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.
Status LED Golf Bulb BC - Warm white 4W B22
4W filament LED golf bulb, B22 bayonet cap, warm white light.
Crompton Lamps 15W Pygmy B22 Dimmable - Amber
15W amber decorative pygmy bulb with B22 base, dimmable, IP65 rated
Linear Tungsten Halogen Tube - 117mm 160W/200W
117mm linear tungsten halogen tube bulb, 160W
Crompton Sign Lamp - 15W Clear, 2800K, 105lm, B15D
15W clear sign lamp, 2800K warm white, B15D cap
Goodwin GU10 Standard & Dimmable Coloured LED Light - 4W Red
Dimmable 4W GU10 red LED light
V-TAC VT-249 6W GU10 Ripple Plastic Spotlight with Samsung Chip VT-2002 - 4000K,…
6W GU10 LED spotlight, 4000K cool white, 10° beam, Samsung chip
Kosnic Candle 4.9W SBC B15 2700K
4.9W LED candle bulb SBC B15 2700K, saves 90% energy, 15,000hrs
V-TAC R39 Reflector Spot Light - 3W, 250lm, 6400K
3W LED reflector bulb, E14, 250lm, 6400K, IP20
Philips Master PL-S - 7W/840 4Pin 2G7 4000K Cool White
Philips Master PL-S 7W 2G7 compact fluorescent cool white lamp
Netlighting LED Filament GLS Lamp - 8.5W 2700K 1055lm B22 Dimmable Frosted
8.5W LED filament GLS lamp, 2700K, 1055lm, B22, 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.














