GB2495402A - Heating device with a heat exchanger movable between an operating position and a maintenance position - Google Patents

Abstract

The heating device comprises a housing 1, a burner 16 operationally connected to a heat exchanger 18 to heat a medium flowing through the heat exchanger, a base 34 and a movement means such as a horizontal hinge 36 that permits the heat exchanger to be moved between an operational position inside the housing and a maintenance position at least partially outside the housing. The base is fixed to the heat exchanger and, in the operational position, the base connects to the housing in a gas-tight manner to define a gas-tight space (42, figure 1) in which the heat exchanger and burner are located. In the maintenance position, cleaning of an inner side of the heat exchanger is possible. A support 48,52 may be provided on an inner side of the housing to receive the base in the operational position, the base resting on-top of the support. Ideally, the support makes a gas-tight seal with the housing and the base.

Description

Short indication: Heating Device with Pivotable Heat Exchanger The present invention relates to a heating device according to the preamble of claim 1. A heating device of this kind is used for heating a medium, such as water. The heated water will subsequent'y be used for heating spaces by passing the heated medium through one or several radiators. Alternatively, or additionally, the heated water can be used by users as hot tap water.

DE-A1-IOI.30.925 reveals a heating device for heating water. The heating device comprises a housing, a burner and a heat exchanger. In normal operation, the burner is provided on top of the heat exchanger. The flames from the relevant burner point downwards and transfer heat in the heat exchanger onto water. The heating device further comprises a base. Fixed in the base, a condense tray is provided. In the operational state, the heat exchanger rests on the condense tray, with which it forms the heat exchanger's base. The condense tray is further connected to a smoke gas outlet for disposing of the smoke gases which flow from the burner, via the heat exchanger into the condense tray. The heating device also comprises rotation means. For the purpose of maintaining the heat exchanger, it can be lifted upwards out of the condense tray and turned towards a maintenance position via the rotation means outside of the heating device housing. Thanks to this combined translation and rotation action, it is possible to inspect and/or clean the heat exchanger from underneath.

One problem of the known heating device is that it is mechanically relatively complex.

It is an aim of present invention to provide a heating device which at least partially removes the above-mentioned disadvantage, or to provide at least an alternative. In particular, it is an aim of the present invention to provide a heating device

that is simpler than those of the prior art.

The invention achieves the aim by a heating device according to claim 1.

Advantageous embodiments are defined in the dependent claims.

A heating device comprises a housing, a burner, a heat exchanger. a base and movement means. The burner is operationally connected to the heat exchanger for heating a medium that flow's through the heat exchanger. The movement means connect the heat exchanger movably with the housing to move between an operational position inside the housing and a maintenance position at least partially outside of the housing.

In the operational position, the base seals onto the housing in a gas-tight manner to limit a gas-tight space inside the housing, in which gas-tight space at least the burner and the heat are found. The heat exchanger is provided in a fixed manner to the base. The base is connected to the housing by the movement means in such a way that the heat exchanger and the base are together movable between the operational position and the maintenance position.

Thanks to the invention, the heat exchanger can move between the operational position and the maintenance position in a simple manner, without requiring a succession of two different actions, such as the translation and rotation action in the

prior art.

In particular, the heating device further comprises a passage element which is connected to an inner side of the housing in a gas-tight and fixed manner and comprises at least a passage hole for passing a line to the gas-tight space, where the base comprises a gap corresponding with the passage element, and the base seals to the passage element in the operational position in order to together limit the gas-tight space inside the housing. A rigid line to the gas-tight space can be passed through this without hindering the base's movability.

In one embodiment, the heating device further comprises a support, this support being provided on an inner side of the housing and arranged to receive the base in the operational position. A support of this kind enables a simple and reliaNe support of the movable base.

In particular, the passage element and the support have been formed as one component. This reduces the number of points between the gas-tight space and the other space in the housing which must be sealed in a gas-tight manner.

In one embodiment, the heat exchanger is provided on the base and supports the base in the operational position on the support. As a result, the heat exchanger rests onto the support via the base, making both supporting and sealing the base in relation to the housing in a gas-tight manner easier.

In one advantageous embodiment, the support will solely have a force-transferring connection to a front andlor rear side of the housing. This enables a smooth side of the housing.

In one embodiment, the heating device further comprises a gas-tight support seal that spans between the support and the housing. An independent gas-tight support seal of this kind makes it possible to choose optimum materials for the gas-tight support seal and the support.

In one advantageous embodiment, the heating device further comprises a gas-tight base seal that spans between the support and the base in the operational position.

An independent gas-tight base seal of this kind makes it possible to choose optimum materiaL for the gas-tight base seal and the support.

In one embodiment, the movement means comprise a hinge to pivotably connect the base onto the housing. Pivoting around a hinge is a constructively simple manner to make the base movable.

In particular, the hinge is provided to the front of the housing and comprises an essentially horizontal hinge axis. This moves the centre of gravity of the base with heat exchanger upwards when the heat exchanger is moved to the maintenance position, and downwards when returning it to the operational state. This enables a simple gas-tight support of the base in the housing.

The invention further relates to a method for maintaining a heating device in accordance with the relevant independent claims. A method of this kind is a simple manner of maintaining the heating device, while after returning the base with the heat exchanger to the operational position, a gas-tight space is created.

The invention also relates to the foflowing aspects, which are advantageous both separately and combined with the aspects mentioned above.

A heating device comprises a housing, a burner, a heat exchanger, and a hinge, where -The burner is operationally connected to the heat exchanger for heating a medium that flows through the heat exchanger, -The housing comprises a housing opening to a front side of the heating device, -The hinge pivotably connects the heat exchanger to the housing and defines an essentially horizontal pivoting axis to pivot the heat exchanger through the housing opening between an operational position inside the housing and an assembly position at least partially outside of the housing, where -The hinge comprises a hinge support and a hinge pin with a diameter D, -The hinge support comprises a hinge hole with a minimum diameter D for rotatably supporting the hinge pin, and -The hinge support comprises an entry opening, this ently opening, in a plane perpendicular to the hinge axis, having a width B1 that is greater than D and interrupts the hinge support to provide a continuous connection for receiving the hinge pin in a direction perpendicular to the hinge axis and guiding it to the hinge pin hinge hole.

Thanks to the invention, the heating device can be assembled in a simple manner, as the heat exchanger can be hung into the housing in one go. As hinge support and hinge pin are already present. no further connection actions are required at the time of hanging. Thanks to the invention, it is even possible to already connect one or several components, such as the burner, fan. andior lines to the heat exchanger before it is hung.

Movements, such as receiving and guiding the hinge pin, in directions perpendicular to the pivot axis here mean any movement that is essentially fully in a plane perpendicular to the pivot axis. The direction of the movement is not required to cross with the pivot axis and the movements may take place along any type of line, including a straight or curved line. Of importance is that there is no substantial component of the movement in a direction parallel to the pivot axis.

Preferably, the hinge hole has a length, in a plane perpendicular to the pivot axis, that is greater than B and the hinge hole, with the heat exchanger in the operational position, spans lengthways at least partially into a vertical direction.

Preferably, the hinge support limits, in a plane perpendicular to the pivot axis and with the heat exchanger in the operational position, the hinge hole at the hinge pin location fully in horizontal direction. This prevents the hinge connection between the heat exchanger and housing, after the heat exchanger has been brought into the operational position, from unintentionally becoming loose.

In one embodiment, the hinge support limits, in a plane perpendicular to the pivot axis and with the heat exchanger in the assembly position, the hinge hole at the hinge pin location fully in horizontal direction. This prevents the hinge connection between the heat exchanger and housing, after the heat exchanger has been hung in the operational positions, from unintentionally becoming loose.

In one advantageous embodiment, the entry opening is pointed to the front of the heating device with the operational position of the heat exchanger. If the hinge support is provided to the housing, this means that the entry opening points to the front, so that the heat exchanger with hinge pin can be received in a simple manner. If the hinge support is provided to the heat exchanger, this means that the entry opening can be pointed to the housing with hinge pin by hanging the heat exchanger into the housing in a pivoted position, for example almost upside down.

In one embodiment, the hinge hole, in a plane perpendicular to the pivot axis.

has an elongated shape with a width B that is essentially equal to D and a length of at least twice D. Essentially equal here means that width B is just sufficient to movably take the hinge pin, i.e. the hinge pin can slide through the hinge hole lengthways of the hinge hole and the hinge pin can rotate along its longitudinal axis in the hinge hole.

Thanks to the possibility of sliding, the hinge pin can slide inside the hinge hole to a position that is removed from the entry opening.

In one advantageous embodiment, the entry opening forms the continuous connection essentially halfway the hinge hole, at a plane perpendicular to the pivot axis.

As a result, the hinge support forms little ridges at both sides of the entry opening that limit the hinge hole at both of its ends. These ridges prevent the hinge pin and the hinge support from unintentionally becoming loose from one another when the hinge pin is at one, or precisely the other end of the hinge hole.

In one embodiment, the hinge support is connected to the heat exchanger in a fixed manner and the hinge pin is connected to the housing. This causes the hinge support to rotate while pivoting, thus also changing the orientation of the entry opening.

Thus the entry opening can be positioned in the hinge support, which is pointing to the hinge pin while the heat exchanger is hung, while the entry opening points downwards while pivoting the heat exchanger, minimising the chance that the hinge pin touches the hinge opening via the entry opening.

In one advantageous embodiment, the heating device further comprises a base, this base sealing a gas-tight space inside the housing in a gas-tight manner in the operational position. in which gas-tight space at least the burner and the heat exchanger are found, where the heat exchanger is provided in a fixed manner to the base, and the base being connected to the heat exchanger by the hinge in such a way that the heat

S

exchanger and the base are together pivotable between the operational position and a maintenance position or the assembly position. Thus the heat exchanger can be moved between the operational position and the maintenance position or assembly position in a simple manner, without a succession of two different actions being required.

In particular, the heating device further comprises a passage element which is connected to an inner side of the housing in a gas-tight and fixed manner and comprises at least a passage hole for passing a line to the gas-tight space, where the base comprises a gap corresponding with the passage element, and the base seals to the passage element in the operational position in order to together limit the gas-tight space inside the housing. A rigid line to the gas-tight space can be passed through this without hindering the base's movability.

In one embodiment, the heating device further comprises a spacer that forms a connection between the housing and the heat exchanger for limiting the pivotability of the heat exchanger in relation to the housing. Thus the heat exchanger can be brought into the maintenance position in a simple manner, in which the heat exchanger can be cleaned in a simple manner.

The invention further relates to a method for assembling a heating device. The method comprises the following steps, carried out in the order indicated: -Providing a housing, a burner, a heat exchanger, and a hinge. where the hinge compnses a hinge support with hinge hole and a hinge pin and defines a horizontal pivot axis, -Moving the heat exchanger towards the housing. in a direction perpendicular to the pivot axis, where the heat exchanger is in a pivoted position in relation to an operational position of the heat exchanger inside the housing, -Receiving the hinge pin during the last part of the perpendicular movement in the hinge hole, -Pivoting the heat exchanger around the hinge into a maintenance or the operational position.

This is a simple manner of assembling, as the heat exchanger is hung into the housing in one go. As the hinge support receives the hinge pin during the last part of the movement, no further connection actions are required at the time of hanging. Thanks to the invention, it is even possible to already connect one or several components, such as the burner, fan, andlor lines to the heat exchanger before it is hung.

In one advantageous embodiment, the heat exchanger is pivoted by more than 900 and less than 1800 in relation to the operational position during movement. Thus it is possible to hang the heat exchanger into a housing.

In one preferable embodiment, the hinge hole and the hinge pin move vertically in relation to one another while the hinge pin is received into the hinge hole. Thus the hinge pin cannot, or at least not easily, become loose from the hinge hole during the pivoting action that follows hereafter.

Iii one advantageous embodiment, the hinge pin moves, while pivoting the heat exchanger around the hinge towards an operational position, from a first end of the hinge h&e to a second end of the hinge hole, this second end being located opposite the first end. Advantageous is that the hinge pin in the first end cannot, or at least not easily, become loose from the hinge hole, and that the hinge pin cannot, or at least not easily, become loose after pivoting, as it has then been moved to the second end.

In one preferable embodiment, a step follows of attaching a spacer between the housing and the heat exchanger. after pivoting the heat exchanger around the hinge to the maintenance or operational position. This spacer ensures that the heat exchanger can subsequently pivot in a simple and safe manner between the operational position and the maintenance position.

The invention will be further explained by an embodiment that is shown in the accompanying drawing, where: Fig. I shows a spatial view through a heating device according to the invention; Fig. 2 shows a detail of a cross section of the heating device according to the invention; Fig. 3 shows the view of Fig. 1, where the smolce gas outlet has been removed; Fig. 4 shows the view of Fig. 1, with a heat Hock pivoted to a maintenance position; Fig. 5 shows the view of Fig. 4 where the burner and gas supply have been removed; Fig. 6 shows the heating device according to Fig. 5; Fig. 7 shows the heating device according to Fig. 5 in a top view; Fig. 8 shows a detail of a hinge in the position of the heating device according to

B

Fig. 5; Fig. 9 shows a heating device with the heat block in an assembly position; Fig. 10 shows the assembly position in side view.

Fig. 11 shows a hinge in the assembly position of Fig. 9; and Fig. 12 shows the hinge of Fig 11 with bolt removed.

Fig. I shows a heating device according to the invention that is entirely indicated by reference number 1. Heating device 1 is a wall-hung central heating tank in this case, which is hung onto a wall by its rear side. Heating device I comprises a housing 2 that has been made from a set piece of metal plate material in this case. Housing 2 has a housing opening 3 to the front side of heating device 1. Heating device I further comprises an air supply 4 for the purpose of combustion air and a combustion gas supply line 6. Combustion gas supply line 6 comprises a first pipe part 8, a safety valve 10, and a gas hose 12. Air supply 4 and gas hose 12 both lead to a fan 14, where gas and air are mixed. An outlet of fan 14 is connected to a burner 16 which together form a heat block 20 with a heat exchanger 18 (see Fig. 4).

At an underside, heat exchanger 18 is continuously connected to a combustion gas outlet 24 via a condense collector 22 (Fig. 1). Combustion gas outlet pipe 24 is continuously connected to a combustion gas s-bend 26 that leads to a connection opening 28 provided at a top side of housing 2.

Connection 28 is a concentric double-walled connection of which a circular opening part 30 located inside functions as a connection opening for smoke gases and a ring-shaped opening part located outside that is meant as a combustion air supply opening 32.

Heating device I also comprises a base. The base, a base plate 34 in this case, is connected to housing 2 in a gas-tight manner in the normal operational position of Figs. 1 -3, as will be explained further, among other things, by Fig. 2. Heat exchanger 18 is provided onto base 34, in this embodiment example via condense collector 22. Heating device I is further provided with movement means, here in the form of a left hinge 36 and a right hinge 38. Hinge 36 comprises a left hinge support 39 and a hinge pin 40 that is formed by a bolt in this case, which is connected to a side of housing 2. 1-linge pin 40 has a diameter D at the location of the hinge support; the head of the bolt has a greater diameter than D of course. The longitudinal axis of hinge pin 40 defines a pivot axis 41.

Left hinge support 39 spans downwards from base plate 34 to the front side left. Right hinge 38 comprises similar components as left hinge 36. Left hinge 36 and right hinge 38 are found in the operational position as shown in Fig. 1 below base plate 34 near a front edge of base plate 34. Base plate 34 splits an inner space inside housing 2 into a gas-tight space 42 and an open space 44 located below.

The beanng gas-tight connection between base plate 34 and housing 2 is formed by a support, here a base plate support part 46 (see Figs. 6 and 9 among other ones).

Base plate support part 46 compnses a left support strip 48, a passage element, here in the form of a passage plate 50, a support strip 52 located behind, and a right support strip (not visible in the views shown). A detail section through support strip 52 located behind and base plate 34 is shown in Fig. 2. Support strip 52 located behind has an m-shaped cross section. Base plate support part 46 is fully formed as an injection moulded part made from plastic polymer. a thermoplastic co-polymer in this case, in particular Acrylonitrile-Butadiene-Styrene (ABS). ABS is a material that holds its shape and has a slight tendency to creep, making it suitable as a material for a support. Support strip 52 located behind, and with that also a substantial part of entire base plate support 46, leans on a rear side of housing 2 via inwards dented parts of a rear wall of housing 2. To the front side, base plate support 46 is connected to housing 2 via a screw connection (not shown). For the rest, base plate support 46 is not connected to housing 2 in a bearing manner. In other words, base plate support 46 leans on housing 2 via the screw connection on the left and right front sides of housing 2, as well as via support 54.

Support strip 52 located behind is provided with bearing ridges 56 that are arranged and positioned to receive the weight of base plate 34. Base plate support 46 is connected to a sealing strip 58 in a gas-tight manner. In the cross section of Fig. 2, sealing strip 58 is shown in its relaxed state. When the base plate support is mounted, as shown in Fig. 2, then sealing strip 58 will of course be positioned against an inner side of housing 2. In this embodiment example, sealing strip 58 is made from a p'astic polymer, in particular an elastomer, in this embodiment example Ethylene-Propylene-Diene Monomer (EPDM).

Base plate support 46 is further provided with a rubber sealing profile 60, in this case a sealing profile with an 0-shaped cross section. Rubber sealing profile 60 spans to the top side of base plate support 46 near an inner edge of this. Rubber retains its spring force and sealing effect when it is pressed in repeatedly. In the operational position of figs. I -3, base plate 34 rests its weight and the weight of any components mounted onto it, including heat block 20 and condense collector 22, onto housing 2 via ridges 56 and base plate support 46 on the one hand, and in particular its rear support strip 52. On the other hand, base plate 34 leans with the above-mentioned weight onto housing 2 via hinges 36, 38. Base plate 34 is connected to housing 2 in a gas-tight manner via rubber sealing strip 60, base plate support 46, and sealing strip 58.

Base plate 34 is provided with holes 61 through which lines span (not shown) for the supply or outlet of cold and hot water to and from heat exchanger 18. The lines in question are flexible enabling base plate 34 to hinge around hinges 36, 38. Passage plate 50 comprises passage holes 62 for a low-voltage cable tree (not shown), a high-voltage cable tree and gas line 8. Advantageous about passage plate 50 and passage openings 62 is that they are fixed in relation to housing 2 and do not move along when base plate 34 moves outwards. Thus the cable trees and gas line in question can be rigid and do not require any clearance.

Fig. 12 clearly shows that hinge support 39 is provided with a hinge hole 64 of an elongated shape with a length L that is greater than width B. Hinge hole 64 is furthermore open outwards via an entry opening, or gap 66 in hinge support 39. Gap 66 thus makes it possible for base plate 34 with pre-mounted components such as heat exchanger i8, to be hung onto housing 2 in an action via hinge pins 40 KFig. II). For that purpose. gap 66 interrupts hinge support 39, and 66 forms a continuous connection to hinge hole 64. This continuous connection has a width equal to width B1 of gap 66 seen in a plane perpendicular to hinge pin 40. B and B are a little greater than diameter D of hinge pin 40, so that it can be moved through gap 66 and hinge hole with some clearance. A little greater here means that the clearance is more than 1% and less than 20%, in particular less than 10%. more in particular less than 5% of D. Thanks to the elongated shape of hinge hole 64, and the fact that width B1 of gap 66 is smaller than length L of elongated hole 64, base plate 34 hangs in elongated hinge hole 64 without the risk that it falls out forwards. During hanging, hinge pin 40 moves in a direction perpendicular to its own longitudinal axis 41 through gap 66 into hinge hole 64. Next, hinge pin 40 moves in longitudinal direction of hinge hole 64 until it is at the top in hinge hole 64. In other words, hinge support 39 now hangs onto hinge pin 40.

As hinge pin 40 has moved away from gap 66 in hinge hole 64, it is now in a position of hinge hole 64 where hinge support 39 limits hinge hole 64 fully in horizontal direction.

After hanging, base plate 34 is hinged upwards from the assembly position to the S operational position of Figs. 1 -3. or the maintenance position of Figs. 4-8. Thus heat exchanger 2 moves through housing opening 3. During this pivoting upwards, hinge pin 40 moves in longitudinal direction of hinge hole 64 through hinge h&e 64 from a first end 68 of hinge hole 64 until it is its at other end 70, where hinge support 39 again limits hinge hole 64 fully in horizontal direction, so that hinge support 39 cannot unintentionally become loose from hinge pin 40 in this position either. Next, heat exchanger 1 8 is connected to the rear side of housing 2 through spacer 72. so that in normal operation, it cannot hinge further out of housing 2 than the maintenance position. Spacer 72 comprises two parts that are hinges connected to one another. One end of spacer 72 is connected to housing 2 in a hinging manner and another end of spacer 72 is connected to heat exchanger 18 in a hinging manner. If spacer 72 fails, and during assembly position work, base plate 34 cannot easily fully fall out of the housing, thanks to the previously mentioned elongated shape of hinge hole 64 and the positioning of gap 66 in relation to this hole 64, as shown in Fig. 12. Here it is of importance that the hinge support limits the hinge hole at the location of the hinge pin fully in horizontal direction, both in the operational position, in the maintenance position, and in the assembly position.

In normal operation, all components in housing 2 are provided such as for example shown in Fig. 1. Here the previously mentioned not-shown lines and cable trees are present again of course, as well as a door or cover (not shown) to the front side of housing 2. In the case of maintenance, the not-shown front side of housing 2 is removed and smoke gas outlet 24 can also be removed. Thus the state of Fig. 3 is created. Next, base plate 34, with heat block 20 present on it, including burner 16 and fan 14, can be moved to a maintenance position, such as shown in Fig. 4. In this maintenance position, burner 16 and fan 14 can be removed, thus creating the state of Fig. 5. In this state, the internal part of heat exchanger 18 can be inspected and cleaned, as can be seen in the top view of Fig. 7. In the maintenance position, base plate 34 hangs safely in left and right hinges 36. 38 thanks to elongated hinge opening 64 and hinge pin 40, as demonstrated in Fig. 8. Here, further pivoting is restr cted by spacer 72.

Within the scope of the invention, many variations are possible. Thus a heating device other than a central heating device may also achieve the advantages of the invention, such as a hot water device. Although a gas-fuelled burner is habitual at the moment, other fuels, in particular fluid fuels, are also possible. Media other than water are also heatable in a heat exchanger.

In addition to hinging movement means, other movement means, including linear movement means, for example telescopic extension means, or sliding tools, are also possible in the scope of the invention. Instead of a base plate, a base can ako be formed in another manner and from other materials such as other plastics or metal.

Here, the base does not need to be plate-shaped and can form a greater or a smaller part of the gas-tight separation inside the housing. In other words, the base plate support can form a greater part of the gas-tight separation inside the housing. Instead of two hinges, one hinge can also be provided, for example with an axis that spans from the one side of the housing to the other. More than two hinges are also possible.

The base plate support can also be formed from another plastic or a metal, or another material than described above. The metal housing can also be formed from a plastic. Within the scope of the invention, the base plate support can also be formed integrally with the housing, for example when it is formed as an injection mould pail from plastic.

The hinge can also be embodied differently. The hinge support with hinge hole and entry opening can be connected to the housing in a fixed manner, while the hinge pin is connected to the heat exchanger. In this case, hinge h&e and entry opening do not together need to define a T-shape, such as in the embodiment example shown, but can be a common continuous opening that spans at least partially vertically and where the entry opening points to the top side, or the front side, of the heating device. Thus, the hinge pin will reach the underside of the hinge hole via the entry opening. where it is limited in horizontal direction by the hinge support, so that the hinge pin cannot unintentionally come away from the hinge support here. While the heat exchanger is pivoted upwards, in this variation of the invention, the hinge pin will not move verticafly through the hinge hole, but will remain below in this hinge hole.

Claims (1)

1. <claim-text>CLAIMS1. A heating device comprising a housing (1), a burner (16), a heat exchanger (18), a base (34) and movement means where the burner (16) is operationally connected to the heat exchanger (18) to heat a medium that flows through the heat exchanger (18), the movement means (36, 38) movably connect the heat exchanger (18) with the housing (2) to move between an operational position inside the housing (2) and a maintenance position at least partially outside of the housing (2), and in the operational position, the base (34) connects to the housing (2) in a gas-tight manner to limit a gas-tight space (42) inside the housing (2), in which gas-tight space (42) at least the burner (16) and the heat exchanger (18) are found, characterised in that the heat exchanger (18) is provided to the base (34) in a fixed manner, and the base (34) is connected to the housing (2) by the movement means (36, 38) in such a way that the heat exchanger (18) and the base (34) are together movable between the operational position and the maintenance position.</claim-text> <claim-text>2. A heating device according to claim 1. further comprising a passage element (50) which is connected to an inner side of the housing (2) and at least a passage hole (62) in a gas-tight and fixed manner to pass a line to the gas-tight area (42), where the base (34) comprises a gap that corresponds with the passage element (50), and the base t34) seals to the passage element (50) in the operational position in order to together limit the gas-tight area inside the housing (2).</claim-text> <claim-text>3. A heating device according to one of the preceding claims, further comprising a support (48, 52), this support (48, 52) being provided to the inner side of the housing (2) and ranged to receive the base (34) in the operational position.</claim-text> <claim-text>4. A heating device according to daims 2 and 3, where the passage element (50) and the support (48, 52) are formed as one component (46).</claim-text> <claim-text>5. A heating device according to any of claims 3-4, where the heat exchanger (18) is provided on the base (34) and the base (34) leans on the support (48, 52) in the operational position.</claim-text> <claim-text>6. A heating device according to any of claims 3-5. where the support (48, 52) soldy has a force-transferring connection to a front andlor rear side of the housing (2).</claim-text> <claim-text>7. A heating device according to any of claims 3-6, further comprising a gas-tight support seal (58) that spans between the support (48, 52) and the housing (2).</claim-text> <claim-text>8. A heating device according to any of claims 3-7. further comprising a gas-tight support seal (60) that spans between the support (48, 52) and the base (34).</claim-text> <claim-text>9. A heating device according to any preceding claim, where the movement means comprise a hinge (36, 38) for pivotaNy connecting the base (34) to the housing (2).lO. A heating device according to claim 9, where the hinge (36, 38) is provided to the front side of the housing (2) and comprises an essentially horizontal hinge axis.II. A method for maintaining a heating device according to any preceding claim, comprising the steps of: moving the base (34) with the heat exchanger (18) into the maintenance position, cleaning an inner side of the heat exchanger (1 8), and moving the base (34) with heat exchanger (1 8) back into the operational position.</claim-text>