Baxi 35/80 IE Release note

Installation & Servicing Instructions
Baxi System
35/80 IE & 60/100 IE
Gas Fired Wall Mounted System Boiler
Please keep these instructions safe.
Should you move house, please hand
them over to the next occupier.
Page 1
Natural Gas

Baxi System 35/80 IE
Baxi System 60/100 IE
Baxi is one of the leading manufacturers of domestic heating products in the UK.
Our first priority is to give a high quality service to our customers. Quality is designed into
every Baxi product - products which fulfil the demands and needs of customers, offering
choice, efficiency and reliability.
To keep ahead of changing trends, we have made a commitment to develop new ideas using
the latest technology - with the aim of continuing to make the products that customers want to
buy.
Everyone who works at Baxi has a commitment to quality because we know that satisfied
customers mean continued success.
We hope you get a satisfactory service from Baxi. If not, please let us know.
The boiler meets the requirements of Statutory Instrument " The Boiler (Efficiency)
Regulations 1993 No 3083" and is deemed to meet the requirements of Directive 92/42/EEC
on the energy efficiency requirements for new hot water boilers fired with liquid or gaseous
fuels:-
Type test for purpose of Regulation 5 certified by: Notified Body 0051.
Product/Production certified by: Notified Body 0051.
For IE only.
Baxi is a BS-EN ISO 9001
Accredited Company
Page 2
Contents

Section Page
1.0 Introduction 4
2.0 General Layout 5
3.0 Appliance Operation 6
4.0 Technical Data 7
5.0 Dimensions and Fixings 9
6.0 System Details 10
7.0 Site Requirements 12
8.0 Installation 17
9.0 Commissioning the Boiler 26
10.0 Completion 28
11.0 Servicing the Boiler 29
12.0 Changing Components 31
13.0 Illustrated Wiring Diagram 39
14.0 Fault Finding 40
15.0 Short Parts List 43
Page 3
1.0 Introduction

Baxi declare that no substances harmful to health are contained in the appliance or
used during appliance manufacture.
1.1 Description
1. The Baxi System 35/80 IE and 60/100 IE are fully automatic gas fired wall mounted system
boilers. They are room sealed and fan assisted.
2. The boilers are set to give a maximum output of 24.0kW (35/80 IE) or 29.3kW (60/100 IE).
3. They are designed for use on Natural Gas (G20) and can be converted to use Propane
(35/80 IE & 60/100 IE) or Butane (35/80 IE).
4. The boiler incorporates a circulating pump and expansion vessel. It is suitable for use only
on fully pumped sealed systems.
5. The boiler data badge gives details of the model and serial number and is situated on the
control box. It is visible when the case front panel is removed (Fig. 1).
Fig. 1
NOTE: This appliance must be installed in accordance with the manufacturer's
instructions and the regulations in force. Read the instructions fully before installing
or using the appliance.
6. The boiler is intended to be installed in residential / commercial / light industrial E.M.C.
environments on a governed meter supply only.
7. The boiler must be installed with one of the purpose designed flues such as the standard
horizontal flue kit, part no. 247719.
8. All systems must be thoroughly flushed and treated with inhibitor (see section 6.1).
1.2 Installation

The installation must be carried out by a Competent Person and installed in accordance with
the current edition of I.S. 813 "Domestic Gas Installations", the current Building Regulations
and reference should be made to the current ETCI Rules for Electrical Installation.
1.3 Optional Extras
Various flue extensions, bends, vertical flue kits,control accessories etc. are available as
optional extras. These are detailed in a separate publication.
Page 4
2.0 General Layout

2.1 Layout
1. Air Pressure Switch
2. Expansion Vessel
3. Burner Manifold
4. Automatic Air Vent
5. Circulation Pump
6. Drain Off Point
7. Pressure Relief Valve
8. DHW Relay PCB
9. System Pressure Gauge
10. PCB
11. Control Box
12. Flame Sensing Electrode
13. Spark Electrode
14. Burner
15. Primary Heat Exchanger
16. Fan Assembly
17. On/Off/Reset Selector Switch
18. Central Heating Temperature Control
19. Flame Failure
20. Safety Thermostat
21. Fault on Fan or Flue
22. Fault on Pump or Low System Pressure
23. Temperature Indication Only
24. Fault on Central Heating Sensor
25. Power On
26. Hot Water Mode
27. Central Heating Mode
28. Burner On
When neons 19 to 24 are constantly illuminated, they indicate the temperature of the central
heating water.
Page 5

3.0 Appliance Operation
Boiler Primary Circuit
3.1 Operating Mode (Fig. 2)
Fig. 2
Key
1 Heat Exchanger
2 Burner
3 Ignition Electrode
4 Flame Sensing Electrode
5 Gas Valve
6 Pump
7 Automatic Air Vent
8 Pressure Relief Valve
9 Boiler Drain Point
10 Gas Inlet

11 Boiler Flow
12 Boiler Return
13 Pressure Gauge
14 Automatic By-Pass
15 Hydraulic Differential Pressure Sensor
16 Safety Thermostat
17 Central Heating Temperature Sensor
18 Expansion Vessel
19 Water Heating Sensor
1. With a demand for heating, the pump circulates water through the primary circuit. At a pre-
determined flow rate the hydraulic differential pressure switch operates, initiating the ignition
sequence.
2. The main burner ignites at low rate, then the gas valve controls the gas rate to maintain the
heating temperature measured by the temperature sensor.
3. When the flow temperature exceeds the setting temperature, a 3 minute delay occurs
before the burner relights automatically (anti-cycling). The pump continues to run during this
period.
4. When the demand is satisfied the burner is extinguished and the pump continues to run for
a period of 3 minutes (Pump Overrun).
IMPORTANT: When the selector switch is in the '0' (Off) position the electrical
supply to the boiler is isolated. The boiler will not operate.
3.2 Frost Protection Mode
1. The frost protection mode is integral to the appliance and functions only with the selector
switch (see Section 2.1) in the domestic hot water and central heating position. If the system
temperature falls below 5°C then the boiler will fire on its minimum setting until a flow
temperature of 30°C is reached. This will only protect the boiler, not the complete system.
Further protection can be incorporated by using a system frost thermostat.
3.3 Pump Protection
1. With the selector switch (see Section 2.1) in either the central heating or central heating
and hot water position the pump will automatically operate for 1 minute in every 24 hours to
prevent sticking.
Page 6
4.0 Technical Data
4.1 System 35/80 IE
Appliance Type C12 C
32
Appliance Category CATⅡ 2H 3+
Heat Input (Gross)
Max Min

kW 26.3 10.6
Btu/h 89,739 36,170
Heat Output Max Min
kW 24.0 9.3
Btu/h 81,891 31,740
Max Gas Rate (Natural Gas - G20)
(After 10
Mins)
m3/h 2.75
ft3/h 98.12
Burner Pressure (Natural Gas - G20)
Max Rate Min Rate
mbar 12.2 ±0.5 2.5 ±0.5
in wg 4.88 ±0.2 1.0 ±0.2
Inlet Pressure (Natural Gas - G20)
mbar 20
in wg 8
Burner Injector (Natural Gas - G20)
12 x 1.28mm Diameter
Electrical Supply 230V~ 50Hz
(Appliance must be connected to an earthed supply)
Power Consumption 170W
External Fuse
Rating 3A Maximum
Internal Fuse Rating
Fuse 2A Fast Blow to BS 4265
Electrical Protection
IPX5D
NOx
Class 3
Flue Terminal Diameter 100mm
Dimensions Projection 95mm
Connections copper tails
Gas Supply - 3/4"
Central Heating Flow - 3/4"
Central Heating
- 3/4"

Return
Pressure Relief
Discharge - 1/2"
Outercase Dimensions
Casing Height - 780mm
Overall Height Inc
Flue Elbow - 980mm
Casing Width - 450mm
Casing Depth - 345mm
Clearances
Both Sides 5 mm Min
Above Casing 200 mm Min
Below Casing 200 mm Min
Front 450 mm Min (For Servicing)
Front 5 mm Min (In Operation)
Weights kg
Packaged Boiler
Carton 45
Packaged Flue Kit 3
Installation Lift
Weight 37
Central Heating Primary Circuit Pressures
bar
Safety Discharge 3
Max Operating 2.5
Min Operating 0.2
Recommend Operating 1-2
Pump - Grundfos UP 15-60
Available Head See graph below
Expansion Vessel - (Integral with appliance)
bar
Min Pre-charge
Pressure 0.5
litre
Max Capacity of
CH System 125
Primary Water
1.0

Content of Boiler
(unpressurised)
Temperatures
C.H. Flow Temp (adjustable)
35°C to 85°C max (±5°C)
LPG Gases Propane - G31 and Butane - G30
Burner Injector 12 x 0.65mm diameter
Burner Pressure Max Rate Min Rate
Propane mbar 36.2 ±0.5 10.8 ±0.5
in wg 14.5 ±0.2 4.3 ±0.2
Butane mbar 28.8 ±0.5 7.7 ±0.5
in wg 11.5 ±0.2 3.1 ±0.2
Inlet Pressures Propane Butane
mbar 37 28/30
in wg 14.8 11.2
SEDBUK Declaration For System Boiler 35/80 IE
The seasonal efficiency (SEDBUK) is 78.6 %
This value is used in the UK Government's Standard Assessment Procedure (SAP) for
energy rating of dwellings. The test data from which it has been calculated have been certified
by 0051.
Page 7
Appliance Type C12 C
32
Appliance Category CATⅡ 2H 3P
Heat Input (Gross)
Max Min

kW 32.6 11.9
Btu/h 111,250 40,610
Heat Output Max Min
kW 29.4 10.4
Btu/h 100,330 35,490
Max Gas Rate (Natural Gas - G20)
(After 10 Mins)
m3/h 3.45
ft3/h 122
Burner Pressure (Natural Gas - G20)
Max Rate Min Rate
mbar 12.5 ±0.5 1.8 ±0.5
in wg 5.0 ±0.2 0.7 ±0.2
Inlet Pressure (Natural Gas - G20)
mbar 20
in wg 8
Burner Injector (Natural Gas - G20)
15 x 1.28mm Diameter
Electrical Supply 230V~ 50Hz
(Appliance must be connected
to an earthed supply)
Power Consumption 190W
External Fuse
Rating 3A Maximum
Internal Fuse Rating
Fuse 2A Fast Blow to BS 4265
Electrical Protection
IPX5D
NOx
Class 3
Flue Terminal Diameter 100mm
Dimensions Projection 95mm
Connections copper tails
Gas Supply - 3/4"
Central Heating Flow - 3/4"
Central Heating
- 3/4"

Return
Pressure Relief
Discharge - 1/2"
Outercase Dimensions
Casing Height - 780mm
Overall Height Inc
Flue Elbow - 980mm
Casing Width - 450mm
Casing Depth - 345mm
Clearances
Both Sides 5 mm Min
Above Casing 200 mm Min
Below Casing 200 mm Min
Front 450 mm Min (For Servicing)
Front 5 mm Min (In Operation)
Weights kg
Packaged Boiler
Carton 47
Packaged Flue Kit 3
Installation Lift
Weight 39
Central Heating Primary Circuit Pressures
bar
Safety Discharge 3
Max Operating 2.5
Min Operating 0.2
Recommend Operating 1-2
Pump - Grundfos UP 15-60
Available Head See graph below
Expansion Vessel - (For Central Heating only. Integral with appliance)
bar
Min Pre-charge Pressure 0.5
litre
Max Capacity of CH System 125
Primary Water Content of
Boiler (unpressurised) 1.1

Temperatures
C.H. Flow Temp (adjustable)
35°C to 85°C max (±5°C)
LPG Gases Propane - G31
Burner Injector 15 x 0.77mm diameter
Burner Pressure Max Rate Min Rate
Propane mbar 34.4 ±0.5 5.1 ±0.5
in wg 13.8 ±0.2 2.0 ±0.2
Inlet Pressures
mbar 37
in wg 14.8
SEDBUK Declaration For System Boiler 60/100 IE
The seasonal efficiency (SEDBUK) is 78.2 %
This value is used in the UK Government's Standard Assessment Procedure (SAP) for
energy rating of dwellings. The test data from which it has been calculated have been certified
by 0051.
Page 8
5.0 Dimensions and Fixings
Dimensions
A780mm
B345mm
C450mm
D107mm Ø Min.
E200mm

F190mm
G143mm

Page 9
6.0 System Details
6.1 Central Heating Circuit
1. The appliance is suitable for fully pumped SEALED SYSTEMS ONLY.
Treatment of Water Circulating Systems
• All recirculatory water systems will be subject to corrosion unless an appropriate
water treatment is applied. This means that the efficiency of the system will
deteriorate as corrosion sludge accumulates within the system, risking damage to
pump and valves, boiler noise and circulation problems.

• For optimum performance after installation this boiler and its associated central
heating system must be flushed. A means of achieving this is by following the
guidelines given in BS 7593 "Treatment of water in domestic hot water central
heating systems".
• This must involve the use of a proprietary cleanser, such as BetzDearborn Sentinel
X300 or X400, or Fernox Superfloc. Full instructions are supplied with the products,
but for immediate information please contact BetzDearborn ([phone]) or
Fernox ([phone]) directly.
• For long term protection against corrosion and scale, after flushing it is recommended
that an inhibitor such as BetzDearborn Sentinel X100, or Fernox MB-1 or Copal is
used. The correct dosing is obtained by following the guidelines given in BS 7593.
Failure to flush and add inhibitor to the system may invalidate the appliance
warranty.
• It is important to check the inhibitor concentration after installation, system
modification and at every service in accordance with the manufacturer's instructions.
(Test kits are available from inhibitor stockists.)
• For information or advice regarding any of the above contact Heatmerchants
Technical Enquiries on 090 - 6442303.
6.2 Bypass
1. The boiler is fitted with an automatic integral bypass.
6.3 System Control
1. The boiler is designed for use in a heating system that incorporates external controls, i.e. a
minimum of a timer device.
Page 10
6.4 System Filling and Pressurising
1. A filling point connection on the central heating return pipework must be provided to
facilitate initial filling and pressurising and also any subsequent water loss
replacement/refilling.
2. The filling method adopted must be in accordance with the relevant Water Supply
regulations and use approved equipment. Your attention is also drawn to the current edition of
I.S. 813.
3. The sealed primary circuits may be filled or replenished by means of a temporary
connection between the primary circuit and a supply pipe provided a 'listed' double check
valve or some other no less effective backflow prevention device is permanently connected at
the inlet to the circuit and the temporary connection is removed after use (Fig. 3).

Fig. 3
4. There are connection points on the mains cold water inlet and central heating return
isolating taps to which the optional filling loop can be assembled.
6.5 Expansion Vessel
1. The appliance expansion vessel is pre-charged to 0.5 bar. The vessel is suitable for correct
operation for system capacities up to 125 litres. For greater system capacities an additional
expansion vessel must be fitted -refer to the current edition of I.S. 813.
6.6 Pressure Relief Valve (Fig. 4)
Fig. 4

1. The pressure relief valve is set at 3 bar, therefore all pipework, fittings, etc. should be
suitable for pressures in excess of 3 bar.
2. The pressure relief discharge pipe should be not less than 1/2" dia, run continuously
downward, and discharge outside the building, preferably over a drain. It should be routed in
such a manner that no hazard occurs to occupants or causes damage to wiring or electrical
components. The end of the pipe should terminate facing down and towards the wall.
3. The discharge must not be above a window, entrance or other public access.
Consideration must be given to the possibility that boiling water/steam could discharge from
the pipe.
Page 11
7.0 Site Requirements
7.1 Information
The installation must be carried out by a Competent Person and installed in accordance with
the current edition of I.S. 813 "Domestic Gas Installations", the current Building Regulations
and reference should be made to the current ETCI Rules for Electrical Installation.
7.2 Codes of Practice
Standard Scope
I.S. 813 Domestic Gas Installations.
BS 5546 Installation of hot water supplies for domestic purposes.
BS 5449 Part 1 Forced circulation hot water systems.
BS 7074 Expansion vessels and ancillary equipment for sealed water systems.
BS 7593 Treatment of water in domestic hot water central heating systems.
WARNING - The addition of anything that may interfere with the normal operation
of the appliance without the express written permission from the manufacturer or his
agent could invalidate the appliance warranty.
7.3 Clearances (Figs. 5 & 6)

Fig. 5