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.
GE LED Filament E14 Bulb - 4W 470 Lumens 2700K
4W LED filament E14 bulb, 470 lumens, 2700K warm white
Goodwin Classic ST64 E27 LED Lamp - Clear 300° 6.5W/60W 806lm Dimmable RA80 2700…
Dimmable clear ST64 LED lamp 806lm warm white 2700K E27 6.5W
Integral LED Classic MR16 GU5.3 Light Bulb - 380lm 2.7W 4000K Non-Dimmable 3 Pac…
2.7W LED MR16 GU5.3 bulb, 380lm cool white 4000K, non-dimmable, 3 pack
Goodwin Classic Mini Globe LED Lamp - B22D Clear 300° 4W/40W 470lm Dimmable Ra80…
4W dimmable LED globe lamp, 470lm, 2700K, B22d
Bell Halogen Pygmy Bulb - 15W BC/B22 Very Warm White
15W halogen pygmy bulb with BC/B22 bayonet cap, very warm white
Wessex LED Frosted Mini Globe Bulb Lamps - 1.8W ES Warm White 250lm 4 Pack
Pack of four 1.8W LED frosted mini globe bulbs, 250lm warm white, ES cap
Crompton Lamps LED GU10 Bulbs - 4W Cool White 35° Dimmable 5 Pack (50W Equivalen…
4W LED GU10 cool white dimmable bulbs, 5-pack, 50W equivalent
Knightsbridge LED Corn Lamp - 54W, 4000K, 6870lm, E40, Non dimmable
54W LED corn lamp delivering 6870 lumens, 4000K, E40 base, non-dimmable.
Crompton Lamps LED Det Tubular - 284mm 6W Cool white opal (40W Eqv) 5 Pack
6W LED DET tubular bulb, 284mm, cool white opal, 5 pack
L.E.T. 2D 4-Pin Square CFL Fluorescent Bulb - 38W 840
38W 2D square CFL fluorescent bulb, 4000K cool white, GR10q base
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.














