Worcester Bosch
Worcester Bosch Siphon Outlet 87186817120
Worcester Bosch siphon outlet, part 87186817120, for Greenstar condensate assemblies across 58 models.
At a glance
- Part type: Condensate assembly
- Also known as 1030875
- This part is fitted to a gas appliance; installation must be carried out by a Gas Safe registered engineer.
Showing prices
£3.37
£2.81 ex. VAT · VAT at 20%
Available to order · 3 working days
Available to order · 3 working days
Not certain it's the right part? The technical team verifies fitment before dispatch — no charge, and it stops a second trip.Call the technical teamSend a technical question
Same-day dispatch
Ordered by 4pm Mon–Fri, 10:30am Sat.
30-day returns
Unused, in original packaging.
What it is
The Worcester Bosch siphon outlet, part number 87186817120, is a condensate assembly component used in the condensate trap arrangement of Greenstar boilers. It forms the outlet side of the siphon, carrying condensate away from the heat exchanger while the trap maintains a water seal that keeps flue gases inside the combustion circuit. It is a Worcester Bosch spare listed under condensate traps and siphons.
Signs this part needs replacing
- Water pooling beneath the boiler or around the condensate trap
- Condensate overflowing from the trap rather than draining away
- Gurgling, bubbling or dripping noises from the condensate route
- Boiler locking out or failing to fire, particularly in cold weather
- Visible cracks, scale or sludge build-up on the outlet body
Before you order
- Check the GC number on the appliance data badge against the compatibility list to confirm the model
- Confirm the number on the existing component matches 87186817120 or 1030875
- Inspect the trap seals and gaskets while the assembly is apart and renew any that are hardened or split
- This part is fitted to a gas appliance; installation must be carried out by a Gas Safe registered engineer.
Mechanical
| Part type | Condensate Traps & Siphons |
|---|---|
| Length | 0.1mm |
| Width | 0.1mm |
| Depth | 0.1mm |
Compliance
| Manufacturer part number (MPN) | 87186817120 |
|---|---|
| GC number | J04-507 |
| Barcode / EAN | 4051516200640 |
| Commodity code | 8403 90 00 00 |
| GPC classification | Household Boilers/Furnaces/Tank Water Heaters Replacement Parts/Accessories |
| Alternative numbers | 1030875 |
| Make | Model / assembly | Reference | Years | Fitment |
|---|---|---|---|---|
| WORCESTER GREENSTAR 25SI COMPACT LPG | 47-406-51 | 47-406-51 | — | — |
| WORCESTER GREENSTAR 25SI COMPACT NG | 47-406-50 | 47-406-50 | — | — |
| WORCESTER GREENSTAR 25Si ErP COMPACT LPG | 47-407-74 | 47-407-74 | — | — |
| WORCESTER GREENSTAR 25Si ErP COMPACT NG | 47-406-73 | 47-406-73 | — | — |
| WORCESTER GREENSTAR 27I COMPACT SYSTEM LPG | 41-406-14 | 41-406-14 | — | — |
| WORCESTER GREENSTAR 27I COMPACT SYSTEM NG | 41-406-13 | 41-406-13 | — | — |
| WORCESTER GREENSTAR 27i ErP SYSTEM COMPACT LPG | 41-406-59 | 41-406-59 | — | — |
| WORCESTER GREENSTAR 27i ErP SYSTEM COMPACT NG | 41-406-58 | 41-406-58 | — | — |
| WORCESTER GREENSTAR 28 CDI COMPACT LPG | 47-406-45 | 47-406-45 | — | — |
| WORCESTER GREENSTAR 28 CDI COMPACT NG | 47-406-44 | 47-406-44 | — | — |
Showing 10 of 58 compatible appliances.
Fitment listings are a guide, not a guarantee. Plant-room assemblies get modified on site more often than not. Send us the GC number off the data badge and a photo of the existing valve and we will confirm before anything is dispatched.
Documents & drawings
Everything we hold for this part. Where a document exists but we don't hold it, the technical team will source it from the manufacturer — usually the same working day.
manual
WORCESTER appliance manual — GREENSTAR 25SI COMPACT LPG (GC 47-406-51), GREENSTAR 25SI COMPACT NG (GC 47-406-50), GREENSTAR 30 SI COMPACT LPG (GC 47-406-53), GREENSTAR 30 SI COMPACT NG (GC 47-406-52)
manualmanualWORCESTER appliance manual — GREENSTAR 25Si ErP COMPACT LPG (GC 47-407-74), GREENSTAR 25Si ErP COMPACT NG (GC 47-406-73), GREENSTAR 28Si ErP COMPACT, GREENSTAR 30Si ErP COMPACT LPG (GC 47-406-76), GREENSTAR 30Si ErP COMPACT NG (GC 47-406-75)
manualmanualWORCESTER appliance manual — GREENSTAR 27I COMPACT SYSTEM LPG (GC 41-406-14), GREENSTAR 27I COMPACT SYSTEM NG (GC 41-406-13), GREENSTAR 30I COMPACT SYSTEM LPG (GC 41-406-16), GREENSTAR 30I COMPACT SYSTEM NG (GC 41-406-15)
manualmanualWORCESTER appliance manual — GREENSTAR 27i ErP SYSTEM COMPACT LPG (GC 41-406-59), GREENSTAR 27i ErP SYSTEM COMPACT NG (GC 41-406-58), GREENSTAR 30i ErP SYSTEM COMPACT LPG (GC 41-406-61), GREENSTAR 30i ErP SYSTEM COMPACT NG (GC 41-406-60)
manualmanualWORCESTER appliance manual — GREENSTAR 28 CDI COMPACT LPG (GC 47-406-45), GREENSTAR 28 CDI COMPACT NG (GC 47-406-44)
manualmanualWORCESTER appliance manual — GREENSTAR 28CDi ErP COMPACT LPG (GC 47-406-78), GREENSTAR 28CDi ErP COMPACT NG (GC 47-406-77), GREENSTAR 32CDi ErP COMPACT LPG (GC 47-406-80), GREENSTAR 32CDi ErP COMPACT NG (GC 47-406-79), GREENSTAR 36CDi ErP COMPACT LPG (GC 47-406-82), GREENSTAR 36CDi ErP COMPACT NG (GC 47-406-81)
manualmanualWORCESTER appliance manual — GREENSTAR 32CDI COMPACT LPG (GC 47-406-47), GREENSTAR 32CDI COMPACT NG (GC 47-406-46), GREENSTAR 36CDI COMPACT LPG (GC 47-406-49), GREENSTAR 36CDI COMPACT NG (GC 47-406-48)
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