Mamiya C28, C32, C24 manual GAS Valve Replacement, Expansion Vessel Replacement

Page 40

SERVICING

SERVICING

55 GAS VALVE REPLACEMENT

Check

1Disconnect the electrical supply.

2 Remove the front casing panel.

3Disconnect the connector A and check the electrical resistance of the coil referring to the following diagram

On---off operator approx. 4 180 Ω*

* at ambient temperature.

4If the resistance of the coil is different from the value stated by ±10% or greater, replace the unit as described below.

Replacement

5Turn off the gas supply at the gas service cock and disconnect the electricity supply.

6Remove the front casing panel (refer to frame 42).

7 Disconnect the connectors A and B.

56WATER TEMPERATURE---PRESSURE GAUGE REPLACEMENT

1Disconnect the electrical supply.

2Remove the front and right hand side casing panels (refer to frame 42).

3Release system pressure by opening the main circuit drainage cock A

Do not release CH pressure using the pressure relief valve. It may cause debris within the system to foul the valve.

4Remove the fork B and the probe holder spring C.

5 Pull out the control panel (see frame 30).

6Squeeze the tabs D to release the temperature---pressure gauge E and remove it.

7Re---assemble in reverse order.

8Disconnect the earth wiring from the gas valve.

9Unscrew the connectors C and remove the pipe D

10 Unscrew the inlet connector.

11 Unscrew the screws E and remove the valve.

12Fit the new gas valve in reverse order ensuring new gaskets are fitted and check for gas tightness.

13Check the operation of the boiler.

C

D

A

B

E

E

C

B

D

A

57 EXPANSION VESSEL REPLACEMENT

valve. It may cause debris within the system to foul

 

the valve.

If the CH expansion vessel is faulty, there are 2 options:

AIf it has a punctured diaphragm, but is otherwise leak free, than it can be left in place and a new vessel added to the return side of the system, external to the boiler, provided it is of adequate capacity and pre---charge pressure.

BIf there is at least 400 mm (16”) clearance above the boiler, the expansion vessel can be changed without removing the boiler (rear exit flues will have to be disturbed).

For option B, proceed as follows:

1Disconnect the electrical supply.

2Gain access to the controls area by removing the boiler front panel (refer to frame 42).

3Close off the isolating cocks of the CH circuit at the bottom of the boiler.

4Release system pressure by opening the main circuit drainage cock.

Do not release CH pressure using the pressure relief

5Completely unscrew the connection A, the locknut B and remove the expansion vessel from the top of the boiler.

B

A

6Re---assemble in reverse order.

40

mini HE --- Installation & Servicing

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Contents Installation and servicing Mini HE --- Installation & Servicing Document Amendments General Boiler DataPerformance Data --- Central Heating Domestic Hot WaterContents Benchmark Commissioning Checklist DetailsGeneral Boiler Water Connection Boiler ClearancesGAS Safety IntroductionOptional Extra Kits Safe HandlingFlue Installation Requirements GAS SupplySafe Handling of Substances Location of Boiler and Flue OutletWater Circulation System Water TreatmentAIR Supply Additional PumpsElectrical Supply RequirementsSize of expansion vessel Mini HE C24, mini HE C28Hydraulic Loss Remaining pump capacity General Boiler Control Interlocks Domestic HOT Water RequirementsGeneral Boiler Water Circuit Diagram Installation Installation Boiler AssemblyInstallation Unpacking Pack a contentsHardware pack contents Pack B contentsInstallation Fitting the Flue SystemRear Flue Assembly Refer to the following diagram for the model mini HE C32Twin Pipe Flue DuctWall Mounting Template rear flue Ring Installation Cutting the FlueFitting the Extension Kits Installation Fitting the Optional Roof Flue Roof Flue KIT CONTENTS/OPTIONSInstallation Flue Terminal Position Flue ArrangementAssembling the Roof Flue KIT Flue over 3 meters longInstallation Fitting the Wall Mounting Plate Fit the service valves, washers and tail pipes as shownMounting the Boiler ConnectionsSafety Valve Drain Condensate DrainLocate the gasket and flue turret on the top of the boiler Flues over 1 meter longIncoming mains wiring detail For external controls wiring see frameElectrical Connections Pictorial Wiring Installation Functional Flow Diagram Control pcbExternal Electrical Controls Electrical Connections for a Combi BoilerInstallation Initial Lighting Maximum valve setting To Adjust PressuresMinimum valve setting Anti Cycling Setting Commissioning and TestingElectrical Installation Gas InstallationGeneral Checks Installation GAS Conversion Handing OverServicing Servicing ScheduleServicing Removal of Outer and Inner Casing Servicing Burner Removal and Cleaning Cleaning the Heat ExchangerRE---ASSEMBLY Burner Pressure CheckServicing FAN and Venturi Removal and Cleaning Remove the fan by sliding it towards left see the arrowSpark and Detection Electrode Replacement Burner ReplacementBurner Injectors Replacement When replacing any componentServicing Overheat Thermostat Replacement Flue Temperature Probe ReplacementTemperature Probe Replacement Removal of CH temperature probeGAS Valve Replacement Expansion Vessel ReplacementVenturi Replacement Servicing FAN ReplacementAIR Pressure Switch Replacement Pump Replacement Complete Servicing Electronic CONTROL/IGNITION PCB Replacement Boiler mode setting Servicing CH Flow Switch Replacement CH Flow Switch Membrane ReplacementDHW Filter and Flow Limiter Replacement Servicing DHW Flow Switch ReplacementFlow limiter Servicing Primary Heat Exchanger Replacement Recuperator ReplacementServicing Diverter Valve Actuator Replacement Diverter Valve Internal Parts ReplacementServicing DHW Heat Exchanger Replacement CH Drain Cock ReplacementTo clean the condensate trap and drain Condensate Trap ReplacementTo replace the condensate trap Normal operation OFFFault Finding FindingFrom Fault finding Fault Finding Fault Refer back to page 52 of fault finding to continue Fault Finding From Burner mod. mini HE C28, mini HE C32 075535Fan mod. mini HE C28, mini HE C32 17398422 23 Installer Notification Guidelines GAS Boiler Commissioning Checklist Service Interval Record Technical Training Ideal boilersInstaller Water hot or Installer the contact fire not doesCorrectly Ignition at attempt Cleaning MaintenanceGAS of Escape Boiler the Light to Lights DiagnosticClearances Minimum

C28, C24, C32 specifications

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