Worcester Bosch
Worcester Bosch Expansion Vessel Adaptor 87186854910
Worcester Bosch expansion vessel adaptor connector, part 87186854910, for Greenstar gas boilers; GC number J04-456.
At a glance
- Part type: Adaptors & Connectors
- Also known as 1030983
- This part is fitted to a gas appliance; installation must be carried out by a Gas Safe registered engineer.
Showing prices
£6.68
£5.57 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 87186854910 is an expansion vessel adaptor connector used on Worcester Bosch gas boilers. It forms the connection between the expansion vessel and the appliance's hydraulic circuit, allowing the vessel to absorb changes in system water volume as the boiler heats and cools. The part sits within the Greenstar range of combi, system and compact models.
Signs this part needs replacing
- Water weeping or a visible drip at the expansion vessel connection
- Gradual loss of system pressure, with the filling loop used more often than usual
- Corrosion, scale or staining on the adaptor body or its threads
- Damp patches or mineral deposits around the vessel connection point
- Pressure that will not hold after the system has been refilled and bled
Before you order
- Check the GC number on the appliance data badge against the compatibility list below before ordering.
- The alternative number 1030983 may appear on older documentation for the same item.
- This part is fitted to a gas appliance; installation must be carried out by a Gas Safe registered engineer.
Mechanical
| Part type | Adaptors & Connectors |
|---|---|
| Length | 0.1mm |
| Width | 0.1mm |
| Depth | 0.1mm |
Compliance
| Manufacturer part number (MPN) | 87186854910 |
|---|---|
| GC number | J04-456 |
| Barcode / EAN | 4051516263492 |
| Commodity code | 7412 20 00 00 |
| GPC classification | Household Boilers/Furnaces/Tank Water Heaters Replacement Parts/Accessories |
| Alternative numbers | 1030983 |
| 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)
manualNo technical questions yet for this part.
Not sure which part?
Search by part number, product name or brand — our technical team confirms fitment before anything is dispatched.