01752 201077

07528 889733

Commercial & Industrial Electrical Testing & Fault Finding Covering Plymouth, Devon & Cornwall

Fault finding - tracing electrical faults

Quite often when you go to use an appliance and find it not working the problem can be easily located and resolved. The usual reaction is to head to the fuse box to see if a blown fuse needs to be replaced. Often a fuse has blown but replacing it will not always resolve the underlying issue that caused the fuse to blow in the first place. Occasionally fuses can blow for no obvious reason, but often replacing the fuse only allows you to use the appliance for a short while before the replaced fuse blows again.

The investigating and locating of electrical faults can usually be a methodical process of working through the electrical system and eliminating possible causes one by one until the fault is found. However more serious faults may be trickier to locate and professional help is often needed in these incidences.

Often people try to source the cause of the problems themselves in the hope to save money by not calling in a professional for help. It is very important to never put yourself at risk when it comes to electrical safety and always follow the precautions listed below:

Commercial testing
Industrial testing

Your safety must always come first

As mentioned above, it is advisable that with any electrical fault you seek professional advice immediately. If you do however choose to try to locate to source of the problem yourself then it is paramount that you put your safety first. It is vital to remember that even if only one appliance is affected you must still switch off the main power at the consumer unit. Many people think that switching off the power of the socket that the appliance is plugged into will stop any power getting to the appliance, but it could be a real possibility that the fault lies with the switch itself and therefore not isolate the power to the appliance at all. It is advised you ensure you have all the suitable equipment needed before attempting any work on electrical circuits. This kit should include the following at a minimum:

Make sure you keep your electrical tool kit somewhere that is easy to gain access to should there being an electrical fault such as a power cut and ensure you have a torch that offers enough light should the power go off in the middle of the night. Ensure that the kit is not tampered with or items used out of the kit and not replaced, as you will want to ensure you have all these items to hand when they are needed.

Checking for faults

When an appliance or light stops working make sure you check all the obvious causes first to illuminate the most likely causes. These include making sure there is not a power cut to the local area, replacing a bulb in a light not working and if you are on an electric pay meter that you have sufficient credit. If none of the above applies and you are sure there is a genuine fault, you can now begin a methodical way of checking what the other causes could be.

Faults can be located in several places along the circuit, anywhere from the appliance having developed an internal fault to the socket, switch, ring main fuse box or within the circuitry. It is now vital to check each of the possible faults one by one as to rule out the possible causes one by one.

To check to see if there is a fault with an appliance you can try plugging the appliance into a different working socket. If the appliance does work when plugged into a different socket then the appliance is not the fault and you can move on to checking the other possible causes.

If the appliance fails to work then a fault with the appliance could be the reason but there is the possibility of the second socket also being faulty especially if it on the same ring main as the original socket or a problem with the appliance plug sure as a loose wire or blow plug fuse. To check the appliance plug, unplug the appliance and using a screwdriver unscrew the plug to expose the wires and fuse. Ensure you check all the wire flexes, make sure none are damaged or shorn, if they are then strip the outer plastic to expose undamaged flex and reconnect. If a fuse is present within the plug then replace with a new fuse. Make sure all flexes are correctly anchored before reconnecting the plug. Also check along the flex of the appliance to ensure there has been no external damage to the flex which may have broken the connection. Once you have done this you can retry the appliance in the socket, if the appliance works then you have correctly identified and corrected the fault.

Similar measures can be taken if there is a fault with your lighting system, once you have changed the bulb to ensure that isn’t the cause, you can (ensuring all power is switched off at the fuse box) check along the flex from the pendant to the ceiling, taking off the pendent casing you can check all flex and wiring to ensure all connections are complete with no frayed wires. If you notice any damage to any of the flex or wires then ensure you replace with undamaged flex and then reconnect to see if the fault has been rectified.

Checking the fuses and mending blown fuses

There are two main reasons for fuses being blown, these can be either overloading the fuse with too much demand being placed on it, usually from too many appliances melting the fuse, or from short circuiting when the wiring is faulty and causes a current surge.

If the cause for the fuse to blow is that the fuse has been overloaded it is very easily fixed. First turn off the power supply to the affected circuit, unplug all appliances on the circuit and replace the blown fuse with a new one. Make sure if the fuse did blow due to overloading that you reframe from overloading the circuit again by avoiding having too many appliances plugged into the circuit again.

If the cause of the blown fuse was a short circuit, this can be a bit harder to rectify. First you will need to find the cause. First turn off the power by the main switch, now remove each fuse individually until you have found the location of the blown fuse.

Once the blown fuse has been located be sure to remove all of the old fuse wire, then replace with a new fuse wire to the correct amp. If you are replacing a fuse from a lighting circuit then use 5A, if you are replacing a fuse from a circuit for an immersion heater then use 15A, and if replacing a fuse in a ring circuit then use a 30A wire. When replacing the wire ensure you connect the fuse wire carefully to both terminals before trimming any long ends off. Once you have replaced the wire you can place the new fuse back into the consumer unit and turn on the main switch again to test the fuse. If replacing the fuse wire doesn’t work and the fuse blows again, providing you have already checked that none of the appliances or lighting are causing the fault then you can assume you have a circuit fault.

Checking for circuit faults

If you have already checked of any faults with appliances, lighting, pendants, appliance fuses and consumer board fuses then it is likely the fault lies within the fixed wiring from the consumer box to the sockets. This may prove very difficult to track and may very well be when you really need to call in a skilled electrician who can trace each network of wires to find the source of the fault.

The most common cause of faults within the fixed wiring is due to damage of the cables or the connection terminals within the socket. The most common cause of damage to the cables within the fixed wiring can be age related degeneration where the sheath protecting the cables may have become damaged over time causing wires to become exposed which in turn can lead to a circuit fault when two wires come in contact with each other. Another reason for damage to the fixed wiring can be due to accidental damage caused by general DIY like drilling into a wall or nailing into floorboards. It is important when carrying out any DIY that includes drilling or hammering into walls, ceilings or floors that you track where possible electrical cables could be to avoid damage occurring to electrics. If you suspect where the damage to a fixed cable may be then it can be rectified relatively easily, first you need to gain access to where the damage is, once you have found the damaged cable and turned off power to the circuit at the consumer unit you can now cut out the damaged cable and reconnect with new cable using a three junction terminal block. This can also be done for damaged fixed wires within plaster however you will obviously need to gain access to the damage by removing the plaster and making good once you have fixed the damaged cable. If however the damage to the fixed wring is due to aging and you are finding faults occurring quite often, rather then wasting your time trying to track and repair the wiring each time you really need to contact a qualified electrician who can talk to you about the need to rewire.

If the fault is due to damage at the terminal connections within an appliance these are usually quite easy to find and repair. It is just a case of methodically removing each of the faceplates of the circuit (remembering to ensure you have turned off the power to the socket at the consumer box) and inspecting all the wiring. You need to first ensure each wire is corrected anchored to its terminal connector, if any wires have become loose then cut the wire, remove a short amount of sheath and reconnect to the terminal connector. If all wires appear to be correctly anchored to the terminal connectors then next check the sheath of the wires. The sheath should only be striped enough for the wires to be anchored to there terminal connectors, if the sheath of the wires has been excessively striped this can cause a circuit fault when two wires can touch causing a fault. If you can see any bare wires touching then make sure you recut the cables and re sheath the wires before reconnecting the terminal connectors.

If after all checking you are still unable to find the location of the fault then we strongly urge you to seek professional advise from a qualified electrician.

Inspection & testing - electrical safety

As a provider of services, or an owner of commercial or private property you have a legal requirement to ensure the electrics contained within the property meet the correct safety standards.

Not only should you have your electrics tested using a full EICR, electrical installation condition report periodically when needed, it is important to remember that the electrics are tested and visually inspected at regular set intervals by a skilled electrician in accordance with set building regulations. Should any concerns be raised these should be addressed as a matter of urgency and repairs conducted by a skilled and qualified electrician.

With regards to an Electrical installation condition report (EICR), this too can only be completed by a skilled electrician and involves a full visual inspection of all the electrics on site alongside a set of live and dead electrical testing. Once complete an EICR will be issued which will list any faults that have been found. It is also possible to provide a separate quote listing the cost for each repair to be undertaken.

EICR faults can be categorised as:


If any faults are found on the EICR which lead to further inspection or electrical work being undertaken it is important to note a further EICR will need to be done once the work is completed which should now show up as no faults found. Once no faults have been found you will be issued with a satisfactory report certificate. The certificate will state that the electrics are now of a satisfactory condition and will state when the EICR should be repeated, this date should also be marked on the consumer unit.

How often do EICR's need to be completed?


You will also need to get an EICR done if there is a change of use of the property, and additions to the property which may make it prone to overloading, problems occurring within the property such as shocks, overloading, tripping or blowing of fuses, or if there has been any water damage or leaks within the property.

Why do I need to have an electrical installation condition report?

You need to have an EICR is to conform with British Standards 7671, which states all electrical installations need to be periodically inspected and tested. You also have a responsibility to ensure all the electrics within a building of you possession or tenancy are safe for all those who may work or reside within the property. Electrical caballing and circuits do deteriorate over time, which can cause them to become unsafe for use. Without a periodic electrical installation condition report, which aims to find any faults developing before they become unsafe, it may not be until someone receives a shock or burn before any faults are detected, which could lead to serious disability or death in the most serious incidence. The EICR report and satisfactory certificate issued stating the electrics are safe will also provide protection to the property should a defect arise that leads to a property fire.

What is involved in an electrical installation condition report?

When an EICR is complete the report will document the following information:

How long does an electrical installation condition report take to complete?

This answer is hard to predict as it is dependant on a lot of factors including the size of the property and if any faults are found. On average, the time expected to complete an EICR on a domestic three-bedroom property is up to 4 hours. This does however depend of if any faults are found. The minimum time taken for any EICR including the smallest of properties should be 2 hours. The regulations state that the minimum number of checks made on an installation is 10% of the total installation, this percentage is negotiable between the electrician and property owner as to how far the checks go past 10% but is obviously subject to an increased price and as to whether the owner wants floor boards or carpets removed. It is important to note that within testing 10% of the installation that if a fault is found then the regulations state a further 10% of the installation be inspected and to inform the owner that further inspecting needs to be undertaken. During the visual part of the inspection limited dismantling may need to occur but again this can be discussed with the owner to keep any disruption to a minimum.

How much will an electrical installation condition report cost?

This is again a figure that is affected by several different factors. Before a EICR is conducted we will be able to give you a quote of the report, but it is important to remember that should any faults be discovered and more investigation needed, our qualified electrician will make you aware of this as soon as possible and we will be able to let you know any additional costs this may incur.

Factors that affect the cost of the Electrical Installation Condition Report include:

Information we will need to carry out your Electrical Installation Condition Report

The following information will be needed in order to complete and issue a satisfactory test certificate. It would be beneficial for you to have the following information to hand in order to save delay in obtaining your certificate:


It is also important to ensure all occupants are aware that the EICR is being done and to expect our presence so we can gain entry. If the property is vacant it is important we are supplied with keys so we can access all areas needed to carry out the report. It is important you provide us with any parking permits should they be required and ensure there is enough electric on the prepayment meter or a current supply of electric to the property in order for us to carry out any live testing. Should we not be able to obtain entry to the property or there be no electric supply, we will not be able to carry out the inspection and it will need to be rebooked at your expense.

Please note no report will be issued until full payment for the EICR has been received.

Fault finding
Testing tools

Testing codes - C1, C2, C3, & FI in fixed wire testing.

Should you require an Electrical Installation Condition Report to be carried out on your domestic or commercial premises it may be useful to familiarise yourself with how the report will be presented to you. Ideally you will hope to receive a report indicting that no faults have been found during testing and a fully electrical safety certificate for the premises can be issued. Unfortunately this is not always the case, during the EICR the electrician will carry out a number of tests on the consumer units, circuits, lighting, appliances and other electrical sources at the property. During these tests the electrician will make a number of observations and report any faults that have been found. These faults are categorised according to how severe they are and how soon action needs to be taken. It is a legal requirement to report and categorise these fault correctly so the appropriate course of action can be taken to ensure the electrics within a property are safe to use by the occupants of that property. Any faults found on the fixed wiring of the property are coded using codes C1, C2, C3 and F1.

EICR faults can be categorised as:

C1 Faults – requiring urgent attention. This code is the most severe and indicates that danger is present and immediate steps should be taken to rectify these faults. These faults need to be presented to the property owner both written and verbally to ensure they are aware of how serious the fault is and that there is a high risk of injury.

C2 Faults – improvement required. A fault categorised at a C2 should still not be ignored, while the fault does not pose an immediate danger it is likely to become dangerous in the future and become a C1 fault.

C3 Faults – does not comply with BS 7671 but is not unsafe. This type of fault means that it does not comply with current regulations but does not pose any harm to the property occupants, although these faults may need some further attention to rectify them a report containing C3 faults is not necessarily considered unsatisfactory.

F1 Code – further investigation needed, not to be ignored. This may occur in the instance that the electrical contractor has noted something to bring to your attention that is not covered within the report. For instance the electrician may have noticed faulty or dull lights within your emergency exit signs so will report this as an F1 fault indicating further investigation is needed. A report containing just F1 faults would be considered unsatisfactory.

In order to achieve an electrical compliance certificate you would need to address all C1, C2 and F1 code faults. However it would make good practise to address and rectify all faults including C3 found on the EICR.

You do not have to get the same electrical contractor to carry out the repairs as you used for the EICR. Once the faults within the system have been corrected you would not require the whole installation to be retested. The electrician that carries out the repairs should issue you with the correct paperwork to show that he has corrected the faults on the EICR by issuing you with an electrical installation certificate or minor works certificate which when presented together with the original EICR that indicated the observed faults will show that the faults have been rectified with accordance to BS7671 regulations.

How to address a C3 fault?

Some electricians argue that a C3 code is not very helpful, it is neither here nor there in the sense that although the fault is not considered a danger or risk at present, it may become a C2 OR C1 fault over time and there is no way of knowing how long that process may take. Therefore if you have a C3 code fault on you EICR it may be hard to know how to address the fault. It is important to understand that while a C3 fault does not pose an immediate danger to those residing or using the property, it does not comply with the latest electrical regulations. Although there is no obligation for the property owner to rectify any C3 faults, and while C3 faults alone will not mean an unsatisfactory electrical report, it would be advisable and good practise to address all faults be it C1, C2, C3 or F1 as soon as you are made aware of them.

Fraudulent coding

Ultimately the coding system within the EICR is designed to ensure those working or residing within the property are able to use the electrics safely and with no risk of injury.

There have been times electricians have been asked by owners to change a C2 code to a C3 to avoid the expense involved with having the required work carried out and to obtain a satisfactory EICR. This act is one of fraud and if found guilty would hold serious ramifications for both the electrician and owner. Electricians should be given the ability and freedom to code any faults they find on the EICR as they see fit and not be pressurised by supervisors or property owners in changing codes to reduce outlay or to achieve a satisfactory report when in fact the electrics are deemed unsafe.

At Acorn Electrical & Mechanical (AEM) we pride ourselves in our excellent standards. Not only do we ensure our compliance within electrical testing, inspection and fault finding but we also pride ourselves in providing our customers with the best service at the most competitive prices.

The Electricity at Work regulations 1989 states that we must 'take all reasonable and practical steps to prevent danger from electrical systems'. All our staff are trained to the highest of standards, continued learning is something we take very seriously and all our workers are regularly assessed to ensure they are working at the correct level. Safety is of most paramount importance to us, both to our customers and our employees.

To ensure both safety to our employees and customers, we are governed by legalisation from The Health and Safety at Work Act 1974, the Workplace regulations 1992, the management of Health and Safety Work Regulations 1999 and the Provision and Use of Work Equipment Regulations 1998.

We are one of the leading companies for electrical testing and inspections, our highly experienced and skilled staff ensure that all testing and inspecting is fully comprehensive and compliant with all legalisation. We have vast experience in all forms of electrical testing from small privately owned properties to large retail infrastructure and hospitality properties.

Electrical Installation Condition Report (EICR)

Electrical testing is an important procedure, all providers of services and property owners have a legal requirement to ensure the electrics within their property are safe for those residing or working within the property. An electrical installation condition report is an essential test that needs to be done at intervals determined by the nature and use of the property. The EICR alongside the electrical test certificate forms a legal document, with the EICR listing any faults present on the electrical system. As a provider of services, or an owner of commercial or private property you have a legal requirement to ensure the electrics contained within the property meet the correct safety standards.

Not only should you have your electrics tested using a full EICR, electrical installation condition report periodically when needed, it is important to remember that the electrics are tested and visually inspected at regular set intervals by a skilled electrician in accordance with set building regulations. Should any concerns be raised these should be addressed as a matter of urgency and repairs conducted by a skilled and qualified electrician.

With regards to an Electrical installation condition report (EICR), this too can only be completed by a skilled electrician and involves a full visual inspection of all the electrics on site alongside a set of live and dead electrical testing. Once complete an EICR will be issued which will list any faults that have been found.

We are highly experienced in carrying out EICRs and completing any necessary work that may be required should faults be found. We are happy to come and provide a no obligation quote for an electrical Inspection condition report to be done at your property. It is also possible to provide a separate quote listing the cost for each repair to be undertaken should any faults be found during the EICR. We are also very aware that you may have concerns about how having the EICR testing may interfere with those residing or working at the property. We are more then happy to listen to any concerns you may have and work with you to find the most convenient time for the EICR to take place so it has as little impact on your daily life or running of your business as possible.

Landlord electrical testing services

We have a wealth of knowledge and experience with regards to the legal requirements landlords must meet when ensuring their rental property is safe for use. Not only providing the standard EICR which needs to be completed at a minimum of every 5 years or at every change of occupancy, we also offer periodic inspection reports. These reports ensure that residents occupying the property have not installed any electrical devices in an unsafe manner. It also provides the opportunity for the residents to raise any problems or concerns about the electrics they may have, whether it be fuses blowing, any tripping of the electrical circuits or any shocks they may have received. All our electrical inspectors carry full identification and are uniformed to ensure your residents safety and piece of mind. We are also happy to work alongside your assigned estate agents to minimise disturbance to yourself and are happy to collect keys from them in order to gain access to the property should that be more desirable.

Any reporting that takes place is always fully reported and documented as legally required and will always be carried out by fully qualified and competent electricians.

PAT testing

We also offer PAT Testing as required. This is the inspection and testing of appliance equipment. This testing is to inspect the condition of the appliance, plug and lead to ensure it is running correctly. Prices vary but we are happy to provide a full no obligation quote.

Why Choose Acorn Electrical & Mechanical

We are based in Plymouth Devon so we cover the complete South West. We have a team of skilled electricians who are passionate about their work and have been doing it for over 15 years.

Our team offers:


Please feel free to call us for help or advice.

If you are interested in booking a survey for any of our services or just a safety check, please contact Acorn Electrical & Mechanical (AEM) and a member of our team will be happy to help or advise you. CALL now on 01752 201077 or 07528 889733

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