When you’re choosing light bulbs, start with the fitting, the output you need, and whether the lamp is on a dimmer. GU10, E27, E14 and bayonet light bulbs all do the same job, but the wrong cap or a non-dimmable lamp bulb is where the call-backs start. LED light bulbs are usually the first swap for most replacements. Filament or decorative versions make more sense where the fitting is on show and the look matters.
Integral LED GLS Dusk till Dawn Sensor - 5W 470lm ES (E27)
Integral LED 5W ES bulb with dusk till dawn sensor, 470lm warm white
Light Bulb GLS - 5W ES Warm White
5W GLS light bulb with ES cap, warm white
Sylvania Lynx-LE 2G11 55W 865 SL Compact Fluorescent Lamp - 10 Pack
55W 2G11 compact fluorescent lamp, pack of 10
Luceco LED Bulb - 5.5W E27 ES 470 Lumens 2700K
5.5W E27 LED bulb, 470 lumens, warm white, non-dimmable
Forum Large Decorative Vintage T80 Lamp - 6W 4000K
6W 4000K vintage T80 decorative lamp
Crompton Lamps LED GLS Thermal Plastic - 5.5W B22d Very Warm White Opal
5.5W LED GLS bulb, B22d, very warm white opal, frosted, indoor use only
Energizer Filament LED Cooker Hood Light Bulbs - SES / E14 2 Pack
Two Energizer E14 filament LED cooker hood bulbs in warm white
Crompton Lamps LED Candle Thermal Plastic - 5W B22D Cool White Opal Dimmable
5W dimmable LED candle bulb, BC-B22d, cool white, opal
Status G9 LED Capsule Light Bulbs - 2W Day White
2W G9 LED capsule bulb, day white 6500K, 200 lumens
GE B22 Spiral Bulb - 15W 950 Lumens 2700K
950 lumen B22 spiral bulb, 15W, warm white
Start with the space you’ve got and how the lamp will be used, then narrow the light bulbs from there. A tight fitting or shallow shade rules out some shapes straight away. A dimmer changes the choice again, because not every lamp bulb behaves well at low output. Most call-backs come from the wrong cap or a bulb that looks right on paper but sits awkwardly in the fitting. If you’re replacing like for like, keep the cap and size consistent first, then decide whether you want a standard LED, a dimmable option, or a more decorative finish.
For most jobs, you narrow light bulbs by format before anything else. LED light bulbs are the usual pick when you want lower running cost and less heat, but the lamp still has to suit the bulb, and any dimming gear needs checking.
Bayonet light bulbs still make sense when you’re swapping like for like and want the same cap back in without changing the holder. Screw light bulbs, including e27 light bulbs and e14 light bulbs, cover the same sort of replacement work. E27 suits larger general-purpose fittings. E14 is more common in smaller decorative lamps. GU10 light bulbs are the one you reach for when the fitting takes a mains spotlight lamp, though the wrong type is less forgiving once it’s in hand.
The first check is the fitting and the lamp body around it. That tells you if you’re buying a straight replacement or changing the look of the job.
After that, check whether it needs to dim cleanly and whether LED light bulbs make sense for the running cost. A cheap swap that flickers on a dimmer gets called back.
Shape matters too. A shallow shade or tight lantern usually rules out the bulkier options. Decorative lamp bulbs are picked more for the finish than the output.
If the job is moving away from lamps altogether, Downlights are the next call. If you only need the light to come on when someone’s there, Motion Sensors may be the better buy.
Once you’ve settled the bulb spec, the next call is usually the gear around it - the fitting, any trim or screen, and whether the lamp needs a matching control or sensor. That keeps a simple replacement from turning into a second visit.
A lot of call-backs come from mixing the wrong bulb with the wrong fitting, or leaving the control side unresolved. If the job includes downlights or a timed circuit, sort those parts with the light bulbs so you’re not back chasing compatibility after the fact.














