Gas Balanced Flue Guide - Euroheat

Balanced Flue Stove 

Technical Guide 

Document No: IN1105 

© EUROHEAT DISTRIBUTORS (H.B.S) LTD. 1 

Technical Guide IN1105 Ed 5 May 2009

Hearth and Fireplace Requirements 

Do not be tempted to fit the stove into an unsuitable fireplace. Beyond the requirements 

of the building regulations and access to facilitate servicing the stove, providing a 

setting which will complement the stove is not a luxury, it is the practicality of making 

the most of an investment. A good builder will be able to transform even the most 

utilitarian of fireplaces, whether altering its proportions to those of the “Golden Mean” 

ideal, exposing a wooden lintel, stone or simply removing superfluous detailing for 

comparatively small costs, and the result will be a pleasure for many years. 

Minimum clearance 

from combustible 

materials 

Minimum clearance 

from non 

combustible 

materials 

A 12" 300mm** 9" 230mm 

B 6" 150mm** 4" 100mm 

C 1" 25mm** N/A 

D 2" 50mm** 2" 50mm 

E 6" 150mm** 4" 100mm 

F 

F 

E 

A 

12mm of non 

combustable material. 

12mm of non 

combustable material. 

Curtains and furnishings should be a minimum of 

1m from the stove. 

C 

B 

D 

“Golden Mean” 

Side Profile 

1/3 2/3 

“Golden Mean” 

Front View 

The stove can be placed on a combustible 

floor providing it can support the weight, 

and providing a non combustible hearth 

plinth with a minimum thickness of 

12mm is utilized. 

** The measurements provided are 

for guidance only. 

In all installations any surrounding 

flammable materials must not be allowed 

to exceed 80°C or a non combustible 

shield provided in accordance with 

current regulations. The stove must 

always stand perfectly level and have 

sufficient space allowing for service 

work. 


Technical Guide IN1105 Ed 5 May 2009 

1 

2/3 2/3

Balanced Flue Systems 

A balanced flue system utilizes a double concentric pipe, the inner one taking away the products of combustion 

and the outer one bringing the air supply to the stove. This system allows a gas stove to be installed where no 

flue exists, and because the flue needs very little vertical height to operate, it is often possible to route the flue 

through the room wall to the outside. 

With all the air necessary for combustion being supplied through the outer pipe directly from the outside, the 

room in which the stove is installed needs no ventilation specifically for the stove. 

The balanced flue system has been designed to give a huge range of installation options, terminating either 

horizontally or vertically, as illustrated in the diagram below. 

Deciding on which form the balanced flue should take will very much be constrained by the termination of the 

flue. Building Regulations lay out definitive guide lines for where a flue can terminate, see the diagram later in 

this document, and if the building is listed there may be constraints on the position of any terminal and advice 

should be sort from the appropriate regulatory authority. 



No Chimney ----- No Problem 

This document will help you design and your qualified engineer install a suitable balanced flue system for your 

stove. Following the simple guide lines will allow a balanced flued stove to be fitted in most situations where 

a conventionally flued stove could not be fitted. 

Top to Horizontal High Level Flue Kit 

It is not necessary for the stove to be situated against the outside wall through which the 

flue will pass, as the versatility of the balanced flue system can allow for considerable 

lengths of horizontal run of the flue. 

Top to Vertical High Level Flue Kit 

The vertical balanced flue system is ideal in situations such as in a newly constructed 

conservatory where there are no walls through which to pass a horizontal flue. The flue will 

rise from the stove vertically passing through the roof where it will then terminate with a 

vertical terminal. 

Minimum height 2m maximum 30m. 

Rear to Horizontal Low Level 

The low level horizontal kit is probably the simplest method of installation and allows 

you to fit the stove against any suitable outside wall in any room in your property. 

Maximum horizontal length 440mm, minimum length 310mm. 

Existing Chimney Adapter Kit 

The flue kits are also designed to be able to utilize an existing chimney. Properties 

which are designed with a high thermal efficiency may not allow an air brick 

to be fitted to supply air to a stove over 7kW input, the balanced flue stove 

overcomes this requirement as it is a sealed appliance. 

In some cases the top section of a chimney may have been removed and the 

versatility of the balanced flue system allows you to use what remains of the 

chimney using the chimney adapter kit. 



Location of Outlets from Flues Serving Gas Balanced Flue Stoves. 

Minimum Separation Distances for Terminals in mm 

Location Balanced Flue 

A Below an opening Appliance 

rated heat 

input 

B Above an opening (1) 

0-7kw 

>7-14kw 

> 14-32kw 

>32 

0-32kw 

>32kw 

C Horizontally to an opening (1) 0-7kw 

>7-14kw 

>14kw 

D Below gutters, soil pipes or drain 

pipes 

300 

300 

600 

1500 

2000 

300 

600 

300 

400 

600 

E Below eaves 300 

Q Above the highest point of 

F Below balcony or car port roof 

600 

600 

intersection with the roof 

R Flue should not penetrate shaded area 600 

G From a vertical drain pipe or soil 

300 

pipe 

S Flue should not penetrate shaded area 200 

Note (1) 

An opening means an openable element, such as an openable window, or a fixed opening such as an air 

vent. However, in addition, the outlet should not be nearer than 300mm to an opening into the building fabric 

formed for the purpose of accommodating a built in element, such as a window frame. 



 

Minimum Separation Distances for Terminals in mm 

Location Balanced Flue 

H From an internal or external corner 

or to a boundry alongside the 

terminal 

600 

I Above ground,roof or balcony level 300 

J From a surface or a boundary facing the 

terminal 

600 

K From a terminal facing the terminal 600 

L From an opening in the car port into the 

building 

M Vertically from a terminal on the same 

wall 

N Horizontally from a terminal on the 

same wall 

1200 

1200 

300 

P From a structure on the roof 1500

Calculating Flue Aspect Ratios 

The stove operates correctly only with air flow induced by the flue system being within the defined parameters. 

To achieve these, the vertical elements of the flue, which induce flue draught and increase the air supply to the 

stove, must be balanced against the horizontal elements of the flue, which offer resistance to flue draught and 

reduce the air supply to the stove. 

The ratio of vertical to horizontal lengths must be calculated to ensure the correct flue draught will be induced 

by the proposed flue. 

The difference in height between the top of the stove and the bottom of the terminal determines the vertical 

height to be used in the calculation. The flue run may necessitate the vertical elements to be separated by 

several horizontal runs, this is not important, only the total height gain is needed. 

The horizontal length is often more tedious to determine, but again, it is the total length which needs to be 

determined, regardless of their being continuous or in stages. Any 90 degree change of direction within the 

flue will offer resistance to flue draught and each change of direction will offer the same resistance to the flue 

draught as a horizontal run of 1000mm. For every 45 degree change in direction the resistance is that of a 

horizontal run of 500mm. 

BALANCED FLUE ASPECT RATIO DYNAMICS ILLUSTRATED 

6.0 

5.5 

5.0 

4.5 

4.0 

3.5 

3.0 

2.5 

2.0 

1.5 

1.0 

0.5 

0 

.5m vertical = 3.5m horizontal max. 

Depending on 

which direction your 

flue configuration 

will take and the 

model of the stove, 

a flue reduction 

plate (FRP) may 

or may not be 

required. 

See pages 24 & 25 

for details. 

1m vertical = 7m horizontal max. 

For 1m vertical rise a flue may have a maximum horizontal run of 7m. 

For each 90 degree bend introduced the horizontal run must be reduced by 1m. 

For each 45 degree bend introduced the horizontal run must be reduced by 500mm. 

0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0 



Basic Principle of Balanced Flue Ratios Illustrated 

Top to Horizontal High Level 

1.5 

1.0 

0.5 

0 

1.5 

1.0 

0.5 

0 

0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0 

Example 'A' 

For a 1m vertical rise a flue can have a maximum of 7m horizontal length. 

0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 

Example 'B' 

Rear to Horizontal Low Level 

Each additional 90 degree bend creates a draught resistance equal to 1m 

of horizontal length. 

Therefore in example 'B' the introduction of 2 x 90 degree bends, 

in a horizontal plain, reduces the maximum horizontal length by 2m. 

Example 'C' 

Flue spigot 

0 Min 310mm/ Max 440mm 

The rear exit flue may have a maximum horizontal run of 440mm 

from the flue spigot, the minimum length 310mm. 



Example 1: Top to Horizontal High Level Kit 

Using the standard top to horizontal high level flue kit only. 

Standard kit starter 

length T1 

Components used 

Standard kit 90 

degree long bend 

Description Part No. 

Top to 150mm 180mm 

HorizontalHigh 

Level Kit 

MS91102 MS91103 

Sleeve liner MS91065 MS91066 

Terminal 

guard 

FP767 FP767 

Closure bezel MS91033 MS91040 

Ceramic rope or 

Fraxfill sealant to 

prevent draughts 

Closure 

bezel 

 

Minimum 

50mm 

Cavity wall 

The closure 

bezel fits around 

the flue pipe 

covering the 

hole through 

a solid wall 

giving the 

installation 

a clean finish 

both inside and 

outside. 

12mm 

Standard kit 

terminal length T2 

Sleeve kit 

(accessory) 

Terminal guard 

(accessory) 

Solid wall 



Example 2: Top to Horizontal High Level Kit 

Taking the attached diagram as an example we can calculate the flue parameters for a top to horizontal flue 

system. 

Total Height = A 

Total Horizontal = B 

In this example 

A = 2.8 Metres B = 1.75 Metres 

Three x 90 degree bends have been used one of which (C) is the standard supply kit bend. This bend is ignored 

from the calculation as it is presumed it will always be used. The two remaining 90 degree bends increase the 

horizontal length by two metres. 

(one metre extra horizontal length per additional 90 degree bend). 

Total Height A = 2.8 Metres 

Total Horizontal B = 1.0 Metres 

In this example there is sufficient vertical rise for the horizontal run, as shown in the graph on page 6. 


Standard kit 

terminal length 

T2 

Accessory 250mm 

length within wall 

Accessory short 

90 O bend 

Accessory 1metre length 

Wall band 

Accessory short 

90 O bend 

Description Part No. Quantity 

Top to 150mm 180mm 

HorizontalHigh 

Level Kit 

MS91102 MS91103 

1 

1 metre length MS91028 MS91034 1 

500mm length MS91029 MS91035 2 

250mm length MS91030 MS91036 1 

90° short bend MS91031 MS91037 2 

Wall band MS91052 MS91053 1 

B 

B+B= Total Horizontal 

A Total height 

Standard kit 

long 90 O bend 

Accessory 

500mm length 

Standard kit 

starter length 

T1 



A 

B

Example 3: Top to Vertical High Level Kit 

The ratio of vertical to horizontal lengths must be calculated to ensure the correct flue draught will be induced 

by the proposed flue. Taking the ratio diagram as an example we can calculate the flue parameters for a top 

to vertical flue system. 





Two x 90deg bends have been used. The two 90 degree bends increase the horizontal length by two metres. 

(One metre extra horizontal length per additional 90 degree bend). 

Total height A = 3.5 Metres 

Total Horizontal B =0.9 Metres 

In this example there is sufficient vertical rise for the horizontal run, as shown in the illustration on page 6. 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

(accessory) 

 

(accessory) 

 

 



Top to Vertical 

High Level Kit 

150mm 

MS91100 

180mm 

MS91101 

1 


500mm length MS91029 MS91035 3 






This example incorporates two 45 degree bends, a situation commonly encountered when having to route flue 

pipe around an obstacle such as a beam. When calculating the horizontal run the 45 degree bends equate to 

an additional 500mm per bend. 

Taking the ratio diagram as an example we can calculate the flue parameters for a top to vertical flue system. 





2 x 45deg bends have been used. The two 45 degree bends increase the horizontal length by one metre. 

(500mm extra horizontal length per 45 degree bend). 

Total height A = 4.5 Metres 

Total Horizontal B = 2.0 Metres 

In this example there is sufficient vertical rise for the horizontal run, as shown in the illustration on page 6. 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

(accessory) 





150mm 

MS91100 

180mm 

MS91101 

1 


Adjustable 

length 

MS91045 MS91046 1 



Roof flashing MS91063 MS91063 1 




The minimum vertical height for a top to vertical flue is two meters of flue and the top to vertical kit 

components. 





150mm 

MS91100 

180mm 

MS91101 

1 



Roof flashing MS91063 MS91063 1 

 

 

 

 

 

 

 

 

 

 

(accessory) 

 

 



Example 6: Through Ceilings and Roof Spaces 

Fitting a Top to Vertical High Level Flue Kit Through Ceilings and Roof Spaces 

When installing balanced flue pipe through a ceiling the use of a ceiling support and fire stop spacer are 

recommended. There should be no flue joints at any point as the flue passes through a ceiling. 

There should a minimum clearance of 25mm from the flue pipe to any combustible material. 

No flue joints 

between fire 

stop spacer 

and ceiling 

support. 


Weight of flue 

supported here. 

Ceiling support 

Fire stop spacer 

Weight of flue 

supported here. 

Description 150mm 180mm 

Ceiling support MS91056 MS91057 

Fire stop spacer MS91058 MS91059 

Roof flashing MS91063 MS91063 

Wall band MS91052 MS91053 

Roof flashing 

(accessory) 

 



Example 7: Existing Chimney Adapter Kit Vertical Termination 

Fitting an Existing Chimney Adapter Kit in Conjunction with a High Level Vertical Kit 

There are great advantages in converting an existing chimney into a balanced flue. The existing chimney 

adapter kit can convert either ceramic lined chimneys or an unlined chimney into a balanced flue system. By 

using this system combustion air is drawn from the outside rather than from the property greatly increasing 

overall efficiency. 

In addittion many houses chimney stacks have been removed and the 

roof tiled over. They are usually capped off at attic floor level. 

We have developed a kit which can bring these chimneys back to life 

using a gas balanced flue stove. 

It can also be used in modern properties which have heat 

replacement systems where normal ventilation requirements 

cannot be applied. 

The system requires the use of two flexible flue liners, one to run 

inside the other mimicking the standard balanced flue pipe. 

The inside pipe is for the evacuation of the products of 

combustion and the outer is the air supply for combustion. 

It is imperative that all the joints are sealed 

to make them air tight. 

There follows two examples of the system, 

one is showing an existing chimney breast 

and the system terminating in a 

vertical position (through the roof). 

The second is showing the 

system terminating in a horizontal 

position (through a gable end of 

a property perhaps). 

Using two sizes of flue liner to 

mimic the balanced flue pipe. 

Ensure the seal is tight 

to the adapter kit 

Flue system 

size 

Inner liner Outer liner 

150mm 101mm / 4” 153mm / 6” 

180mm 125mm / 5“ 178mm / 7” 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Existing chimney 

top adapter 

Existing chimney 

bottom adapter 

Depending on which direction your flue configuration will take and the model of the stove, a reduction plate 

may or may not be required. See pages 24 & 25 for details. 



Example 8: Existing Chimney Adapter Kit Horizontal Termination 

Fitting an Existing Chimney Adapter Kit in Conjunction with a Top to Horizontal Kit 

If this orientation is to be used then the standard 90 degree long bend from the top to horizontal kit MUST be 

used so that the last union before the terminal length T2 is a female (F) end. 

Existing chimney top adapter 

Existing chimney bottom adapter 

Flue system 

size 

Inner liner Outer liner 

150mm 101mm / 4” 153mm / 6” 

180mm 125mm / 5“ 178mm / 7” 

Existing chimney top adapter 

350mm 

95mm 

75mm 

100mm 

Accessory 1 

metre length 

Standard kit 

90° long bend 

Standard kit 

starter length 

T1 

Clay 

liner 

Flexible 

liner 

Standard kit 

terminal length 

T2 

Existing chimney bottom adapter 

350mm 

75mm 

The example above is showing an existing chimney adapter kit utilizing a existing clay liner, using a flexible 

liner to run inside the clay liner in order to expel the products of combustion but using the clay liner for the 

feed of combustion air. Ensure that the seals between flexible liner and the adapter are sound and the seal 

between the clay liner and the adapter are also sound. 

It can go through the long 90° bend (in the top to horizontal kit) and terminate through the gable end of the 

property. 



M 

F 

T1 

M 

F 

T2

Example 9: Through a Combustible Roof 

Installation of Top to Vertical High Level Balanced Flue Pipe Through a Combustible Roof 

A 25mm gap of non combustible material must be used when you are passing the balanced flue pipe through 

any combustible material. 

Conservatories can “come alive” with the installation of a stove, but care should be taken when installing a 

stove into a conservatory because the modern ones can be made entirely from plastic (or PVC). Advise from 

your conservatory installer/manufacturer should be sought. 

The flue system should be supported. 

600mm 

600mm 

600mm 



Frequently Asked Questions 

Q. Can the stove be flued directly off the back? 

A. Yes, using the standard low level horizontal kit. 

Q. Can I use a bend directly off the top of the stove? 

A. No, the stove adapter is only designed to fit the telescopic starter length and straight lengths, bends will not 

seal to the flue outlet. 

Q. Can I fit the stove in the corner of a room? 

A. Yes, there is no problem in doing this using the top to horizontal flue kit, but it must be remembered that if 

the corner is also the corner of the property that the termination must be 600mm from any corner. See diagram 

page 5. 

Q. Can the vertical flue be passed through a combustible roof, such as a polycarbonate roof in a conservatory? 

A. Yes, as long as allowances are made for the type of roofing material and suitable insulation is provided. See 

the section on flueing through a combustible roof. 

Q. Can the stove be fitted into a bedroom? 

A. Yes, the stoves are room sealed and below 14kW input. 

Q. Can I cut the lengths of flue pipe? 

A. Yes, however the differential between the inner and outer length has to be maintained. It would be preferable 

to use an adjustable length 

Q. Does the flue terminal need to be guarded? 

A. If the flue terminal is to be sited less than two meters above level ground, 

a balcony or a flat roof where people have access, a guard must be fitted. Local 

by-laws may also require a further minimum height where the terminal is sited 

adjoining a public footpath. 

Q. If I have a high level horizontal kit can I then terminate it vertically? 

A. Yes, there is a vertical terminal with a crimped end which will fit to the 

flue system. 

Q. Do I need an air brick or other ventilation for supplying free air to the 

stove? 

A. No, the stove is room sealed and does not have any requirement for free 

air. 

Q. Does it matter how far out of the wall the terminal is fitted on a horizontal flue kit? 

A. Yes, there should be 12mm of flue pipe visible before the start of the flue terminal. Any greater length can 

upset the balanced flues operation. 

Q. What colours are the flue pipe available in? 

A. The flue pipe is supplied in one colour, a matt grey finish, which closely matches the cast finished stoves and 

complements the enamel finished stove. It is possible to change the colour using heat resistant paint. 

Q. To what wind speed are the terminals tested to? 

A. The maximum wind used is 12.5 m/s with 10% error. (28mph). 

Vertical terminal with 

crimped end 

Size Part No: 

150mm MS91047 

180MM MS91048 

Q. What is the maximum length the flue can travel horizontaly from the rear outlet of the stove? 

A. The standard low level horizontal flue kit gives a maximum extension of 440mm. No additional lengths or 

bends should be fitted. 



Components of Top to Horizontal High Level Kit 

150mm kit MS91102 

180mm kit MS91103 

This is a high level horizontal flue kit. Other sections may be added to achieve the desired termination. For 

additional lengths and accessories see pages 21 to 23. 

 

Telescopic terminal length 

(T2) 

 

 

 

 

 

T2 

 

 

 

 

 

 

Clamp band 

Telescopic starter length (T1) 

which must be used as the 

first length of flue pipe from 

the stoves flue collar 

Dimensions of standard 150mm flue kit 

90° Long bend 



T1 

T1 

Dimensions of standard 180mm flue kit 

Max: 555mm 

Min: 470mm 

The min can be reduced further by cutting 40mm 

off the T2 section 

T2 

12mm 

Max 555mm 

Min 445mm 

The min can be reduced 

further by cutting 40mm 

off the T1 section

Components of Top to Vertical High Level Kit 

150mm kit MS91100 

180mm kit MS91101 

This kit is used when the installation requires the termination to be through a roof. Further components will 

be required with this kit. For additional lengths and accessories see pages 21 to 24. 

200mm 

250mm 

T1 

Adjustable Starter Pipe 

Toatal length Minimum Length 

for Calculations 

Vertical Terminal 

Locking Band 

Adjustable Starter Pipe 

Maximum Length 

For Calculations 

250mm 30mm 170mm 



Components of Rear to Horizontal Low Level Kit 

150mm kit MS91097 

180mm kit MS91098 

Only the standard kit may be used, additional bends and lengths MUST not be used as they will adversely 

effect the performance of the balanced flue and could be dangerous. 

Telescopic Module 

(horizontal adjustable) 

T1 

Maximum 

Length 440 mm 

Minimum 

Length 310 mm 

Spacers and self tapping 

screws for wind shield 

Horizontal 

Terminal 

Terminal Guard 

Wind shield 



Additional Flue Pipe System Accessories 

Each section of additional flue pipe is 

supplied with a locking band. 

1 metre pipe 

500mm pipe 

250mm pipe 

90 degree short bend 

45 degree short bend 

Adjustable length 250mm 

Wall Band 

When calculating the amount of flue pipe required the usable length and not the overall length should be 

used, see the table below. 

Description 150mm 180mm Over all length Useable length 

1 metre pipe MS91028 MS91034 1m 960mm 

500mm pipe MS91029 MS91035 500mm 460mm 

250mm pipe MS91030 MS91036 250mm 210mm 

90 Degree bend MS91031 120mm vertical 170mm horizontal 

90 Degree bend MS91037 246mm vertical 186mm horizontal 

Adjustable pipe MS91045 MS91046 195 max length 85 min length 

45 Degree bend MS91054 MS91055 170mm vertical 75mm horizontal 

2 x 45 Degree bend 

off set 

MS91054 x 2 MS91055 x 2 340mm 150mm off set 

Wall band MS91052 MS91053 



Additional Flue System Accessories 

Ceiling Support & Fire Stop Spacers 

Required when a balanced flue kit passes through a ceiling. 

Fire Stop 

Description Part No. 150mm Part No. 180mm 

Ceiling Support MS91056 MS91057 

Fire Stop MS91058 MS91059 

Existing Chimney Adapter Kit 

Allows an existing sound chimney to be used as part of the balanced flue. 


Existing Chimney Adapter Kit MS91085 MS91086 

Sleeve Liner 

Required when flue pipe passes through a cavity wall. It can be cut down to size or an extender sleeve added. 

Max 360mm 

Min 240mm 

Outer diameter 

150mm kit 165mm 

180mm kit 195mm 

Extender sleeve 

Ceiling Support 


Sleeve Liner MS91065 MS91066 

Extender sleeve MS91067 MS91068 



Cavity

Additional Flue System Accessories 

Roof Flashing 

Required when a balanced flue kit passes through the surface of a roof, 

flat or pitched. 

Roof Flashing 

Description Part No. 150mm kits Part No. 180mm kits 

Roof Flashing MS91063 MS91063 

Terminal Guard 

The terminal guard is suitable for High-Level Top to Horizontal kits only. The flue outlet should be protected 

with a guard if persons could come into contact with it or if it could become damaged. If a flue outlet is in a 

vunerable position, such as where the flue discharges within reach of the ground (less than 2m), or a balcony, 

veranda or an opening window. 

Terminal Guard Closure Bezel 

Closure Bezel 

The closure bezel fits around the flue pipe covering the hole through the wall and gives the installation a clean 

finish. 


Closure Bezel MS91033 MS91040 

Terminal Guard FP767 FP767 

Fraxfill 

Fraxfill is a pliable (tacky putty) 

white ceramic fibre gap fill supplied 

in a 300g cartridge for use with a 

sealant gun. Fraxfill is recommended 

for applications with operating 

temperatures of up to 1200°C. 

 


Fraxfill MS9045 MS9045 



Flue Reduction Plate (FRP) 

Before Installation 

Depending on which direction your flue configuration will take, a reduction plate may or may not be 

required. 

The choke plate is a circular plate which fits under the inner flue connection. 

The list below will advise which FRP will or will not be needed. 

Harmony 15 Stanford 15 (H15 & S15) 

Description Fuel Type FRP 

Top to horizontal high level kit with 

standard flue kit 

Top to vertical high level kit 

Rear to horizontal low level kit 

Natural 

Gas 

58mm 

LPG 58mm 

Natural 


40mm 

LPG 45mm 

Natural 


No FRP 

LPG No FRP 

Harmony 25 Stanford 25 (H25 & S25) 






Natural 


66mm 

LPG 66mm 

Natural 


50mm 

LPG 50mm 

Natural 


No FRP 

LPG No FRP 



Top flue connection for top to horizontal 

high level kit and top to vertical kit 

Harmony 35 (H35) 






Natural 


76mm 

LPG No FRP 

Natural 


55mm 

LPG 55mm 

Natural 


No FRP 

LPG No FRP 

Harmony 45 (H45) 






Natural 


70mm 

LPG 70mm 

Natural 


70mm 

LPG 70mm 

Natural 


No FRP 

LPG No FRP 

Rear flue connection for rear to 

horizontal low level kit 



Stove Technical Data 

Harmony 15 

150mm Flue kit system 

and accessories 

Harmony 25 



Harmony 35 



Harmony 45 



Stanford 15 



Stanford 25 



 

 

 

 

435 

455 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

240 

 

150 ID 

 

 

 

160 

270 

120 

150ID 

150mm Flue kit Part No. 

Top to horizontal 

high level kit 

MS91102 

Top to vertical high 

level kit 

MS91100 

Rear to horizontal 

low level kit 

MS91097 




MS91103 


level kit 

MS91101 


low level kit 

MS91098 



495 

600 

565 

 

 

 

670 

682 

 

750 




MS91102 


level kit 

MS91100 


low level kit 

MS91097 




MS91103 


level kit 

MS91101 


low level kit 

MS91098 




MS91102 


level kit 

MS91100 


low level kit 

MS91097 




MS91102 


level kit 

MS91100 


low level kit 

MS91097

Fitting High Level Horizontal Flue Kit 

The flue system starter length should be sealed to the stove’s flue spigot with a heat proof sealant, (we 

suggest “fraxfill”, part number MS9045). Apply a bead of heat resistant sealant to the inner face of the outer 

flue spigot and the outer face of the inner flue pipe. The clamp should be used to secure the first elbow or 

additional length and the appropriate heat proof tape used to secure the telescopic fitting. 

Heat proof 

sealant 

Heat proof 

sealant 

 

Where the flue passes through 

a cavity wall, the hole must be 

sleeved for its entire length. 

Accessory 90° 

short bend 

 

 

 

Standard kit 


 

 

Wall band 

The guide giving the permitted flue configurations must 

be consulted to verify that a proposed flue is possible. The 

“long 90° bend” supplied as standard with the stove must be 

incorporated into the system to ensure a non crimped end at 

the last fitting before the termination length T2. 

All joints between the fixed lengths of flue must 

be secured with locking bands, and every meter in 

length horizontally or vertically must be supported. 

It is your responsibility to ensure that no part of the 

flue installation contravenes any gas or building 

regulations. 

 



 

 

 

Standard kit 



short bend 

Locking band

Position of Flue Terminal on Outside Wall 

The position of the terminal on the outside wall should be 12mm from 

the edge of the terminal mesh to the face of the outside wall. 

If it protrudes further than 12mm it may be adversely affected by wind 

blowing across the terminal so upsetting the balanced flue operation. 

If it is fitted with less than 12mm clearance then the vented exhaust 

gases may be drawn back into the balanced flue primary air inlet so 

adversely effecting the operation of the balanced flue. 

The flue pipe passing through the wall should be angled slightly 

downwards (1 degree) towards the terminal so as to stop rain water 

entering and passing along the flue. 

Horizontal Flue Passing Through a Combustible or Cavity Wall 



prevent draughts 

25mm air gap 

incorporated as part 

of the Flue System 

Sleeve liner 

T1 

50mm 

minimum 

12mm 



T2 

1° incline 

Seal the bezel part of sleeve liner 

to the outer face of the wall using 

a suitable sealant 

Sleeve liner 

12mm 



prevent draughts

Fitting the High Level Vertical Flue Kit 

The flue system starter length should be sealed to the stove’s flue spigot with a heat proof sealant,(we suggest 

“fraxfill”, part number MS9045). Apply a bead of heat resistant sealant to the inner face of the outer flue spigot 

and the outer face of the inner flue pipe. The clamp should be used to secure the first elbow or additional 

length and the appropriate heat proof tape used to secure the telescopic fitting. 

Heat proof 

sealant 

Wall bands should be fitted 

to support the flue pipe. 

The telescopic starter length 

must be used so that the 

male end of the flue pipe 

connects to the vertical flue 

terminal. 


short bend 

The vertical terminal will only fit 

the male end of the flue pipe. 

 

 

 



 

Heat proof 

sealant 


short bend 

 

 

 

All joints between the fixed lengths of flue 

must be secured with locking bands, and 

every meter in length horizontally or vertically 

must be supported. It is your responsibility to 

ensure that no part of the flue installation 

contravenes any gas or building regulations.

Fitting the Low Level Horizontal Flue Kit 

The horizontal flue kit starter length should be secured by means of a self tapping screw. If it is to pass through 

a cavity wall then a sleeve liner (150mm part No. MS91065. 180mm part No. MS91066) should be fitted. 

The terminal section should be fitted with the snorkel pointing upwards and the wind shield to protect the 

terminal outlet. Only the standard kit may be used from the rear flue outlet. 

Secure starter length with 

a self tapping screw 

Flue should be sleeved if passing 

through a cavity wall 

Apply a bead of heat resistant sealant (we 

suggest “fraxfill”, part number MS9045) to the 

inner face of the outer flue spigot and the outer 

face of the inner flue pipe. 

Wind Shield 

The wind shield should be fitted using the spacers so that it baffles 

the top holes in the horizontal terminal to protect it from the 

effects of the wind. The top holes are pre-drilled into the terminal 

however in some cases the lower holes may need to be drilled to 

complete the installation. 

Terminal snorkle 

Sleeve kit 

150mm part No. MS91065 

180mm part No. MS91066 

The terminal length should be 

fitted with the snorkle pointing 

upwards. 

Fitting of Flue Spigot to Rear of the Stove 

Remove the inner and outer spigot from the top of the stove. Remove the rear blanking plate and fit the inner 

and outer spigots and the flue reduction plate (FRP) if required, see pages 23 and 24, to the rear of the stove. 

Fit the blanking plate onto the top plate. 



Glossary of Terms 

Term Description 

Top to horizontal high level 

The flue kit rises from the top of the stove, it includes a long sweeping 90° 

bend and terminates through the side wall of a property. 

Top to vertical high level 

The flue kit rises from the top of the stove and terminates vertically through 

a roof. 

Low level horizontal 

The flue runs horizontally from the back of the stove and terminates through 

the side wall of a property. 

T1 

Telescopic starter length. The first section of the flue kit which can telescope 

into the section of flue to follow it. Top connection only. 

T2 

Telescopic terminal length. The last section of the top to horizontal flue kit 

which can telescope into the section of flue before it. 

FRP 

Flue reduction plate. A choke plate fitted into the outlet of the stove to 

reduce the velocity of the flue gases. 

Sleeve liner 

Telescopic sleeve, required when a flue passes through a combustible or 

cavity wall. 

Outlet 

Position of the flue terminal, which is governed by Building Regulations, see 

diagram on page 6. 

Terminal Fitted to the end of the flue system, supplied with the flue kits. 

Wall band Required to support every 1m in length vertically or horizontally of flue. 

Locking band 

Supplied in the kits and with every additional length of flue pipe to secure 

the joints between sections. 

Closure bezel 

The closure bezel fits around the flue pipe covering the hole through the 

wall and giving the installation a clean finish. 

A wire mesh guard required when the outlet is in a vulnerable position, 

Terminal guard such as where the flue discharges within reach of the ground (less than 

2m), or a balcony, verandah or a opening window. 

Required when a vertical flue passes through a roof. A vulcanised rubber 

Roof flashing gaiter through which the flue pipe passes allowing a water tight seal to be 

made. 

A metal plate with locking band required when a flue passes through a 

Ceiling support ceiling. Fitting onto the floor above the ceiling through which it passes with 

a clamp to secure it to the flue pipe and support the weight of the flue. 

Fire stop spacer 

A metal plate which fits on the ceiling through which the stove passes which 

is required to conform to Building Regulations. 

The existing chimney adapter kit can convert either ceramic lined chimneys 

Existing chimney adapter kit 

or an unlined chimney into a balanced flue system. By using this system 

combustion air is drawn from the outside rather than from within the 

property. 

Terminal snorkle 

The upturned inner pipe within the low level horizontal flue kit, that when 

fitted should be pointing upwards. 

This fits on the outside of the low level horizontal terminal, standing away 

Wind guard from the body of the terminal guard, with spacers, so protecting the top 

holes of the terminal from the effects of wind blowing directly on them. 

Fraxfill is a pliable (tacky putty) white ceramic fibre gap fill supplied in 

Fraxfill (MS9045) a 300g cartridge for use with a sealant gun. Fraxfill is recommended for 

applications with operating temperatures of up to 1200°C. 



When installing the stove this documnet should be used in 

conjunction with Euroheats Installation Instructions specific to the 

stove supplied. 

The gas stoves in the Euroheat range may only be installed by a 

suitably qualified Gas Safe technician using the appropriate fittings 

for the gas type being installed, and the stove must not be modified 

in anyway. 

Important 

The installer is responsible under the Health and Safety at Work Act 1974 vi the caustic nature of fire cement 

and the possibility of disturbing asbestos and other materials such as ceramic in existing installations and 

to suggest appropriate protection to be given to the person (s) carrying out the installation. The complete 

installation must be carried out with due reference to the British Standards, Codes of Practice and Building 

Regulations relevant to the fuel type being installed, and the manufacturers installation instructions. 

This document is a General Installation Guide only. It does not replace the installation instructions or building 

regulations. No installation should be undertaken unless the installer is suitably qualified. 

Information from the Euroheat Technical Team 

Euroheat and Nestor Martin have a policy of continual research and development and reserve the right to 

modify its appliances without prior notice. 

We make every effort to ensure that the information provided in this document is correct and accurate at 

the time of printing. Continued updates occur to adapt documents to customer requirements and appliance 

changes. For the latest editions of all Euroheat documentation visit our web site 

www.euroheat.co.uk. 

We would request that you inform Euroheat of information which you feel is not provided in this document 

which would assist other users in the future. 

The Euroheat Technical Team 

www.euroheat.co.uk 

Euroheat Distributors (H.B.S.). Ltd., 

Unit 2, Court Farm Business Park, 

Bishops Frome, Reception: 01885 491100 

Worcestershire, Technical Support: 01885 491117 

WR6 5AYY. Email: tech@euroheat.co.uk

Gas Balanced Flue Guide - Euroheat

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