Baxi Potterton BBU 15 HE I, H, K, J L

12.0 Fault Finding

37

© Baxi Heating UK Ltd 2009

Check and correct if necessary

1. The mechanical set of the gas valve

(CO2 values - see instruction)

2. Flame sensing electrode and lead connections

3. Flame sensing electrode position

Flame current should be more than 0.5 μA

Replace PCB

YES

Replace flame sensing electrode

NO

Check the gas supply pressure:

For Natural Gas greater than

10 - 11 mbar

IReplace Safety Thermostat

YES

Overheat Thermostat or

Condensate Safety Float Switch

operated or faulty

Allow to cool. Continuity

across thermostat terminals

more than 1.5 ohm

2.

1.

HKJL

Press the Service Reset switch

for 5 seconds

Fan connections correct at fan.

PCB - X401 connector terminals 5,6,7 & 8

YES Replace fan

Temperature sensors faulty.

Cold resistance approximately

10kΩ @ 25° C (CH sensor)

(resistance reduces with increase in temp.)

NO Replace sensor

YES

If pump is running the heat exchanger could be

obstructed

Replace heat exchanger

1.

2.

Restore Boiler Control defaults

NO

Continuity across plug

terminals at 3 &4 of connector

X401 more than1.5 ohm

Replace PCB

NO

YES

Condensate drain system fault Check condensate system

and Pump

Replace Safety Float Switch

or wiring

NO

IMPORTANT:There is no limit to the number of repeated ‘Service Reset’

operations but the Boiler Control must be refreshed by ‘Restoring Boiler

Control Default’as descr ibed on p.34 following the final ‘Service Reset’ and

before the Boiler Control reset is re-used.

YES

Contents

Main 2 Natural Gas Building Regulations and the Benchmark Commissioning Checklist ISO 9001 FM 00866 Installer Notification Guidelines Legislation Codes of Practice, most recent version should be used IMPORTANT - Installation, Commissioning, Service & Repair Safe Manual Handling General Preparation Technique Remember Contents 1.0 Introduction 1.1 Description 1.2 Contents 2.0 General Layout 2.1 Layout (Fig. 3) 2.0 General Layout 2.2 Flue Kit (10m & 12.5m) (Fig. 3a) 10 3.0 Technical Data 3.1 Bermuda HE CBBU 15 HE 4.1 Water Circulating Systems 4.2 Treatment of Water Circulating Systems 4.3 Pipework 4.4 System Controls 12 4.5 Fully Pumped Open Vent System (Fig. 5) 4.6 Storage Systems 4.7 Sealed Systems (Figs. 6, 7 & 8) 14 4.7 Sealed Systems (cont) Initial System Pressure (bar) Expansion Vessel Volume (litres) 1.0 V x 0.11 1.0 V x 0.087 5.1 Builders Opening (Fig. 9) 5.2 Location 5.3 Fireplace Opening & Surround 5.4 Firefont Frame Extension Kit 16 5.5 Flue 5.6 Ventilation 5.7 Gas Supply (Fig. 11) 5.8 Electrical Supply (Fig. 11) 18 5.9 Condensate Drain - General 5.10 Condensate Disposal (Fig. 12) 5.10 Condensate Disposal (cont.) 5.11 Condensate Pump Operation 20 6.0 Boiler Internal Wiring - greygr 6.1 Boiler Internal Illustrated Wiring Diagram - brown - black - blue - white - yellow br bk b w y 7.1 Initial Preparation 7.2 Flue System 22 7.2 Flue System (cont.) 24 7.3 Siting the Boiler 12 7.4 Water Connections 3 N 7.5 Gas Connection 8.0 Completion & Commissioning 8.1 Completion 8.2 Commissioning the Boiler 26 8.0 Completion & Commissioning 8.2 Commissioning the Boiler (cont.) 9.0 Annual Servicing 9.1 Annual Servicing 28 9.0 Annual Servicing 9.2 Annual Servicing - Inspection 10.1 Changing Components 10.2 Spark Generator (Fig. 46) 10.3 Electrode Assembly (Fig. 47) 10.4 Condensate Pump (Fig.48) 30 10.5 Fan (Fig. 49) 10.6 Burner (Fig. 50) 10.7 10.8 Gas Valve (Fig. 51) 32 10.9 PCB (Fig. 54) 10.10 NTC (Fig. 53) 10.11 Safety Thermostat (Fig. 52) 10.12 Float Switches (Fig. 55) 11.0 Setting the Gas Valve 11.1 Setting the Gas Valve (CO2check) 34 NOTE: When instructed to operate the reset button, press and hold for 5 seconds to reset the boiler. 12.1 Initial Fault Finding Checks 12.2 Error Codes Page Fault Finding Solutions Sections A B C D E F I H K J L 13.0 Short Parts List Page Page Page GAS BOILER SYSTEM COMMISSIONING CHECKLIST CONTROLS ALL SYSTEMS CENTRAL HEATING MODE COMBINATION BOILERS ONLY SERVICE RECORD Service Provider SERVICE 1 SERVICE 3 SERVICE 5 9.0 Warranty & Service Please complete the boxes below DDMYY M