Worcester Bosch
Worcester Bosch Expansion Vessel 8 Litre 87161425020
At a glance
- Part type: Expansion vessel
- Also known as 1018303, N0535-1
- This part is fitted to a gas appliance; installation must be carried out by a Gas Safe registered engineer.
£106.58
£88.82 ex. VAT · VAT at 20%
Same-day dispatch
Ordered by 4pm Mon–Fri, 10:30am Sat.
30-day returns
Unused, in original packaging.
What it is
The Worcester Bosch 87161425020 is an 8 litre expansion vessel for the manufacturer's RSF and Greenstar combi boiler ranges. It is mounted on the heating circuit and absorbs the change in water volume as the system heats up and cools down, keeping the circuit pressure within its working range. Inside the vessel a diaphragm separates the system water from a pre-charged air cushion, so the air side can compress and expand without the water side losing pressure.
Signs this part needs replacing
- Boiler pressure climbs when the heating runs and falls back once the system cools
- System pressure drops repeatedly and needs regular topping up
- Water discharging from the pressure relief valve
- Water or corrosion staining around the vessel connection or the vessel body
- High pressure reading on the gauge with the boiler cold
Before you order
- Check the GC number or the appliance data plate to confirm the exact model before ordering
- The previous number for this part is ZMMIS118
- This part is fitted to a gas appliance; installation must be carried out by a Gas Safe registered engineer.
Mechanical
| Part type | Expansion Vessel |
|---|
Compliance
| Manufacturer part number (MPN) | 87161425020 |
|---|---|
| GC number | E01-603 |
| Barcode / EAN | 4010009727897 |
| GPC classification | Household Boilers/Furnaces/Tank Water Heaters Replacement Parts/Accessories |
| Alternative numbers | WB87161425020, ZMMIS118, 1018303, N0535-1 |
| Previous numbers | ZMMIS118 |
| Make | Model / assembly | Reference | Years | Fitment |
|---|---|---|---|---|
| WORCESTER 24i RSF COMBI NG (NOV 2004) | 47-311-37 | 47-311-37 | — | — |
| WORCESTER 24i RSF COMBI NG (SEP 2001) | 47-311-37 | 47-311-37 | — | — |
| WORCESTER 28i RSF NG | 47-311-54 | 47-311-54 | — | — |
| WORCESTER GREENSTAR 24 FSN-GB COMBI NG | 47-406-32 | 47-406-32 | — | — |
| WORCESTER GREENSTAR 28 FSN-GB COMBI NG | 47-406-33 | 47-406-33 | — | — |
| WORCESTER WORCESTER 24I RSF NATURAL GAS | — | — | — | |
| WORCESTER WORCESTER 28i RSF NATURAL GAS | — | — | — |
Documents & drawings
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