Christmas light replacement bulbs and fuses, matched by base rather than by picture
A dead string is usually a fuse. A dead section is usually a bulb. Both are cheap to fix, and both go wrong if you buy the wrong base.
By Sawyer V. · Published
Check the fuse in the plug before you buy anything else. If the whole string is dark rather than part of it, that is almost always what failed, and the VEXUNGA kit is the most completely specified product on this page. For C9 bulbs, buy on color temperature: the SUNSGNE 25 pack at 2200 K matches older incandescent runs, the BORT 25 pack at 2700 K matches modern warm white LED. For mini strings, the bulb is not a C9 at all — it is a 2.5 V push-in, and the Mudder 100 pack is the one to own.
This site already covers how to find the fault: the testers are on Christmas light testers and the diagnosis order on half the string is out. This page is the other half of that job — what you actually buy once you know what failed.
Wreath & Watt earns a commission on qualifying purchases made through the Amazon links on this page. It costs you nothing and it does not change the order of the picks — here is exactly how we are funded.
Quick picks
| # | Product | Best for | Score | Price |
|---|---|---|---|---|
| 1 |  SUNSGNE C9 LED replacement bulbs, 25 pack, E17, 0.6 W, 2200 K25 pack, E17 base, 0.6 W, 2200 K | A C9 run where you want every figure published | 9.0/ 10 | $25.99Amazon #ad · Price as of October 10, 2026 · Disclosure |
| 2 |  VEXUNGA Christmas light fuse kit, 3 values, 75 pieces, 125 V2.5 A, 3 A and 5 A at 125 V, 3.6 x 10 mm, 75 pieces | The first thing to replace when a whole string is dead | 7.0/ 10 | $8.99Amazon #ad · Price as of October 10, 2026 · Disclosure |
| 3 |  BORT C9 LED replacement bulbs, 25 pack, E17, 2700 K25 pack, E17 base, 2700 K | Matching a modern warm white LED run | 7.5/ 10 | $15.99Amazon #ad · Price as of October 10, 2026 · Disclosure |
| 4 |  Mudder mini light replacement bulbs, 2.5 V, 100 pieces, clear2.5 V push-in bulbs, 100 pieces | Mini-light strings, where the bulb is not a C9 at all | 7.3/ 10 | |
| 5 |  Festive Living G50 shatterproof LED replacement bulbs, 25 packG50 globe, 25 pack, no published baseSkip this | Skip | 3.0/ 10 | $34.98Amazon #ad · Price as of October 10, 2026 · Disclosure |
Scores are our own weighting of published manufacturer specifications, explained in full on how we research. They are not test results. We have not tested these products.
The picks in full
#1 — A C9 run where you want every figure published
SUNSGNE C9 LED replacement bulbs, 25 pack, E17, 0.6 W, 2200 K
25 pack, E17 base, 0.6 W, 2200 K
9.0
/ 10
The pick. Three published figures where the field averages one, and the warmest color temperature here for matching an existing run.
Published specifications
- Bulb format
- C9
- Base
- E17 intermediate
- Count
- 25
- Watts per bulb
- 0.6 W
- Color temperature
- 2200 K
- Material
- Plastic, shatterproof
- Pack load
- 15 W per 25 bulbs (25 x 0.6 W — our arithmetic)
Our scoring
- Published specs
- 10 / 10
- Fitment clarity
- 10 / 10
- Count per pack
- 6 / 10
- Color match detail
- 10 / 10
Good
- The only pack on this page that publishes base, wattage and color temperature together, which are the three facts that decide whether a bulb fits, what it draws and whether it matches the run it is joining
- At 2200 K this is the warmest option here — the amber end of warm white, which is what matches older incandescent C9 runs rather than clashing with them
- Plastic rather than glass, which on a roofline is the difference between a dropped bulb and a dropped bulb plus a cleanup
Watch out
- 2200 K is noticeably warmer than the 2700 K pack below, so the two cannot be mixed in one visible run
- Twenty-five bulbs is one standard C9 stringer's worth — a long roofline needs several packs
- No published lumen figure, which nobody in this category publishes
#ad · Price as of October 10, 2026 · How we are funded
Specs from the Amazon listing (ASIN B0CDC9BV4Q), verified via the Creators API 2026-10-06.
#2 — The first thing to replace when a whole string is dead
VEXUNGA Christmas light fuse kit, 3 values, 75 pieces, 125 V
2.5 A, 3 A and 5 A at 125 V, 3.6 x 10 mm, 75 pieces
7.0
/ 10
The cheapest repair in Christmas lighting and the one most people never try. Pull the plug fuse before you buy a new string.
Published specifications
- Values
- 2.5 A, 3 A, 5 A
- Voltage
- 125 V
- Size
- 3.6 x 10 mm
- Count
- 75
- Type
- Mini glass, fast blow
- Stated fitment
- C7 and C9 string lights, plug fuses
Our scoring
- Published specs
- 10 / 10
- Fitment clarity
- 9 / 10
- Count per pack
- 9 / 10
- Color match detail
- 0 / 10
Good
- Publishes all three amp values, the voltage and the physical size, which together are the entire specification of a fuse — this is the most completely specified product on the page
- Three values covers the fuses actually fitted in Christmas light plugs, rather than a 20-value automotive assortment where most of the kit is useless
- When a whole string is dark rather than half of it, the fuse in the plug is the first thing to check and the cheapest thing to replace
Watch out
- Fuses blow for a reason: replacing one on a string that keeps blowing it is treating a symptom, and the reason is usually too many sets joined end to end
- 3.6 x 10 mm is the common size but not the only one — check the fuse you pull out against the kit before assuming it fits
- Glass fuses in a plug are fiddly in cold hands
#ad · Price as of October 10, 2026 · How we are funded
Specs from the Amazon listing (ASIN B0CFXQTN8Q), verified via the Creators API 2026-10-06.
#3 — Matching a modern warm white LED run
BORT C9 LED replacement bulbs, 25 pack, E17, 2700 K
25 pack, E17 base, 2700 K
7.5
/ 10
The right pack if your existing run is modern warm white LED. Buy on color temperature here, not on price.
Published specifications
- Bulb format
- C9
- Base
- E17
- Count
- 25
- Color temperature
- 2700 K
- Watts per bulb
- Not stated in the listing
- Material
- Not stated in the listing
Our scoring
- Published specs
- 6 / 10
- Fitment clarity
- 9 / 10
- Count per pack
- 6 / 10
- Color match detail
- 9 / 10
Good
- 2700 K is the color temperature most warm white LED Christmas sets ship at, so this is the pack that matches a modern run rather than an old incandescent one
- Publishes base and color temperature, which is enough to buy correctly
- Sits within a cent a bulb of the top pick, so the choice between the two is purely the color temperature
Watch out
- No published wattage, so the load a full roofline of them draws cannot be worked out before they arrive
- Does not state whether the bulbs are plastic or glass
- At 2700 K it will read cooler beside a 2200 K bulb, and a single mismatched bulb in a line is more visible than a dead one
#ad · Price as of October 10, 2026 · How we are funded
Specs from the Amazon listing (ASIN B08DQQ94WM), verified via the Creators API 2026-10-06.
#4 — Mini-light strings, where the bulb is not a C9 at all
Mudder mini light replacement bulbs, 2.5 V, 100 pieces, clear
2.5 V push-in bulbs, 100 pieces
7.3
/ 10
The pick for mini strings, and only for mini strings. Check the voltage printed on your string's tag before you order.
Published specifications
- Bulb format
- Mini, push-in
- Voltage
- 2.5 V
- Count
- 100
- Color
- Clear
- Base
- Push-in wedge (no screw base)
- Watts per bulb
- Not stated in the listing
Our scoring
- Published specs
- 7 / 10
- Fitment clarity
- 8 / 10
- Count per pack
- 10 / 10
- Color match detail
- 4 / 10
Good
- Publishes the voltage, which is the single thing that matters on a mini string — a 2.5 V bulb in a 3.5 V socket runs dim and a 3.5 V bulb in a 2.5 V socket burns out
- A hundred bulbs is several strings' worth, which is the right quantity for the one failure mode mini lights actually have
- Push-in bulbs need no tools, which is why a mini string is a cheaper repair than a C9 run
Watch out
- Does not fit a C9 or C7 socket — different format entirely, and buying the wrong one is the most common mistake in this category
- Clear only, so a multicolor string needs a colored pack instead
- No published wattage
Specs from the Amazon listing (ASIN B07YFBR3BZ), verified via the Creators API 2026-10-06.
#5 — skip this
Festive Living G50 shatterproof LED replacement bulbs, 25 pack
G50 globe, 25 pack, no published base
3.0
/ 10
Our skip. A replacement bulb is defined by its base, and this listing does not print one. Buy a bulb that tells you what it screws into.
Published specifications
- Bulb format
- G50 globe
- Count
- 25
- Color
- Warm white
- Material
- Shatterproof
- Base
- Not stated in the listing
- Color temperature
- Not stated in the listing
- Watts per bulb
- Not stated in the listing
Our scoring
- Published specs
- 2 / 10
- Fitment clarity
- 1 / 10
- Count per pack
- 6 / 10
- Color match detail
- 3 / 10
Good
- Shatterproof, 25 pieces, and it is in stock
Watch out
- Publishes no base, and the base is the entire compatibility question in a replacement bulb — without it there is no way to know whether it fits the socket you are holding
- G50 is a different bulb shape from C9, so even a correct base changes the look of a mixed run
- The highest price on this page while publishing the least
#ad · Price as of October 10, 2026 · How we are funded
Specs from the Amazon listing (ASIN B0G1V61YPJ), verified via the Creators API 2026-10-06.
How we ranked these
The base, or the voltage, first. On a replacement part, fitment is not one factor among several — a bulb that does not fit is worth nothing, however good it is. Then color temperature, because a single mismatched bulb in a line is more visible than a dead one. Then wattage, then count per pack.
| Part | Format | Base or voltage | Count | Watts | Color temp |
|---|---|---|---|---|---|
| SUNSGNE C9 | C9 bulb | E17 intermediate | 25 | 0.6 W | 2200 K |
| VEXUNGA fuse kit | Plug fuse | 125 V, 3.6 x 10 mm | 75 | 2.5 / 3 / 5 A | n/a |
| BORT C9 | C9 bulb | E17 | 25 | Not stated | 2700 K |
| Mudder mini bulbs | Mini push-in | 2.5 V | 100 | Not stated | Clear |
| Festive Living G50 | G50 globe | Not stated | 25 | Not stated | Not stated |
The fuse row carries amp values rather than watts, because that is what a fuse is rated in. Color temperature is only published by the two C9 packs.
Source: Manufacturer listings on Amazon.com, verified via the Creators API October 2026.
Start with the fuse
There are two failure patterns and they point at different parts. If part of a string is dark, a bulb or a socket in that section failed. If the whole string is dark, the power never got into it, and on a C7 or C9 set the usual reason is the fuse inside the plug — a glass cartridge behind a little sliding door on the male end.
Replacing it costs pennies. The VEXUNGA kit publishes all three amp values, the voltage and the physical size, which is the complete specification of a fuse, and it carries the three ratings actually fitted to Christmas light plugs rather than a twenty-value automotive assortment where most of the kit is useless.
Base, and the mistake this whole category exists around
A replacement bulb is defined by what it screws or pushes into, and the formats are not interchangeable. C9 bulbs use an E17 intermediate screw base. C7 bulbs use the smaller E12 candelabra base. Mini lights do not screw in at all — they are a push-in wedge with two wires folded up the sides, rated in volts rather than by a base name.
That is why the Mudder 2.5 V pack is on this page and is not an alternative to the C9 packs. It publishes the voltage, which is the one thing that matters on a mini string: a 2.5 V bulb in a 3.5 V socket runs dim, and a 3.5 V bulb in a 2.5 V socket burns out early. The voltage is printed on the tag near the plug of the string you are repairing. The full format explanation is on mini, C7, C9 or festoon.
Why the two C9 packs are both picks
A replacement bulb has to match the bulbs around it, and warm white is not one color. At 2200 K the light is amber — the color an old incandescent C9 run gives. At 2700 K it is noticeably whiter. Five hundred Kelvin is a visible difference in a line of bulbs on a gutter, and a single bulb of the wrong temperature stands out further than a dead socket.
So the choice is not quality. Match the run: 2200 K against an incandescent or warm-amber LED run, 2700 K against a modern warm white LED set. If you do not know, pull one working bulb and buy the pack whose photographs look like it, or re-bulb the whole visible run in one temperature. The same decision in a wider context is on warm white vs cool white, and the incandescent-to-LED comparison on LED vs incandescent.
What a pack of LED replacements actually draws
Only one bulb on this page publishes a wattage, and it is worth doing the arithmetic because the result is the argument for re-bulbing an old run rather than replacing it.
The arithmetic
- SUNSGNE C9: 0.6 W per bulb, published
- One 25-bulb pack: 25 x 0.6 = 15 W
- At 120 V: 15 / 120 = 0.125 A per 25 bulbs
- A 100-bulb roofline: 4 packs = 60 W = 0.5 A
A hundred LED C9 bulbs draw about half an amp. That is the whole reason re-bulbing an incandescent C9 run with LED bulbs changes what the circuit can carry — the socket count stays the same and the load collapses.
The circuit-level consequence, including how many runs a 15 A outdoor circuit will take, is worked out on how many amps, and the running cost on what Christmas lights cost to run.
When a repair stops being worth it
Bulbs and fuses are the cheap failures. Two others are not: a failed socket, where the contacts in the lamp holder have corroded, and a break in the stringer wire itself. Neither is fixed by a bulb, and on a retail-gauge set neither is economically worth repairing.
The dividing line is published wire gauge. A commercial 18 AWG SPT-1 run is worth re-bulbing and re-socketing for years; a 22 AWG retail set that has been stapled and iced for six seasons is not. That distinction is set out on commercial-grade or big-box, and the expected service life on how long Christmas lights last.
Why the G50 pack is the skip
The Festive Living G50 pack is shatterproof, which is a real virtue, and its listing publishes no base. On a replacement bulb that is the entire compatibility question: without it there is no way to know whether it fits the socket you are holding.
G50 is also a different bulb shape from C9 — a round globe rather than the faceted cone — so even a correct base changes the look of a mixed run. At the highest price on this page while publishing the least, it is the one to walk past.
Questions
›Why is my whole string of Christmas lights out?
Usually the fuse in the plug. On a C7 or C9 set there is a small sliding door on the male plug with one or two glass cartridge fuses behind it. If the entire string is dark rather than one section, replace that first — it costs pennies and is the commonest failure.
›What base do C9 Christmas light bulbs use?
E17, the intermediate screw base. C7 bulbs use the smaller E12 candelabra base, and mini lights do not screw in at all — they are push-in wedge bulbs rated in volts. Buying across those three formats is the commonest mistake in this category.
›What voltage are mini Christmas light bulbs?
Commonly 2.5 V or 3.5 V, and it is printed on the tag near the plug of your string. A 2.5 V bulb in a 3.5 V socket runs dim; a 3.5 V bulb in a 2.5 V socket burns out early. Check the tag before ordering.
›Can I put a higher-rated fuse in to stop it blowing?
No. The fuse rating is a property of the cord, not a setting. A fuse that blows repeatedly means the run is drawing more than the plug is rated for, and the fix is to split the run into fewer sets per circuit.
›How much power do LED C9 replacement bulbs use?
The one pack here that publishes a figure states 0.6 W per bulb, which is 15 W for a 25-bulb pack and about half an amp for a 100-bulb roofline at 120 V. That is the arithmetic behind re-bulbing an incandescent run rather than replacing it.
Sources
- SUNSGNE C9 LED replacement bulbs, 25 pack (ASIN B0CDC9BV4Q) — C9, E17 intermediate base, 0.6 W, 2200 K, plastic
- VEXUNGA Christmas light fuse kit, 75 pieces (ASIN B0CFXQTN8Q) — 2.5 A, 3 A and 5 A at 125 V, 3.6 x 10 mm, stated for C7 and C9
- BORT C9 LED replacement bulbs, 25 pack (ASIN B08DQQ94WM) — C9, E17 base, 2700 K; no wattage published
- Mudder mini replacement bulbs, 2.5 V, 100 pieces (ASIN B07YFBR3BZ) — 2.5 V push-in, clear
- Festive Living G50 LED replacement bulbs, 25 pack (ASIN B0G1V61YPJ) — G50 globe, shatterproof; no base published
- Load arithmetic — Pack wattage is 25 x the published 0.6 W; current is watts divided by 120 V. Both ours, from the one published wattage on the page.
We have not tested these products. Every figure above comes from a published manufacturer specification or from arithmetic shown on this page, and anything a maker does not publish is printed as unavailable rather than estimated. How that works, and what we will not claim, is set out on how we research.