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Open Wood Fireplace A Series Timber Installation Guide

Open Wood Fireplace A Series Timber Installation Guide PDF »


The Heatmaster open fireplace system comes as a fully self-contained fireplace kit. The firebox, log grate, ashtray, flues and cowl are the basic components (Fig 1A). When installing your Heatmaster fire place please be sure to read the following carefully and to comply with all clearances. Full specifications are available upon request.

Fig 1A – Flue System sizes and Specifications

Model No A450 A650 A750 A900
Inner Flue 150mm 180mm 200mm 200mm
Outer Flue 200mm 230mm 250mm 250mm

Fig 1A – Dimensions

Model No A B C D E F G H I J
A450 595mm 395mm 670mm 195mm 205mm 195mm 90mm 100mm 195mm 200mm
A650 840mm 470mm 680mm 315mm 205mm 315mm 155mm 110mm 255mm 215mm
A750 910mm 495mm 680mm 325mm 260mm 325mm 140mm 90mm 270mm 225mm
A900 1060mm 565mm 740mm 400mm 260mm 400mm 180mm 125mm 315mm 250mm


Fig 1B – Min. Framing Dimensions on Non-combustible floor

Model No A450 A650 A750 A900
Height from non combustible floor 770mm 780mm 780mm 840mm
Width 645mm 890mm 960mm 1110mm
Depth “C” 430mm 505mm 530mm 600mm

Fig 1B – Min. Framing Dimensions using standard hearth (fig 2A) on combustible floor

Model No A450 A650 A750 A900
Height from non combustible floor 808mm 818mm 818mm 878mm
Width 645mm 890mm 960mm 1110mm
Depth “C” 430mm 505mm 530mm 600mm


Hearth details

Hearth details for combustible flooring.

The hearth required under the Heatmaster firebox consists of two sheets of 6mm thick fibre-cement with a 1mm thick sheet of steel between them. It must be spaced off the floor with non-combustible spaces (square tubing) to give a 25mm ventilated air gap (Fig 2A). It should extend 350mm in front, 25mm behind and 200mm either side of the firebox opening. (Fig 2B)

Fig 2A – Hearth Installation


Fig 2B – Hearth Installation

Model No width ‘A’ depth ‘B’
A450 995mm 770mm
A650 1240mm 845mm
A750 1310mm 870mm
A900 1460mm 940mm


Fig 2C – Installing your Heatmaster step by step

Timber Installation. Fully insulated Models. A step by step guide to installing “A series” Heatmaster.

Step one.
After selecting your Heatmaster unit and installing your hearth (see above diagram fig 2A) erect framework with the appropriate clearance (see timber framing specificationfig 1B).

Step two.
Install selected insulated “A series” Heatmaster unit along with flues (see Flue detail diagram fig 3A).

Step three.
Enclose framing with plasterboard/gyprock or timber paneling, ensuring approved clearances are maintained.

Step four.
Select one of our many finishing options. A wide range of stone, marble, cast iron or steel fascias and mantelpieces are available.

Fig 2D – Finishing your Heatmaster intallation


Flue details

Fluing your Heatmaster fireplace.

The Heatmaster double skin flue kit, into timber and plaster must have clearance of 25mm from any combustible material. Be sure the inner stainless steel flue crimped end faces down while the outer galvanized flue crimped end faces up. The first length of galvanized flue must have ventilation holes at the bottom; these cool the flue down by allowing air to travel in between the two skins. Be sure to pop rivet (or use self-tapers) each stainless and galvanized flue length together along with the cowl. The flue must protrude above the roofline by no less then 600mm with nothing obstructing within 3600mm (See diagram 3B).

Fig 3A – Flue installation


Fig 3B – Flue Roof Clearance


Fig 3C – Off sets and Clearances