Consumer unit upgrade: what actually happens on the day
A fuse board replacement is usually a one day job, and the part people are least prepared for is that the existing circuits have to pass testing before the new board can be signed off.
Before the day
A proper quote follows a survey, not a phone call. We check the earthing arrangement, the main supply and tails, the condition of the existing circuits, whether main protective bonding to gas and water is present and adequately sized, and whether there is anything in the installation that will not pass testing once the new board goes on.
That last point is the one that catches people out with cheaper quotes. A new consumer unit is certified work, and the certificate covers the circuits connected to it. If a circuit fails insulation resistance testing, it cannot simply be reconnected and forgotten.
How the day runs
Power off in the morning, existing board removed, new board mounted and the circuits transferred one at a time with each conductor identified and tested as it goes back in. Bonding is upgraded where needed. Then full testing, labelling, and the certificate.
- Power off for most of the working day, so plan around freezers and home working
- Circuits identified and labelled properly, which many older boards never were
- Main protective bonding checked and upgraded where undersized
- RCD or RCBO protection provided for circuits that require it
- Full test results recorded and an Electrical Installation Certificate issued
Why remedial work sometimes appears mid-job
Modern boards provide RCD protection that older rewireable boards never did, and that protection is unforgiving of faults that were previously invisible. A slightly damp outside light or a deteriorating cooker element that the old board tolerated will trip a new RCD immediately.
This is not an upsell, it is the protection doing its job and exposing an existing fault. We survey to reduce the surprises, and where something does appear we explain it, show you the readings and price the fix in writing before continuing.
What you are left with
A board with the correct protection for the circuits present, properly labelled ways so the next person can find the right breaker, upgraded bonding where it was needed, and an Electrical Installation Certificate with a full schedule of test results. That certificate is the document that matters when you sell, insure or let the property.
Common questions
How long is the power off?
Assume most of the working day. We can sequence around a critical item if you tell us in advance.
Do I need a new consumer unit just because mine is old?
No. Age alone is not a fault. What matters is whether the protection is adequate for the circuits present and the condition of the installation.
Why did my new board start tripping when the old one never did?
Because the new board provides RCD protection the old one did not, and it detects existing faults the old board simply passed. The fault was already there.
Will I get paperwork?
Yes, an Electrical Installation Certificate with the full schedule of test results, and the work notified as required.
Can it be done alongside an EICR?
Often yes. Where an EICR recommends a board upgrade, we price it in writing and you are free to have that work done by anyone you choose.