Unit 315 Session 7 ​Diagnosing & rectifying faults in cold water

​DIAGNOSING AND RECTIFYING FAULTS IN COLD WATER SYSTEMS AND COMPONENTS

​Whenever mechanical or electrical components are installed on a cold water system, the risk of breakdown and failure is ever present.

Periodic preventative maintenance can alleviate some of these problems, but occasionally components simply wear out and must be replaced.

Poll

Have you been involved with the repair of a plumbing system or component?

• YES

• NO

Poll

We're you able to rectify the fault yourself?

• YES

• NO

Open Ended

When arriving at a property where a repair is needed for the first time, what would be the best way of gaining valuable information about the fault?

​Identifying system faults through consultation with the customer

​When identifying faults that have occurred on cold water systems, the customer can prove an invaluable source of information as they can often describe when and how the fault first manifested itself and any characteristics that the fault has shown.

​Verbal discussion with the customer often results in a successful repair without the need for extensive diagnostic tests

Open Ended

Make a list of the types of questions you may ask a customer to gain information about a fault

(Make sure to use appropriate language and tone)

​The customer should be asked:

​● The immediate history of the fault:

● When did it first occur?

● How did they notice it?

● What characteristics did it show?

● Did they notice any unusual noises? This may well indicate the type of component failure that has taken place.

● Did they attempt any repairs themselves? If so, what did they do? This is important because if repairs have been attempted, they may well have to be undone to successfully diagnose the problem.

● What was the result of the fault?
Again, this is an important aspect because it can often indicate where the fault lies.
For instance, if the customer has noticed a drop in flow rate or pressure, this might indicate a blockage, a blocked filter, scale growth or a mechanical fault, such as a loss of charge from an accumulator or a pump fault.

​Identifying system faults through consultation with the manufacturer’s instructions

​When attempting to identify faults with cold water systems, one of the most important documents to consult is the manufacturer’s instructions.

In many cases, these will contain a section on fault finding that will prove an invaluable source of information.

Fault finding using manufacturer’s instructions usually takes three forms

​● known problems that can occur and the symptoms associated with them

● methods by which to identify the problem in the form of a flow chart. These usually follow a logical, step-by-step approach, especially if the equipment has many parts that could
malfunction, such as a cold water boosting set

● the techniques required to replace the malfunctioning component

​An exploded diagram and replacement parts list may also be present for those components that can be replaced.

When ordering parts, it is advisable to use the model number of the equipment and the parts number from the replacement parts list. This will ensure that the correct part is purchased.

​https://www.heatingspareparts.com/boiler-diagrams/baxi/duo-spc-tec-spc-33-spc-he

​Follow the link below and look for the 'First line spares' tab at the top of the page.

​Answer the questions on the following slides

Multiple Choice

What is the correct part number for the 'Fan'?

• 554897

• 5121447

• 453261

• 886594

Open Ended

What component is shown in the picture

Multiple Choice

Which picture shows a 'Pressure switch'?

Multiple Choice

What component is shown in the picture?

• Heat exchanger

• Sensor-hall effect

• Pressure switch

• Pump 15-60

​Methods of repairing faults

​Routine checks on components and systems can help to identify any potential problems that may be developing within the system as well as keeping the system operating to its maximum performance and within the system design specification.

​Checks performed can include:

● Checking components for correct operating pressures and flow rates

● Cleaning system components (including dismantling and reassembly)

● Checking for correct component operation:

​The following slides show some common plumbing components, research common faults associated with each of these components and write your findings.

1 or 2 faults per component will do.

Open Ended

A float valve

Open Ended

Basin taps

Open Ended

A central heating pump

Open Ended

A (Base exchange) water softener