High R1/R2 Readings & Poor CPC Continuity Explained

If your EICR failed in London and your report mentions high R1/R2 readings or poor CPC continuity, it can feel like you’ve been handed a physics exam instead of a safety certificate.

But these results are actually telling a simple story:

• High R1/R2 usually means too much resistance somewhere in the circuit’s line and earth path, often caused by a loose connection, poor joint, damaged cable, or incorrect wiring.

• Poor CPC continuity means the earth path is not reliable, which can affect fault protection and the safe operation of protective devices.

In this guide, we’ll translate the jargon, show what causes these issues in real London properties, and explain how remedial work is typically done so you can get back to a satisfactory EICR without drama.

If you want to skip the reading and just get it sorted, start here:
https://londoneicrcertificates.co.uk/eicr-services/

What are R1 and R2 readings (in normal English)?

When an electrician tests a circuit, they’re checking that electricity can flow correctly and, more importantly, that fault current can flow back safely so protective devices can disconnect quickly.

• R1 is the resistance of the line conductor (live path)

• R2 is the resistance of the CPC / earth conductor (earth path)

When the report shows high R1/R2 readings, it usually means the circuit has extra resistance somewhere.

Extra resistance is a red flag because it can lead to:

• slower disconnection times during faults

• overheating at poor joints

• unreliable test results at certain points on the circuit

• higher risk of future failures or faults

What is CPC continuity (and why it matters)?

CPC stands for Circuit Protective Conductor which is basically the earth conductor that protects you if something goes wrong.

CPC continuity testing checks that the earth path is continuous from the consumer unit through each point of the circuit and back.

If CPC continuity is poor, you might have:

• a disconnected earth at a socket or switch

• a broken or damaged earth conductor

• an incorrect joint hidden under floors/ceilings

• mixed or old wiring where the CPC is missing in parts of the circuit

This is one of the reasons an EICR becomes Unsatisfactory, because earth continuity is a core safety function.

If you want a simple walkthrough of how to read an EICR like a pro, this is the best page:
https://londoneicrcertificates.co.uk/how-to-read-an-eicr-report-and-ensure-electrical-safety-in-london/

Why these faults can fail an EICR in London

A London EICR is not “just a tick box”. The report is testing whether:

• the installation is safe for continued use

• protective devices can operate correctly

• circuits meet the required safety criteria

High R1/R2 and poor CPC continuity can cause an EICR to fail because they can impact:

• earth fault protection

• disconnection times

• reliability of bonding/earthing

• risk of overheating at connections

And here’s the key: these results are often symptoms, not the final diagnosis. The real skill is finding where the resistance or continuity problem is coming from.

If you already have a failed report and need repairs + retest, go here:
https://londoneicrcertificates.co.uk/remedial-work-for-failed-eicr-certificates/

The most common causes we find in London properties

London housing is a mix of old installs, upgrades, conversions, and “creative DIY”. That’s why these issues pop up constantly.

1) Loose terminations (sockets, switches, consumer unit)

This is the number 1 reason. Even a slightly loose connection creates resistance.

Typical outcome:

• high R1/R2 at certain points

• inconsistent readings depending where you test

• sometimes heat marks behind accessories

2) Poor joints hidden under floors or above ceilings

Extensions to circuits are often done with junctions you can’t see. If the join is poor or corroded, you’ll see higher resistance.

Common in:

• Victorian conversions

• older flats with multiple refurb phases

• properties that had kitchens/bathrooms “updated fast”

3) Damaged cables from renovations

We see this a lot with:

• downlights and ceiling work

• kitchen units fixed into walls

• bathroom mirror/shaver socket wiring

• wardrobes fitted without checking cable zones

If a cable is nicked, crushed, or partially cut, resistance can rise and CPC continuity can fail.

4) Missing or unreliable CPC on lighting circuits (older installs)

Some older lighting circuits either:

• have no CPC in parts of the run, or

• have CPC present but not terminated correctly at fittings

This is especially common with older ceiling roses and metal light fittings.

5) Earthing and bonding issues

Sometimes the CPC continuity failures are linked to bonding/earthing arrangements that aren’t correct or are incomplete.

If you’re a landlord trying to stay compliant, this page is the right fit:
https://londoneicrcertificates.co.uk/eicr-certificates-for-landlords-in-london/

If you’re a homeowner, start here:
https://londoneicrcertificates.co.uk/eicr-certificates-for-homeowners-in-london/

For commercial properties:
https://londoneicrcertificates.co.uk/commercial-eicr-certificates-in-london/

What counts as a “high” R1/R2 reading?

There’s no single magic number because it depends on:

• circuit length

• cable size

• number of points

• installation design

But in practice:

• if the reading is significantly higher than expected for that circuit type and length, it indicates abnormal resistance

• abnormal resistance almost always comes from a connection issue, joint issue, damaged cable, or incorrect conductor path

This is why experienced testing matters. You need someone who can interpret the results and trace the fault properly, not just write numbers on a report.

How we diagnose high R1/R2 and poor CPC continuity properly

When we attend remedial jobs after an EICR fail, we don’t “guess” or swap random sockets. We follow a method.

Our process (the actual steps):

1. Review the EICR observations and the circuits affected

2. Re-test the circuit to confirm repeatability of the results

3. Narrow down the fault by testing at multiple points (start, mid, end)

4. Inspect accessible accessories (sockets, switches, fittings)

5. Check termination quality at the consumer unit

6. Identify any suspect joints, spurs, or renovations

7. Fix the root issue

8. Re-test and record compliant results for confirmation

That’s how you stop the same issue reappearing on the next EICR.

What remedial work usually looks like

Common fixes we do:

• re-terminate loose conductors correctly

• replace heat-damaged accessories

• correct incorrect spurs/junctions

• locate and repair damaged cable sections

• improve earth continuity on affected circuits

• correct bonding/earthing faults where required

• re-test and confirm compliant readings

If your priority is speed and minimal hassle, our remedial service is here:
https://londoneicrcertificates.co.uk/remedial-work-for-failed-eicr-certificates/

Case studies (realistic London examples)

Case Study 1: “High R1/R2” on sockets after a kitchen refurb

Property type: 1–2 bed flat, London
Issue: EICR failed due to high R1/R2 readings on ring final circuit
Cause: Poor termination on a spur added during kitchen works
Fix: Re-termination + replacement of affected accessory + re-test
Result: Stable readings, circuit compliant, EICR updated

Case Study 2: “Poor CPC continuity” on lighting circuit in a conversion

Property type: Victorian conversion split into flats
Issue: CPC continuity poor on upstairs lighting
Cause: Mixed older wiring, CPC missing/incorrectly terminated at fitting
Fix: Corrected CPC path + improved terminations + re-test
Result: CPC continuity confirmed, report updated

Case Study 3: Multiple faults, tight deadline for property manager

Property type: Managed property in Central London
Issue: Poor CPC continuity + inconsistent readings
Cause: Multiple loose terminations + hidden junction creating bad joint
Fix: Remade connections in compliant enclosure + full re-test
Result: Consistent results and successful compliance outcome

Want to show trust and proof? Add a few project photos to your Our Projects page too:
https://londoneicrcertificates.co.uk/our-projects/

Why remedial work isn’t always done immediately after inspection

A lot of clients ask why we don’t fix everything on the spot. Sometimes we can. But often it’s not professional or efficient.

Reasons:

• The inspection engineer’s job is accurate testing and reporting

• Remedials may need approval from landlord/agent

• Materials may be required (and quality brands matter)

• A proper quote avoids surprise costs and confusion

We explain this properly here:
https://londoneicrcertificates.co.uk/blog/why-eicr-remedial-work-is-not-done-immediately/

What to send us so we can fix it fast (no back-and-forth)

If you want the fastest route to a fix, send:

• your EICR report (PDF or photos)

• property type (flat/house/HMO/commercial)

• postcode (for parking/congestion planning)

• urgency (tenant moving in, renewal, sale, insurance)

• access details and preferred time slot

Then we can route you to the right engineer and get it done smoothly.

Book an EICR in London or fix a failed one

If you need a new EICR or you’ve failed due to high R1/R2 or poor CPC continuity, we can help across London.

Start here for booking and service details:
https://londoneicrcertificates.co.uk/eicr-services/

If you already have a failed report and need remedial work:
https://londoneicrcertificates.co.uk/remedial-work-for-failed-eicr-certificates/

For cost expectations and what affects pricing:
https://londoneicrcertificates.co.uk/eicr-certificate-cost/

Final word

High R1/R2 and CPC continuity issues look complicated, but in most cases they come down to a few real-world causes: loose connections, poor joints, damaged cables, mixed wiring, or missing earth continuity.

The difference between a fast fix and a stressful one is simple: proper diagnosis + proper re-testing.

If you want it handled properly, we’ve got you.