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.
Osram Dulux D 2-Pin - 10W 840 Cool White 4000K
Osram Dulux D 10W 2-pin compact fluorescent lamp, cool white 4000K
Status LED Golf Bulb - 5.5W Warm White B22
5.5W LED golf bulb, warm white, B22 bayonet cap.
Crompton Lamps LED GLS - B22d 7.5W 2700K
Dimmable 7.5W LED GLS bulb, BC B22 cap, 2700K warm white
L.E.T. FCT5 2D 4-Pin Circle CFL Fluorescent Bulb - 22W 830
22W 2D 4-pin CFL bulb with warm white light
Crompton LED GLS BC B22 - 2700K 8.5W
LED GLS BC B22 lamp, 8.5W, 2700K warm white.
Integral LED GLS Lamp - 4.8W 2700K 470lm B22 Frosted Non-dimmable
4.8W LED GLS bulb, 470 lumens warm white, frosted, B22 cap, non-dimmable
Status LED 2D Lamp - 12W 2 Pin Warm White
LED 2D replacement lamp, 12W warm white, GR8 2-pin, 1400 lumens, non-dimmable.
GE LED Energy Smart E27 Bulb - 11W 810 Lumens 2700K
LED bulb with E27 cap, 810 lumens, warm white light
Crompton Lamps LED GLS Thermal Plastic Lamp - 11W 2700K 1055lm B22D Non dimmable
11W LED GLS lamp with B22d cap, 2700K warm white light, non-dimmable
Integral LED Lamp - 5W, 2700K, 470lm, GX53, Non-dimmable, Frosted
5W GX53 LED lamp, 2700K warm white, 470 lumens, non-dimmable frosted
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.














