Method for operating a heating device, computer program, regulating and control device and heating device

Abstract

A method for operating a heating appliance (1) is proposed. The heating appliance (1) comprises a burner (3) to which a mixture of fuel gas and combustion air is supplied via a mixture channel (11) by means of a conveying device (2), and a flame arrestor (12) designed to prevent the propagation of a flame from the burner (3) towards the mixture channel (11). The method comprises at least the following steps: a) Determining at least one parameter that allows conclusions to be drawn about the flow resistance of the flame arrestor (12), b) Determining a time course of the parameter determined in step a) or a quantity or function derived therefrom, c) Determining the permeability of the flame arrestor (12) in view of the time course determined in step b). A computer program, a control and monitoring device (7), and a heating appliance (1) are also specified.

Description

[0001] The invention relates to a method for operating a heating device, a computer program, a control and regulating device and a heating device.

[0002] A variety of heating appliances are known that burn a mixture of a fuel, especially gas or hydrogen, and ambient air in a combustion chamber to generate heat for supplying a building or for providing hot water.

[0003] With the increasing use of hydrogen as a fuel, the risk of flame flashback in such heating appliances rises. One reason for this is the significantly higher flame speed of hydrogen compared to other fuels. A flame flashback refers to the propagation of a flame from the burner towards the fuel feed of the heating appliance, causing considerable noise and potentially leading to damage to the appliance, such as a conveying mechanism (like a fan).

[0004] To improve the operational safety of a heating appliance, EP 3 043 115 B1 proposes carrying out various tests, including a pre-purge test, an ignition test, a draft test, a gas pressure test, a running test, and a post-purge test, based on signals from an ionization sensor, the fan, or a temperature sensor to measure the exhaust gas temperature. However, this method cannot prevent the occurrence and consequences of a flame flashback.

[0005] To prevent flame flashbacks, flame arresters can be used, which often cover the available flow cross-section, particularly in the area between the burner and the mixture supply, and cannot be penetrated by a flame. A heating device with such a flame arrester is presented, for example, in DE10 2020 125 351 A1.

[0006] EP 3 974 719 A1 also proposes installing a flame arrestor between an air supply and a perforated plate of the burner, which is impenetrable to a flame. This prevents further penetration of a flame into a mixed gas line of the heating appliance.

[0007] WO 2022 / 0033123 A1 proposes a device for preventing flame flashback, comprising a housing with an integrated backflow preventer, a gas non-return valve arranged in the housing, and at least one sintered body and a sensor device arranged therein. This device is not suitable for installation in a mixture channel or a burner of a heating appliance and therefore cannot prevent flame propagation into the mixture channel of a heating appliance.

[0008] Flame arrestors are often made of an open-pored material or textile structures, such as a non-woven fabric. A disadvantage of flame arrestors is that they can become clogged over extended periods of use, for example, by dust from the combustion air intake. A clogged flame arrestor can reduce the combustion efficiency of a heating appliance or even prevent the appliance from starting (ignition).

[0009] According to current technology, a blocked flame arrestor (either accidentally or during a maintenance appointment) is detected by visual inspection by a qualified technician. If necessary, the flame arrestor can be replaced or regenerated. The disadvantage is that until the blocked flame arrestor is detected, the heating appliance is often operated at reduced efficiency.

[0010] EP 3 932 496 B1 describes a device for preventing flame flashback for use in a fuel gas line. The device comprises a backflow preventer, a non-return valve, a sintered body to prevent flame penetration, a sensor for detecting flame flashbacks, and a flow meter to check the patency of the sintered body. A disadvantage is that the device is hardly suitable for use with a heating appliance, and the use of the flow meter is complex and carries a risk of failure.

[0011] Based on this, the object of the invention is to propose a method for operating a heating device that at least partially overcomes the problems of the prior art described above. In particular, a clogged flame arrestor should be detected in a timely and automated manner.

[0012] Furthermore, the invention should not significantly increase the complexity of a heating device and should only require minor structural changes to a heating device.

[0013] These problems are solved by the features of the independent claims. Further advantageous embodiments of the solution proposed here are specified in the independent claims. It should be noted that the features listed in the dependent claims can be combined with one another in any technologically meaningful way and define further embodiments of the invention. Furthermore, the features specified in the claims are further specified and explained in the description, which also presents further preferred embodiments of the invention.

[0014] This is achieved by a method for operating a heating appliance, wherein the heating appliance comprises at least one burner to which a mixture of fuel gas and combustion air is supplied via a mixture channel by means of a conveying device, and a flame arrestor designed to prevent the propagation of a flame from the burner towards the mixture channel. The method comprises at least the following steps: a) Determining at least one parameter that allows conclusions to be drawn about the flow resistance of the flame arrestor, b) Determining a time course of the parameter determined in step a) or a quantity or function derived from it, c) Determining a reduced permeability of the flame arrestor in view of the time course determined in step b).

[0015] At least one parameter from the following group is selected: A signal from a flow sensor located in the combustion air supply of the heating appliance. The flow sensor can be a mass flow or a volume flow sensor. Various operating parameters of the conveying device: The rotational speed of a conveying device designed as a fan. This can be useful, for example, in heating appliances with a flow sensor for fuel, combustion air, or a mixture thereof, as increased flow resistance can be compensated for by increasing the rotational speed to maintain a constant flow rate. The (electrical) power consumption of the conveying device or its electrical supply current. A control signal from a controller of the conveying device, where the controller can be, in particular, a speed controller and the control signal, in particular, a pulse-width modulated signal. A measured pressure in the flow path of the heating appliance.In particular, two pressure values ​​can be recorded, one before and one after the flame arrestor. For this purpose, appropriate pressure sensors can be installed before and after the flame arrestor. This allows the pressure drop at the flame arrestor to be determined directly.

[0016] Steps a), b), and c) can be performed at least once in the specified order. In particular, step a) can be performed at regular intervals (hourly, minutely) during the operation of a heating appliance. This procedure is primarily used to detect reduced permeability of a flame arrestor in a heating appliance and can thus increase operational safety and help ensure efficient operation of the heating appliance.

[0017] The heating appliance in question is, in particular, a gas-fired heating appliance designed to burn a fuel gas, such as natural gas or, more specifically, hydrogen, with the addition of ambient air (combustion air) to generate heat energy, for example, to heat a heat transfer fluid in a heating circuit or to provide hot water. The heating appliance may, in particular, be a condensing boiler. The heating appliance typically has a combustion chamber and a conveying device or fan that can supply a mixture of fuel and combustion air via a mixture channel (mixture gas channel, mixture feed) into a combustion chamber in which a burner is located. The combustion products can then be discharged through an exhaust gas duct of the heating appliance into a flue system.

[0018] The conveying device may include a controller, for example a speed controller of a conveying device designed as a blower, which regulates a predetermined speed of the blower by means of a control signal, often a pulse width modulated (PWM) signal.

[0019] Often, a defined fan speed is set or regulated for power control (modulation) of the heating appliance. Such heating appliances cannot compensate for increased flow resistance due to a clogged flame arrestor, and consequently, increased flame arrestor flow resistance results in a reduced mass flow rate through the conveying system and a corresponding reduction in heat output.

[0020] Alternatively, a measured flow rate (mass flow, volume flow) of fuel, combustion air, and / or a mixture thereof can be incorporated into the heating appliance's power control. For example, an operating (modulation) point of the heating appliance can be controlled / applied based on a flow rate. Provided the delivery system has sufficient power reserves, such heating appliances can compensate for increased flow resistance at the flame arrestor by increasing the power consumption of the delivery system through flow rate control.

[0021] The burner can comprise at least one flat perforated plate or a cylindrical perforated plate arranged between a burner cavity and the combustion chamber. The burner cavity can be connected to the mixture channel in such a way that the combustion mixture flows from the mixture channel through the burner cavity, exits the perforated plate, and is combusted there. An ignition device can also be arranged in the area of ​​the perforated plate, configured to ignite a mass flow of combustion mixture exiting through the perforated plate. The burner can be arranged on a burner door of a combustion chamber of the heating appliance. The burner door can have a flow-through opening that connects the mixture channel of the heating appliance to the burner cavity. A cylindrical burner can have a flange for attachment to the burner door, which can be connected to the burner door, for example, by means of a screw connection.There is usually a seal, for example a high-temperature-resistant graphite seal, between the burner and the burner door.

[0022] The burner can include (at least) one flame arrestor, which is designed and arranged in the burner cavity such that the combustion mixture flowing towards the perforated plate must pass through the flame arrestor. In other words, the flame arrestor can cover the entire available flow cross-section in the burner cavity, so that the combustion mixture flowing towards the perforated plate must pass through the flame arrestor. For example, in a burner designed in a cylindrical shape, the flame arrestor can also be cylindrical with a largely constant distance to the perforated plate. Similarly, in a flat (planar) perforated plate, the flame arrestor can also be flat and planar and arranged at a distance from the perforated plate in the burner cavity.

[0023] The flame arrestor can incorporate (micro-)channels (e.g., with a channel cross-section less than 1 / 100, 1 / 1,000, or even 1 / 10,000 of the pipe's cross-section), pore systems, or honeycomb structures, etc., within its interior, which are the only structures that allow the flow of fuel gas through their cross-section. The channel density or porosity of the flame arrestor can be adapted to the flow or the fuel gas. "Channels" in this sense are, in particular, flow paths for the combustion mixture through the flame arrestor, i.e., flow paths that extend from an inlet side (facing the mixture channel) to an opposite outlet side (facing the perforated plate). The channels can have a straight or directional (sloping, winding, etc.) course.If the flame barrier is designed with porosity, this refers in particular to the (irregular) formation of interconnected pores that also allow flow from the inlet side to the opposite outlet side. Suitable materials or semi-finished products for the flame barrier are listed below as examples, and these can also be used in combination and / or composite forms: open-pored (open-cell) ceramic or metal foam, expanded metal, in particular multi-layered and / or sintered, wire mesh, in particular multi-layered, fiber mat, optionally sintered, (correspondingly high-temperature resistant) nonwoven fabric.

[0024] According to one embodiment, the burner and flame arrestor can be designed as a single unit. The burner can be connected to the burner door via a seal made of graphite or a similar material.

[0025] The heating appliance can adjust its burner output to the demand, a process also known as modulation. Upon detecting a change in heat demand, for example, by taking into account the flow and return temperatures of a heating circuit connected to the appliance, a control unit can adjust the fan output and thus the combustion air flow rate to the heat demand. Simultaneously, a control system adjusts the fuel flow rate to the changing combustion air flow rate. Often, to prevent flame flashbacks at low output levels, the combustion air ratio is adjusted, particularly by increasing the proportion of combustion air.

[0026] The heating appliance may have a gas valve to control the fuel mass flow, which typically includes a gas safety valve and a gas control valve. The gas control valve may, in particular, be a stepper motor valve capable of setting a defined fuel mass flow. The safety valve is designed to prevent the escape of unburned fuel and, for example, during the heating appliance's start-up process, is only released after the fuel delivery system has reached a starting power level suitable for the process.

[0027] According to step a), at least one parameter can be recorded that allows conclusions to be drawn about the flow resistance of the flame arrestor. The parameter to be recorded can be, in particular, a fuel flow rate, a combustion air flow rate, and / or a flow rate of a mixture thereof, or a quantity from which these can be derived, for example, operating parameters of the heating appliance's delivery system. In an automated implementation of the procedure proposed here, step a) can, for example, be carried out using a control unit of the heating appliance, and the recorded parameters can be stored in a memory (of the control unit).

[0028] Step b) involves determining the time course of a parameter recorded in step a) or a derived quantity or function. This time course can begin, in particular, with the replacement or regeneration of the flame arrestor or with the (re)installation of the heating appliance, in order to record the development of the flame arrestor's flow resistance over its operating time. Step b) also allows for automated execution, for example, on a control unit of the heating appliance, whereby the determined time course can also be stored in the control unit's memory.

[0029] According to step c), the permeability of the flame arrestor is determined based on the time course defined in step b). Reduced permeability of the flame arrestor can be detected, in particular, when at least one parameter or function increases or decreases. Step c) can also be performed automatically by a control unit of the heating appliance as part of a proposed procedure.

[0030] According to one embodiment, an evaluation of the temporal profile can be carried out as part of step c). This evaluation can include a comparison of the temporal profile or a value thereof with at least one limit value or a characteristic curve. A critically reduced flame barrier permeability can be determined when at least one limit value is reached (or exceeded). A critically reduced flame barrier permeability can be defined by a restriction of the functionality, in particular the available power range, of the heating appliance, or by a drop in the efficiency of the heating appliance below a predefined limit value. The limit values ​​or the characteristic curve can be determined in advance for a reference heating appliance in (laboratory) tests.

[0031] According to one embodiment, step a) can be performed at at least one predefined operating point of the heating appliance. This embodiment can be particularly relevant for modulating heating appliances, as it allows for easy comparison of the measured parameters. Thus, one or more operating points (frequently occurring during normal operation) can be predefined or selected for which step a) is performed.

[0032] According to an alternative configuration, at least a subset of parameter values ​​for one or more corresponding operating points can be generated from a set of recorded parameter values. A conversion based on a known fan characteristic curve would also be possible.

[0033] According to one embodiment of the proposed method, other changes during the operation of the heating appliance, which may also affect a parameter recorded in step a), can be determined and taken into account when carrying out steps b) and / or c). Such changes could include, for example, component tolerances or a change in the pressure loss of the exhaust system.

[0034] According to one embodiment, the break-in behavior of the heating device after its commissioning can be taken into account. Alternatively, the method proposed here can also be carried out only after the heating device's break-in phase has been completed following its commissioning. During the break-in phase, a steady state has not yet been established in the flow path of the heating device, which can lead to inaccuracies in at least one of the measured parameters.

[0035] According to one embodiment, if a critically reduced permeability of the flame arrestor is detected, the heating appliance can be taken out of service, put into emergency operation, and / or blocked from restarting (fault condition). A critically reduced permeability of the flame arrestor can thus lead to critical operating conditions of the heating appliance and, in particular, have negative effects on the ignition process. Putting the heating appliance into emergency operation (with power limitation) can prevent it from being taken out of service and, if necessary, from being (temporarily) blocked from restarting.

[0036] According to a further embodiment, information about the flame arrestor's permeability status, and in particular about critically reduced permeability, can be displayed via an (external or integrated) display device and / or made available for retrieval via a network, especially the internet, and / or sent as a message. For example, the information can be made available on an appliance interface of the heating appliance or on network storage (cloud). Advantageously, this allows, for instance, a user / operator of the heating appliance and / or a specialist company to be informed about the implementation of one of the proposed procedures via a message, enabling the specialist company to schedule and carry out an appointment for replacing or regenerating the flame arrestor accordingly.In particular, this allows for a quick resolution of a fault condition in the heating device.

[0037] In addition, a control unit for a heating appliance is proposed, configured to carry out a procedure proposed herein. This control unit may, for example, include a processor. In this context, the processor can execute the procedure stored in the control unit's memory. The control unit may be electrically connected to a conveying device and / or a flow sensor. Furthermore, data acquired or required during the execution of this proposed procedure can be stored in the control unit's memory, such as parameters acquired in step a), a defined time profile in step b), and / or limit values ​​or characteristic curves.

[0038] Another aspect proposed is a heating appliance designed for the combustion of a mixture of combustion air and fuel gas. This heating appliance can be a gas-fired appliance, in particular a hydrogen-powered gas-fired appliance. The gas-fired appliance can include a burner and a delivery system for supplying a mixture of fuel (hydrogen) and combustion air to the burner. The heating appliance can include a flame arrestor, which can be configured to prevent the propagation of a flame from the burner towards the mixture channel. For this purpose, the flame arrestor can, for example, be arranged parallel to a burner surface within a burner cavity, and in particular, the flame arrestor can cover the entire available flow cross-section.The heating device may also include additional means adapted to perform the steps of the method disclosed herein. These means may include a control and regulating device.

[0039] In addition, a computer program is proposed for the (at least partial) execution of a procedure presented herein on a heating device proposed herein. In other words, this specifically concerns a computer program (product) comprising commands that, when executed by a computer, cause it to carry out a procedure proposed herein. The computer program can, in particular, be executed on a control unit of a heating device proposed herein.

[0040] Another aspect that is proposed is a machine-readable storage medium on which the computer program is stored. This machine-readable storage medium is typically a computer-readable data carrier.

[0041] This document describes a method for operating a heating appliance, a computer program, a control and monitoring device, and a heating appliance itself, which at least partially solve the problems described with reference to the state of the art. In particular, the method for operating the heating appliance, the computer program, the control and monitoring device, and the heating appliance contribute to the simple and fully automated detection and correction of reduced flame arrestor permeability in a timely manner, before it can affect the functionality of the heating appliance.

[0042] Furthermore, the invention can be implemented without or with only minor structural modifications to a heating device.

[0043] The invention and its technical context are explained in more detail below with reference to the accompanying figures. It should be noted that the invention is not intended to be limited by the exemplary embodiments shown. In particular, unless explicitly stated otherwise, it is also possible to extract partial aspects of the situations described in the figures and combine them with other components and findings from the present description. It should be emphasized that the figures, and especially the depicted dimensions, are only schematic. They show: Fig. 1: a sequence of a procedure proposed here, Fig. 2: a heating device proposed here, and Figs. 3-5: parameter curves that can occur when carrying out a procedure proposed here.

[0044] Fig. 1 Figure 1 shows an exemplary and schematic representation of the sequence of a procedure proposed here. The execution of steps a), b), and c), as depicted in blocks 110, 120, and 130, can be carried out at least once in the specified order during a regular procedure. In particular, the procedure can be performed at regular intervals or at at least one predetermined operating point. The procedure serves to increase the safety of a heating appliance 1, especially one operated with hydrogen or a hydrogen-containing mixture as fuel, by enabling the timely detection of reduced or critically reduced permeability of a flame arrestor 12 of the heating appliance 1.

[0045] Fig. 2Figure 1 shows an exemplary and schematic representation of a heating device 1 proposed here. This device can include a burner 3 arranged in a combustion chamber 8. The burner 3 can have the form of a hollow cylinder, with a burner cavity formed inside. A flame arrestor 12 can be oriented parallel to or concentric with the surface of the burner in the burner cavity and cover the entire flow cross-section available in the burner cavity.

[0046] Combustion air can be drawn in via a combustion air supply 4 by a conveying device 2, in particular designed as a blower. A flow sensor 21 can be arranged in the combustion air supply 4. The conveying device 2 can be connected to a speed controller 6, which can regulate the speed n of the conveying device 2 by means of a pulse-width modulated (PWM) signal. A gas valve 5 can add fuel gas from a gas supply 14 to the drawn-in mass air flow of combustion air and may include a safety valve and a gas control valve for controlling the mass flow of fuel gas to be added. The generated mixture of fuel gas and combustion air can flow to the burner 3 via a mixture channel 11 and be ignited there by the ignition device. The burner 3 can have a cylindrical shape, the base of which can be attached to a burner door 15 in such a way that combustion mixture can flow from the mixture channel into the burner 3.The heat generated during combustion can be transferred via a heat exchanger 20 to a heating circuit 19, through whose heating flow 17 heat transfer fluid of the heating circuit 19 can be supplied and returned to the heating unit 1 via a heating return 18. After combustion, the combustion products can be discharged to the outside via an exhaust pipe 9 of the heating unit 1 and an exhaust system 10 connected to the heating unit 1.

[0047] The heating device 1 proposed here can be configured specifically for the combustion of hydrogen. Furthermore, the heating device 1 can have a flame monitoring device 13 on / in the burner door 15, which in this example is designed as a sensor for UV (ultraviolet) radiation emitted by the flame.

[0048] A control unit 7 can be configured to control the heating appliance 1. For this purpose, it can be electrically connected, for example, to the speed controller 6, the conveying device 2, the gas valve 5, the flame monitoring device 13, and a network 16 (Internet). The control unit 7 can be configured to carry out a procedure proposed here.

[0049] In block 110, according to step a), at least one parameter can be acquired that allows conclusions to be drawn about the flow resistance of the flame arrestor 12. This parameter can be selected, in particular, from: a signal from the flow sensor 21, a rotational speed n of the conveying device 2, a control signal from the speed controller 6, an electrical supply current, and / or an electrical power consumption of the conveying device 2. The acquired parameter values ​​can, for example, be stored in a memory of the control unit 7.

[0050] In block 120, according to step b), a time course of the parameter recorded in step a) (block 110), or of a quantity or function derived from it, can be determined. This can, for example, be stored in a memory of the control unit 7.

[0051] In Block 130, a reduced permeability of the flame arrestor can be determined according to step c) in view of the temporal profile determined in step b) (Block 120). For this purpose, the temporal profile can be compared with a limit value or a characteristic curve of limit values.

[0052] According to an optional step d), information about the permeability status of the flame arrestor 12, and in particular about a critically reduced permeability, about putting the heating device 1 into emergency operation or decommissioning, can be displayed via a (external or integrated into the heating device 1) display device and / or made available for retrieval via a network 16, in particular the Internet, and / or sent as a message.

[0053] Fig. 3-5The parameter profiles 22, which can occur when carrying out a procedure proposed here, are shown. In particular, various signals are shown with respect to time t, whereby the flame arrestor 12 becomes increasingly clogged over time.

[0054] Fig. 3 The figure on the left shows the speed curve of the fan of the conveying device 2, which increases over time to compensate for the increased flow resistance caused by the flame arrestor 12. Such a signal curve is to be expected, in particular, when the flow rate is controlled. The figure on the right shows the mass flow rate of the combustion air. on it , which is reduced by the flame arrestor 12 becoming clogged, in particular by the use of a speed control of the conveying device 2.

[0055] Fig. 4This again shows the increasing fan speed n with increasing soiling of the flame arrestor 12. At the same time, a (PWM) control signal PWM Fan decreases, as do the power P Fan and the supply current I Fan consumed by the pumping device 2.

[0056] Fig. 5 Figure 1 shows a parameter profile 22 of a fan speed n over time t and a profile of known changes 23 of the parameter profile 22 (here the fan speed n). From the difference, the proportion 24 of the added flame arrestor 12 of the total change in the parameter profile 22 can be determined. Reference symbol list

[0057] 1 Heating unit 2 Conveyor 3 Burner 4 Combustion air supply 5 Gas valve 6 Speed ​​controller 7 Control unit 8 Combustion chamber 9 Exhaust pipe 10 Exhaust system 11 Mixture channel 12 Flame arrestor 13 Flame monitoring 14 Gas supply 15 Burner door 16 Network 17 Heating flow 18 Heating return 19 Heating circuit 20 Heat exchanger 21 Flow sensor 22 Parameter curve 23 Known changes 24 Proportion of clogged flame arrestor

Claims

1. A method for operating a heating appliance (1) comprising a burner (3) to which a mixture of fuel gas and combustion air is supplied via a mixing duct (11) by means of a conveying device (2), and a flame arrestor (12), designed to prevent a flame from spreading from the burner (3) towards the mixture duct (11), wherein the method comprises at least the following steps: a) Detecting at least one parameter which allows an inference to be drawn regarding a flow resistance of the flame arrestor (12), this being selected from the following group: - a signal from a flow sensor (21) arranged in a combustion air supply (4) of the heating appliance (1) - a rotational speed n of a conveying device (2) designed as a fan, - the power consumption of the conveying device (2), - the supply current of the conveying device (2), - a control signal from a controller of the conveying device (2) and / or - a pressure in the flow path of the heating appliance (1) upstream and downstream of the flame arrestor (12). b) determining a temporal progression of the parameter recorded in step a) or a quantity or function derived therefrom, c) Determining the permeability of the flame barrier (12) in view of the time curve determined in step b).

2. A method according to one of the preceding claims, wherein, as part of the implementation of step c), an evaluation of the time curve is carried out, comprising a comparison of the time curve or a value thereof with at least one threshold value or a threshold value map, and a critically reduced permeability of the flame barrier (12) is detected upon reaching the at least one threshold value or the characteristic map.

3. A method according to any of the preceding claims, wherein step a) is carried out at at least one predetermined operating point of the heating appliance (1).

4. A method according to one of the preceding claims, wherein, in a step d), information regarding a permeability of the flame barrier (12) detected in step c) is displayed via a display device, and / or made available for retrieval via a network (16) or sent as a message.

5. A method according to one of the preceding claims, wherein, upon detection of a critically reduced permeability of the flame barrier (12), the heating appliance (1) is taken out of service, switched to emergency mode and / or locked to prevent restarting.

6. A method according to one of the preceding claims, wherein the determination of the temporal progression is restarted upon replacement or regeneration of the flame barrier (12).

7. Control and regulation unit (7) for a heating appliance (1) comprising a burner (3) to which a mixture of fuel gas and combustion air is supplied via a mixing duct (11) by means of a conveying device (2), and a flame arrestor (12), designed to prevent a flame from spreading from the burner (3) towards the mixture duct (11), wherein the regulating and control device (7) is designed to cause the heating appliance (1) to perform the method steps according to one of claims 1 to 6.

8. Heating appliance (1) comprising a burner (3) to which a mixture of fuel gas and combustion air is supplied via a mixing channel (11), and a flame arrestor (12), designed to prevent a flame from spreading from the burner (3) towards the mixture duct (11), and further comprising a control and regulation device (7) as per claim 7.

9. A computer program comprising instructions which, when executed by a control and regulation unit (7) of a heating appliance (1) according to claim 8, cause the heating appliance (1) to perform the method steps according to one of claims 1 to 6.

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