What is this?
When a newly installed light fitting flickers immediately, the issue is almost always related to the installation itself — a loose connection made during fitting, an incompatible bulb or transformer, or a wiring error. This is a medium-risk situation because a poor connection made during installation can deteriorate quickly.
Common causes
- Loose wire connection made during installation at the ceiling rose or junction box
- Incompatible transformer or LED driver in the new fitting
- Wrong bulb type for the fitting (e.g., non-dimmable bulb on a dimmer circuit)
- Wiring error — live and neutral crossed, or earth not connected properly
- Damaged cable insulation caused during installation
- Existing dimmer switch not compatible with the new fitting
Is it dangerous?
A loose connection on a new fitting is potentially dangerous because it can overheat quickly under load. If the fitting was installed by an unqualified person, the risk is higher. If the fitting buzzes, feels hot, or produces a burning smell, turn it off at the switch and do not use it until an electrician has checked it.
Can I fix it myself?
If you installed the fitting yourself, turn off the power at the consumer unit and double-check all connections are tight and correctly terminated. Make sure the bulb is the correct type for the fitting and is dimmable if you have a dimmer switch. If you are not confident with electrical work, do not attempt to re-open the fitting yourself.
When to call an electrician
Call an electrician if the fitting was installed by someone else and flickers from the start, if you are not confident checking your own work, if the fitting buzzes or gets hot, or if you have checked the connections and the problem persists. Under Part P of the Building Regulations, some lighting work requires notification to Building Control.
What will an electrician do?
Inspect the new fitting and all connections made during installation
Check the wiring is correctly terminated (live, neutral, earth, and switched live)
Test the circuit for polarity and earth continuity
Replace any incompatible transformers or drivers
Assess dimmer switch compatibility and replace if needed
Issue a Minor Electrical Works Certificate for the installation
Typical cost
£60 – £180
Rectifying a poor connection is quick and inexpensive. If the fitting itself is incompatible and needs replacing, the cost of the new fitting is additional.
