GB2367351A

GB2367351A - Wall mounted boiler flue and flue guard fixing arrangement

Info

Publication number: GB2367351A
Application number: GB0020129A
Authority: GB
Inventors: John Frederick Michae Bosworth
Original assignee: Heating World Group Ltd
Current assignee: Heating World Group Ltd
Priority date: 2000-08-17
Filing date: 2000-08-17
Publication date: 2002-04-03
Anticipated expiration: 2020-08-17
Also published as: GB2367351B; GB0020129D0

Abstract

A domestic boiler having a substantially vertical back-plate 17 provided with a flue gas exit orifice 19 is mounted on a wall 18 by providing a generally horizontal hole 20 through the wall for receiving a flue pipe 10 and then mounting the boiler on the wall 18 with the flue gas exit orifice 19 in the back-plate in register with the pre-formed hole 20. A flanged flue pipe 10 is inserted from the front of the boiler into the hole in the wall, through the back-plate exit orifice and is secured in position by means of a screw-threaded fastener 12 passing through the flue pipe and engaging the flanged boiler-end of the flue pipe and also a flue pipe guard 22 provided at the other end of the pipe. Sealing agent 21 may be used between the flange 11 of the flue pipe and the back-plate 19.

Description

WALL-MOUNTED BOILERS

This invention relates to methods of installing wall-mounted boilers suitable for use as domestic central heating and hot water boilers. This invention also relates to a kit of parts for mounting a boiler on a wall.

In order to optimise the utilisation of space in a constricted area such as a kitchen of a modern house, it is now a common practice to mount a boiler for the domestic central heating and hot water directly on an external wall, above ground level. This often simplifies the pipe runs and also allows the floor space beneath the boiler to be used by something which has a greater front-to-back depth than the boiler itself-for example, a floor-standing cupboard unit.

A problem associated with the mounting of a boiler on a wall is that the connection of a flue pipe to the boiler may not be straightforward, especially if the boiler is mounted relatively high on the wall. The conventional practice is to provide a flue gas exit on a top plate of the boiler and to employ a verticallyextending flue pipe which connects externally to the top plate, in register with the flue gas exit. The flue pipe must then turn through a significant angle in order to pass through the wall on which the boiler is mounted. The verticallyextending part of the flue pipe, from the boiler, means that the boiler must be mounted a significant distance from the ceiling or from some other obstruction above the boiler.

A solution to the above problems associated with the connection of a flue pipe to a wall-mounted boiler has been proposed in our prior British Patent Specification No. GB-2323914-A. In this specification, we have described and claimed the provision of a wall-mounted boiler having a back-plate with a flue gas exit orifice, the boiler being mounted on a wall with that orifice in register

with a hole pre-formed through a wall. Then, a flanged flue pipe is inserted through the orifice in the back-plate into and through the hole in the wall, until the flange engages the back-plate. The joint between the flange and the backplate is then sealed with fire resistant cement and secured with mechanical fasteners. The installation is completed by cutting off the excess flue pipe projecting from the external surface of the wall, and mounting a mesh flue guard over the end of the pipe.

Though the arrangement described in our prior Specification No.

GB-2323914-A is successful, it is nevertheless time consuming to install effectively. Further, the mechanical fasteners used to secure the flange of the flue pipe to the back-plate of the boiler can be difficult to install, in view of the relatively constricted space of the partially-built boiler on the back-plate. Also, those mechanical fasteners encroach on the space to be occupied by the heat exchanger and at times can obstruct a proper installation of that heat exchanger.

The present invention aims at improving the system described in our prior Specification No. GB-2323914-A, further to simplify the installation of a flue pipe for a wall-mounted boiler.

According to a first aspect of the present invention, there is provided a method of installing a wall-mounted boiler having a substantially vertical backplate provided with a flue gas exit orifice therein, which method comprises the steps of: - providing a generally horizontal hole through the wall, for receiving a flue pipe;

- mounting the boiler to the wall with the flue gas exit orifice in the backplate in register with the hole in the wall ; - inserting from the front of the boiler a flanged flue pipe through the flue gas exit orifice to enter the hole in the wall ; - positioning a flue pipe guard over the external end of the flue pipe projecting from the external surface of the wall ; - passing a screw-threaded clamping device through the flue pipe which device has respective engagement means at its two ends, to engage the flanged end of the flue pipe at the inner end of the clamping device and the flue pipe guard at the outer end of the clamping device; and - tightening the clamping device so as to hold the flange of the flue pipe to the back-plate of the boiler at the inner end thereof and to hold the flue pipe guard to the wall at the outer end thereof.

According to a second, but closely related, aspect of the present invention, there is provided a kit of parts for the mounting of a boiler on a wall, which kit of parts comprises: - boiler apparatus having a substantially vertical back-plate provided with a flue gas exit orifice therein and adapted for mounting on a wall having a pre-formed generally horizontal flue pipe hole formed therethrough with the orifice in register with said hole ; - a flanged flue pipe for insertion from the front of the boiler through the flue gas exit orifice to enter the hole in the wall ; - a flue pipe guard for positioning over the external end of the flue pipe projecting from the external surface of the wall ; and

- a screw-threaded clamping device having respective engagement means at its two ends, to engage the flanged end of the flue pipe at the inner end of the clamping device and the flue pipe guard at the outer end thereof, whereby on installation the clamping device is passed through the flue pipe so that on subsequent tightening thereof the flange of the flue pipe is held to the back-plate of the boiler at the inner end of the clamping device and the flue pipe guard is held to the wall at the outer end of the clamping device.

It will be appreciated that with the method of this invention and also the kit of parts, the installation of a wall-mounted boiler is much simplified, even as compared to the arrangement of GB-2323914-A. No longer is it necessary for separate operations to be performed firstly to secure the flue pipe to the backplate of the boiler and secondly to secure a guard over the external end of the flue pipe. Rather, both operations may be completed in one simple step, using the screw-threaded clamping device. Thus, to complete the flue pipe arrangement, all that is necessary is for the fitter to insert the clamping device through the flue pipe so that the inner end thereof engages the flue pipe flange, and then (from the outside) furnish a suitable flue pipe guard over the flue pipe, and tighten the clamping device. This then simultaneously secures the flue pipe to the back plate and also the flue pipe guard to the wall.

In order to prevent leakage of flue gases from the joint between the flange and the back-plate, a sealing agent-such as fire cement-should be applied to the joint, before the flange is pressed home against the back-plate. Such a sealing agent may be applied around the flange before the flue pipe is inserted into the hole through the wall, or may be applied to the back-plate, around the orifice therein, or to both mating surfaces. Another possibility would

be to slip a gasket over the flue pipe before the flue pipe is inserted into the hole in the wall.

The screw-threaded clamping device preferably comprises a simple rod of metal, provided at its inner end with a spider to engage the flange of the flue pipe and at its outer end with threads, whereby a washer and nut may be fitted to the rod, after it has been passed through a hole in the flue pipe guard.

Depending upon the installation site, the nut could be a conventional hexagonal nut, a wing nut or a security nut adapted to resist unauthorised removal.

For the preferred form of clamping device discussed above, the spider may comprise a cross-bar with the rod secured centrally thereto, such that the bar lies at right angles to the length of the rod. The ends of the bar may be profiled to facilitate centralisation of the bar in the open flanged end of the flue pipe when tension is applied to the rod by means of the nut threaded on to the outer end of the rod.

The guard may be essentially conventional, though in order to accommodate the load imparted thereto by tightening the screw-threaded clamping device, it may be necessary to make the guard of thicker or stronger materials. In addition, the load may be spread over a relatively large area of the guard by providing a loading plate through which the clamping device passes.

By way of example only, the boiler installation method of this invention will now be described in greater detail, reference being made to the accompanying drawings, in which: Figure 1 shows a flue pipe together with a clamping device for use in the installation method;

Figure 2 shows the flue pipe and clamping device of Figure 1 at the first stage of the performance of the installation method ; Figure 3 shows the flue pipe installed in a boiler with the clamping device passing therethrough; Figure 4 is a diagrammatic vertical section through a wall on which a boiler has been installed; and Figure 5 diagrammatically shows the external surface of the wall following the completion of an installation.

Referring initially to Figure 1, there is shown a flue pipe 10 having a flange 11 provided at one end. The flange could be separately formed and secured to the main part of the pipe, or could be formed integrally with the pipe.

To give the flue pipe the required corrosion resistance, it may be made of stainless steel, or mild steel with a vitreous enamel coating. Also shown in Figure 1 is a clamping bolt 12 having threads 13 formed along one end portion and at its other end having a cross-bar 14 secured thereto. The cross-bar 14 is disposed symmetrically with respect to bolt 12 and has chamfered edges as shown at 15, to facilitate the location of the cross-bar in the flue pipe 10, with the bolt extending co-axially. A wing nut 26 is engageable with the threads 13.

Figure 2 diagrammatically shows a boiler 16 having a back-plate 17 by means of which the boiler is mounted on a wall 18 (Figure 4). The back-plate 17 has a circular orifice 19 which registers with a pre-formed hole 20 formed through wall 18, so that the flue pipe 10 may be inserted through the orifice 19 and hole 20, from within the boiler 16, before the heat exchanger is mounted therein. As shown in Figure 2, fire cement is applied at 21 around the joint between the flange 11 and the flue pipe 10 before the pipe is inserted into the

hole 20 through the wall 18, in order that when the flue pipe 10 is pushed fully home against the back-plate 17 (Figure 3) an effective gas-tight seal is achieved between the flange 11 and the back-plate 17. The clamping bolt 12 is then pushed through the flue pipe 10, so that the bar 14 locates centrally in the open flanged end of the flue pipe 10, with the threaded portion 13 projecting externally of the wall 18.

From outside, the length of the projecting portion of the flue pipe 10 is trimmed if necessary so as to give approximately 20mm projecting from the outer surface of the wall 18. The length of the flue pipe 10 could of course be trimmed before the flue pipe is pushed into the hole 20 in the wall 18. Then, a flue guard 22 constructed from metallic rods welded together so as to have the general shape of a basket is placed over the projecting portion of the flue pipe 10, with the threaded portion 13 of bolt 12 extending between the bars of the flue pipe guard 22. A load-spreading plate 23 is passed over the threaded portion 13 of the bolt 12 to engage the bars of the guard 22 and wing nut 26 is fitted thereto. The nut 26 is tightened sufficiently to pull the flange 11 fully home against the back-plate 17 of the boiler. That force is also sufficient to keep the flue guard 22 in its required position, as shown in Figure 5. Finally, the threaded end of the bolt 12 projecting beyond wing nut 26, is sawn off, so completing the installation.

Claims

1. A method of installing a wall-mounted boiler having a substantially vertical back-plate provided with a flue gas exit orifice therein, which method comprises the steps of: - providing a generally horizontal hole through the wall, for receiving a flue pipe; - mounting the boiler to the wall with the flue gas exit orifice in the backplate in register with the hole in the wall ; - inserting from the front of the boiler a flanged flue pipe through the flue gas exit orifice to enter the hole in the wall ; - positioning a flue pipe guard over the external end of the flue pipe projecting from the external surface of the wall ; - passing a screw-threaded clamping device through the flue pipe which device has respective engagement means at its two ends, to engage the flanged end of the flue pipe at the inner end of the clamping device and the flue pipe guard at the outer end of the clamping device; and - tightening the clamping device so as to hold the flange of the flue pipe to the back-plate of the boiler at the inner end thereof and to hold the flue pipe guard to the wall at the outer end thereof.

2. A method as claimed in claim 1, wherein a sealing agent is applied to the joint between the flange and the back-plate before the flange is pressed home against the back-plate.

3. A method as claimed in claim 2, wherein the sealing agent comprises a fire cement.

4. A method as claimed in claim 1, wherein a gasket is fitted over the flue pipe before the flue pipe is inserted into the hole in the wall.

5. A method as claimed in any of the preceding claims, wherein the screwthreaded clamping device comprises a metal rod provided at its inner end with a spider to engage the flange of the flue pipe and at its outer end with threads, whereby a washer and nut may be fitted to the rod, after it has been passed through a hole in the flue pipe guard.

6. A method as claimed in claim 5, wherein the nut comprises one of a wing nut or a security nut adapted to resist unauthorised removal.

7. A method as claimed in claim 6, wherein the spider comprises a crossbar with the rod secured centrally thereto, such that the bar lies at right angles to the length of the rod.

8. A method as claimed in claim 7, wherein the ends of the bar are profiled to facilitate centralisation of the bar in the open flanged end of the flue pipe when tension is applied to the rod.

9. A method as claimed in any of claims 5 to 8, wherein the washer comprises a load-spreading plate engageable with the flue guard.

10. A method as claimed in claim 1 and substantially as hereinbefore described with reference to the accompanying drawings.

11. A kit of parts for the mounting of a boiler on a wall, which kit of parts comprises: - boiler apparatus having a substantially vertical back-plate provided with a flue gas exit orifice therein and adapted for mounting on a wall having a pre-formed generally horizontal flue pipe hole formed therethrough with the orifice in register with said hole ;

- a flanged flue pipe for insertion from the front of the boiler through the flue gas exit orifice to enter the hole in the wall ; - a flue pipe guard for positioning over the external end of the flue pipe projecting from the external surface of the wall ; and - a screw-threaded clamping device having respective engagement means at its two ends, to engage the flanged end of the flue pipe at the inner end of the clamping device and the flue pipe guard at the outer end thereof, whereby on installation the clamping device is passed through the flue pipe so that on subsequent tightening thereof the flange of the flue pipe is held to the back-plate of the boiler at the inner end of the clamping device and the flue pipe guard is held to the wall at the outer end of the clamping device.

12. A kit of parts as claimed in claim 11 and substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.