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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Image 40
Mamiya C28, C32, C24 manual GAS Valve Replacement, Expansion Vessel Replacement
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C28, C24, C32 specifications

The Mamiya C series is celebrated among photography enthusiasts for its unique twin-lens reflex (TLR) design, offering both a classic aesthetic and innovative features that set it apart in the world of medium format cameras. The C32, C24, and C28 models represent a range of technology and design advancements that cater to various shooting needs.

The Mamiya C32, introduced in the early 1970s, is renowned for its precision engineering and versatility. This model features interchangeable lenses, allowing photographers to switch between different focal lengths for creative flexibility. The camera supports 120 and 220 film formats, enabling higher film capacities for extended shooting sessions. An essential feature of the C32 is its built-in light meter, which enhances exposure accuracy by providing real-time readings. The camera's bright waist-level finder offers excellent viewing comfort and composition aid, attracting those who appreciate a more hands-on shooting experience.

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Lastly, the Mamiya C28 provides a perfect blend of portability and advanced capabilities. With its ergonomic design and improved lens coatings, the C28 offers enhanced image quality with better contrast and sharpness. Similar to its predecessors, it utilizes an interchangeable lens system but enhances user convenience through quick-to-use shutter speeds and aperture settings. The camera is also compatible with a range of accessories, such as flash units and close-up attachments, further expanding its creative potential.

In summary, the Mamiya C32, C24, and C28 each present unique features and technological advancements that cater to various types of photographers. Whether it's the precision of the C32, the compact convenience of the C24, or the versatile performance of the C28, these cameras maintain a special place in the hearts of medium format enthusiasts, showcasing the blend of craftsmanship and innovation that Mamiya is known for.
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