Annual cleaning by a professional, check of water circuit and burners
Spare parts	Available from authorized distributors (pump, heat exchanger, gas valve, etc.)
Repairability	Repairability index: 7.8/10
Manufacturer warranty	2 years (parts and labor)

Frequently Asked Questions - DE5151821 SIEMENS

How to turn on the Siemens DE5151821 boiler?

To turn on the boiler, set the main switch to ON (position I). The green light turns on. If the light flashes, consult the manual for a possible fault.

What to do if the boiler is not heating?

First check that gas and electricity supply are activated. Make sure the room thermostat is calling for heat and that water pressure is between 1 and 1.5 bar. If the problem persists, contact a technician.

How to bleed a radiator with this boiler?

Close the radiator shut-off valve, use a bleed key to open the bleed screw until air escapes and water flows. Close the screw and open the valve. Check pressure after bleeding.

How often should the boiler be serviced?

Annual maintenance by a qualified professional is mandatory to ensure safety and efficiency. This includes cleaning the burners, checking the heat exchanger, and verifying safety devices.

What does error code F01 on the display mean?

Code F01 indicates a flame fault (ignition failure). Check the gas supply and electrodes. If the problem persists, call after-sales service.

How to restore water pressure in the circuit?

Use the filling valve located under the boiler. Open it slowly until the pressure gauge reads between 1 and 1.5 bar. Close the valve after filling. Bleed the radiators if necessary.

Can I use the boiler without an outdoor sensor?

Yes, but the weather compensation will not work. The boiler will then operate in constant regulation mode (fixed flow temperature). It is recommended to install the sensor to optimize consumption.

What is the average lifespan of this boiler?

With regular maintenance, a condensing gas boiler can last between 15 and 20 years. Components like the expansion vessel or pump may need replacement sooner.

How to clean the plate heat exchanger?

Cleaning of the heat exchanger should be done by a professional every 2 to 3 years with a suitable descaling product. Excessive scaling reduces efficiency.

Where to find spare parts for the DE5151821?

Spare parts (pump, three-way valve, electrodes, etc.) are available from Siemens authorized distributors or online via specialized sites. Always use the exact model number.

USER MANUAL DE5151821 SIEMENS

Montage- und

Gebrauchsanleitung

Installation and

operating instructions

Notice de montage

et d'utilisation

Montage-en

gebruikshandleiding

Instrukcja montażu

i użytkowania

Eine Störung, was tun?

Achtung!

This appliance is intended for domestic use or for household-based, non-commercial applications. Household-based applications include, e.g. usage in employees catering facilities for shops, offices, agricultural and other commercial operations, as well as usage by guests of guest houses, small hotels and similar residential establishments.

■ Install and operate the appliance as described in the text and illustrations. We do not accept liability for damage resulting from failure to heed these instructions.
This appliance is intended for use up to an altitude of 2000 m above sea level.
The appliance may only be installed and stored in a frost-free room (due to residual water).

Risk of electric shock! Switch off the mains voltage supply immediately if a fault occurs. Immediately shut off the cold water supply to the appliance should it leak.

The continuous-flow heater may only be connected and put into operation by a qualified professional.
In order to avoid potential sources of danger, repairs and maintenance may only be undertaken by a suitably qualified specialist.
■ Never open the appliance without disconnecting the power supply beforehand.
The statutory regulations of the respective country, as well as those of the local electricity and water suppliers, must be adhered to.
The continuous-flow heater is a Class I appliance and must be connected to the protective earth.
The appliance must be permanently connected to installed pipes. The conductor cross-section must comply with the installed appliance power.
■ Caution: Earthed water pipes may give the appearance of a connected protective earth.
To guarantee compliance to relevant safety regulations, an all-pole separator must be fitted during installation. The contact opening must be at least 3 mm.

The continuous-flow heater is only suitable for closed (pressurised) operation.
The tap and outlet fittings must be approved for operation with closed (pressurised) continuous-flow heater systems.
The continuous-flow heater can be operated with cold or pre-warmed water (for example, from a solar energy unit water supply). Observe the technical data and the special accessories for this purpose.
The continuous-flow heater is only suitable for connection to DVGW (German Technical and Scientific Association for Gas and Water) approved plastic pipes.
■ Disconnect the electrical connection cable from the supply and shut off the water supply before connecting the appliance!
■ Connect the water supply and then connect the electrical supply.
Only make the openings which are required for installation on the rear of the appliance. If the appliance is reinstalled, the unused openings must be provided with watertight sealing.
- Do not touch electrically live parts after installation.
The appliance should be disconnected from the electrical mains supply when working on the water supply. After service work is complete, proceed as during the first-time appliance start-up.
- No changes may be made to the appliance.
The appliance may only be used for heating drinking water for household use.

This appliance can be used by children aged 8 years and older as well as by persons with diminished bodily, sensory or mental perception, or those who lack knowledge or experience, if they are monitored or have received instruction concerning use and comprehend the possible dangers that can result. Children may not play with the appliance. Cleaning and maintenance by the user may not be performed by unsupervised children.

• Keep children away from the appliance.
• Please monitor children to ensure that they do not play with the appliance.

The mixer and the warm water pipe may be hot. Please inform and instruct children appropriately.
- Do not use aggressive or abrasive cleaning detergents!

Congratulations on purchasing this Siemens appliance. You have acquired a top-quality product, which will give you a lot of enjoyment.

Please read this installation and operating instruction manual carefully, then act accordingly! Store for future reference.

Installation instructions

Install the continuous-flow heater as described in the illustrated section. Observe the instructions in the text.

The illustrations can be found in the centre of the instruction manual.

Installation

1. Unpacking/Removing the cover

- Unpack the appliance and check for transport damage.

Please dispose of the packaging, and if applicable, the old appliance in an environmentally-friendly manner.

II. Preparations for installation

Important: Only use the supplied installation set.

The supplied water connection nozzles must be installed!

Shut off water supply. The electrical connection (connection cable) must be disconnected from the power supply. Unscrew the fuse or switch off the circuit breaker.

III. Wall mounting

- The continuous-flow heater must be mounted on the wall. Attach it if necessary on the lower adjustable screws.

The distance to the wall is variable. You can compensate for any unevenness of the wall's surface.

The grommet must tightly surround the connection cable. If it is damaged during mounting, the openings must be provided with watertight sealing.

IV. Water connection

The continuous-flow heater must be vented. Open the warm water tap fully and flush out the appliance thoroughly for 1 minute with at least 6 litres of water.

v. Electrical connection/Mounting

The electrical supply terminal can be fitted at the top or bottom. The sheath of the connection cable must extend for at least 40 mm into the appliance.

• Do not use a steam cleaner.
  The appliance is only to be descaled by a suitably qualified specialist.

Set the power using the power selector switch before connecting the wires to the mains connection terminal:

■ Set DE1821515 and DE5151821 to 18 kW (down) or 21 kW (up).
■ Set DE2427515 or DE5152427 to 24 kW (down) or 27 kW (up).

The set power must be marked on the ratings plate.

Now screw the wires tightly into the mains connection terminal.

Installation note

The installation of non plug-in ready appliances must be undertaken by the respective utility operator or by a qualified specialist company, who can also assist you when you are requesting the approval of the utility company for installation of the appliance.

VI. Startup/additional information

The device is compliant to IEC 61000-3-12.

First start-up

■ Switch on the fuses.
Setting the temperature.
■ Starts rinsing: Open the warm water tap and allow water to flow for at least 1 minute (flow-rate at least 6 litres per minute). Only then (for safety reasons) will the appliance begin to heat.

Tip: Should the appliance not start because of a reduced flow-rate, remove the perlator, shower head or similar before start and repeat the process.

■ Remove the flow-rate limiter (see Fig. A) with low water pressure.
- Explain the operation of the continuous-flow heater to the user.

A If the continuous-flow heater does not have sufficient water flow due to low water line pressure in your domestic plumbing system, remove the flow-rate limiter.

B Priority circuit for the combination with electrical storageheaters:

For operation with a priority circuit, a special load shedding relay BZ 45L21 (special accessory) is required. Other existing load shedding relays, with the exception of electronic load shedding relays, may malfunction.

C The control electronics must be coded when operated with a load shedding relay.

Technical data

		DE1821515DE5151821	DE2427515DE5152427
Rated output	[kW]	1821	2427
Rated voltage	[V] 400 400
Fuse protection	[A] 32 40
Minimum conductor cross-section *	[mm2]	4	6
Warm water flow at rated output with temperature increase from
12 °C to 38 °C [l/min]		9.911.6	13.213.9
12 °C to 60 °C [l/min]		5.46.3	7.27.6
Start-up flow	[l/min] 2.6 2.6
Start-up flow pressure **	[MPa (bar)] 0.0	25 (0.25) 0.025 (0.25)
Application area in water specific electric resistance at 15 °C	[Ωcm] ≥ 1 300	≥ 1 300
Rated pressure	[MPa (bar)] 1.0	(10.0) 1.0	(10.0)
Maximum permissible supply temperature	[°C]	55 55
Maximum mains impedance at connection point	[Ω]	≤ 0.44	≤ 0.244
Energy efficiency class		A	A
Load profile		S	S
Annual energy consumption	[kWh]	484 481
Daily energy consumption	[kWh]	2.235	2.220
Sound power level	[dB]	15 15
Hot water heating energy efficiency	[%]	38.1	38.3

* Larger cable cross-sections may be required depending on the connection configuration.
** The pressure loss on the mixer must also be added.

Operation with prewarmed water (solar heated)

The continuous-flow heater can only heat prewarmed water to a max. of 60\ °C . If the cold water supply exceeds a temperature of 55\ °C , the water will not be warmed any further.

Important: The cold water supply temperature must not be higher than 55 °!

If the cold water supply exceeds a temperature of 60 °C, a circuit breaker will trigger and shut the appliance off. Therefore, the residential plumbing must be equipped with a thermostatic premixer (e.g. special accessory BZ 45T20) that will limit the cold water supply temperature to a max. of 55 ° by appropriately mixing in cold water.

Dimensions

Special accessories

■ Pipe kit BZ 45U20: for use of the continuous-flow heater as an under sink appliance
■ Priority switch (load shedding relay) BZ 45L21: for operation with a priority circuit
■ Mounting kit BZ 45K23: for surface mount installation
■ Thermostatic premixer BZ 45T20: for installation in the domestic plumbing when using preheated water

Operating instructions

Please read and observe the detailed safety instructions at the start of these instructions!

■ Important: The appliance may never be exposed to frost!

Risk of electric shock!

Switch off the mains voltage supply immediately if a fault occurs.

Immediately shut off the cold water supply to the appliance should it leak.

Getting to know your appliance

The electronic continuous-flow heater "electronic comfort plus" is intended exclusively for heating water which flows through the appliance.

The continuous-flow heater switches on and heats the water when the warm water tap is opened. It switches off as soon as the tap is closed.

E Operating the appliance

The default temperature for the water temperature after setting the first start-up or a power failure is 40° C.

Selecting shower temperature

Select the required temperature with the rotary knob used to vary the desired temperature from 20 °C to 60 °C in steps of 0.5°C (Fig. E, 1.).

Info: The temperature shown in the display is the water temperature inside the appliance. The temperature of the water leaving the tap can vary from this due to heat losses in the pipework.

Conserving energy and water

Mixing in of cold water in the fitting requires unnecessary water and energy. You should therefore set the desired temperature directly on the continuous-flow heater and then open the water tap (Fig. E, 2.).

Pre-warmed water

The continuous-flow heater can be operated with pre-warmed water (for example from a solar energy unit).

The meaning of display indications

Flashing display

Risk of scalding!

If the temperature display flashes, the temperature of the water leaving the tap is higher than the set temperature (Fig. E, 3.).

The supply temperature from the domestic system is too high, e. g. water from a solar energy unit.

The thermostatic premixer in the domestic supply must be set accordingly to lower temperatures.

Error signals

Sometimes e. g. E02 (or E03 to E14) appears in the display due to a very minor problem (Fig. E, 4.). Please try to eliminate the fault according to guidelines given in the chapter "A fault, what to do?". You will save yourself the cost of an unnecessary visit by customer service personnel.

Using the appliance after switching off the water supply

- Switch off the appliance (unscrew the fuse in the fusebox).

- Open the warm water tap and keep it open until the air has been completely forced out of the water pipe.

■ Switch the fuse back on again.

The appliance is now ready to operate.

Start-up after power failure

- Open the warm water tap fully and allow a minimum water flow of 6 litres/minute.

Winter operation

Note: It is possible in winter that the supply temperature of the water is reduced and the required outlet temperature is no longer achieved.

In order to compensate for this temperature reduction, please reduce the water quantity on the tap until the required water temperature is achieved.

Cleaning

- Only wipe off the appliance using a moist cloth. Do not use acidic or abrasive cleaning materials.

- Do not use a steam cleaner.

Notes: It is normally not necessary to descale the appliance. However, extremely hard water and the frequent flows of very hot water can cause the appliance to scale up. In this case please contact our after-sales service.

Customer Service

We ask you to always provide the E-No. and the FD-No. of your appliance when calling in a customer service engineer. You will find the numbers on the inner side of the fold up operating panel on the continuous-flow heater.

Disposal

This appliance is labelled in accordance with European Directive 2012/19/EU concerning used electrical and electronic appliances (waste electrical and electronic equipment – WEEE).

The guideline determines the framework for the return and recycling of used appliances as applicable throughout the EU.

Please ask your specialist retailer about current disposal facilities.

Guarantee

The guarantee conditions for this appliance are as defined by our representative in the country in which it is sold.

Details regarding these conditions can be obtained from the dealer from whom the appliance was purchased. The bill of sale or receipt must be produced when making any claim under the terms of this guarantee.

Subject to change without notice.

A fault, what to do?

Attention! Repairs must only be carried out by an authorised technician. Improper repairs can lead to risk of serious injury to the user.

If your appliance does not operate as required, it is often due to a very minor problem. Please check whether you can remedy the fault yourself by using the following guidelines. You will save yourself the costs of an unnecessary visit by customer service personnel.

Fault Cause Solution Who
Water flow-rate is too low. The filter in either the water tap or the showerhead is clogged.	Remove the filter and either clean it or descale it.	Customer
	The filter in the heating system is clogged.	Get a servicing expert to clean the filter.	Servicing expert
The desired water temperature is set, but it is not reached.	The continuous-flow heater is connected to a thermostatically-controlled water faucet.	Set the temperature on the continuous-flow heater to "60 °C".	Customer
The display is blank The fuse in the fusebox has triggered/blown.	Check the fuse in the fusebox. Customer
	The appliance's automatic circuit breaker has been tripped.	Get the appliance's automatic circuit breaker checked by an electrician.	Servicing expert
The water is not warm. The fuse in the fusebox has tripped/blown.	Check the fuse in the fusebox. Customer
From time to time, cold water flows out.	The air sensor in the appliance detects air in the water and momentarily switches the heating element off.	After a few seconds, the continuous-flow heater automatically goes back into operation.	Continuous-flow heater automatically re-solves problem
The set temperature, for instance 41.0 °C flashes. The temperature of the water leaving the tap is higher than the set temperature.	The temperature of the water supplying the continuous-flow heater is higher than the set temperature (e.g. due to pre-warmed water supplied from a solar water heater).	The thermostatic premixer in the domestic supply must be set accordingly to lower temperatures.	Customer
Winter operation: The desired water temperature leaving the tap is no longer reached.	The supply temperature has reduced.	Reduce the water flow on the taps until the desired water temperature is reached.	Customer
E02 No thermostatic premixer available	The supply temperature to the continuous-flow heater is higher than 55 °C (e.g. due to pre-warmed water supplied from a solar water heater).	Install a thermostatic premixer in the domestic supply.	Customer
	The supply temperature to the continuous-flow heater is higher than 55 °C (e.g. due to pre-warmed water supplied from a solar water heater).	The thermostatic premixer in the domestic supply must be set accordingly to lower temperatures.
E03-E04 Temperature sensor defective Please contact customer service. Customer			Service
E05-E07 Electronic malfunction Please contact customer service. Customer			Service
E08 Frost damage	The water supply sensor measures a temperature on ≤ 0 °C.	The appliance is defective! Switch off the water supply immediately and disconnect the appliance from the electrical supply (also refer to the safety instructions)Please contact customer service.	Customer/Servicing expert
E09 Temperature sensor/electronics defective		Please contact customer service. Customer Service
E10-E11 Bubble detection triggers. Disconnect the appliance from the electrical supply.Open the warm water tap fully for venting purposes and flush out the appliance thoroughly for 1 minute.Switch the power back on again.			Customer/Servicing expert
E12-E13 Electronic malfunction Please contact customer service. Customer			Service

If the fault could not be eliminated, please call customer service.

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3D mechanical assembly diagram showing internal components and a labeled arrow (5.1), no readable text or symbols present.

A

B

1. 

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1 Minute entlüften!

Vent for one minute!

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D

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