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WORCESTER GREENSTAR JUNIOR 25Si & 30Si EXPANSION VESSEL 87161055450 87161064310
IN STOCK
FROM £64.99
Worcester Greenstar Junior 25Si & 30Si Expansion Vessel & PRV 87161055450 87161064310
Product Overview
The Worcester Greenstar Expansion Vessel and Pressure Relief Valve Kit is a replacement assembly designed for use in selected Worcester Bosch Greenstar heating systems.
The kit includes the 6-litre expansion vessel (Part Number: 87161055450) and the pressure relief valve (Part Number: 87161064310).
The expansion vessel accommodates the increase in water volume that occurs as the heating system warms up. Its internal diaphragm separates the system water from a pressurised air or gas chamber, helping to maintain stable system pressure during normal operation.
The pressure relief valve provides an additional safety function by releasing excess system pressure when it reaches the valve's specified operating limit.
This kit provides the two components required for applicable replacement and servicing work on compatible Worcester Greenstar appliances.
ℹ️ Product Condition Options:
This part may be available in New or Refurbished condition. Please check the available options from the dropdown menu.
Technical Insight & Common Failure Symptoms
The expansion vessel helps control pressure changes within a sealed central heating system by accommodating the expansion of water as it heats up.
Over time, the vessel's internal diaphragm can deteriorate or the air pre-charge can be lost. The pressure relief valve can also become worn or fail to seal correctly.
Typical symptoms associated with a faulty expansion vessel or pressure relief valve include:
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Boiler pressure repeatedly increasing when the heating system is operating
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Heating system pressure rising excessively as the water heats up
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Pressure dropping after the heating system cools down
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Water discharging from the pressure relief valve outlet
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Frequent need to repressurise the heating system
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Expansion vessel losing its air or gas pre-charge
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Pressure relief valve failing to close or seal correctly
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Boiler shutting down due to abnormal system pressure
Replacing the faulty expansion vessel and/or pressure relief valve with the correct components may help restore stable system pressure and reliable operation.
Technical Specifications
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Part Type: Expansion Vessel & Pressure Relief Valve Kit
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Expansion Vessel Part Number (MPN): 87161055450
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Pressure Relief Valve Part Number: 87161064310
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Expansion Vessel Capacity: 6 Litres
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Vessel Type: Diaphragm Expansion Vessel
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Application: Sealed central heating systems
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Boiler Range: Selected Worcester Greenstar appliances
Compatibility
This kit is designed for selected models within the Worcester Bosch Greenstar range, including:
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Greenstar 25Si
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Greenstar 25Si LPG
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Greenstar 30Si
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Greenstar 30Si LPG
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Selected Greenstar i System appliances
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Selected Greenstar i Junior appliances
The expansion vessel reference 87161055450 is listed for the Greenstar 25Si and 30Si models, as well as other selected Greenstar i System and Junior appliances. The associated pressure relief valve reference 87161064310 is identified as a Worcester Bosch PRV. Compatibility of the complete kit should be checked against the individual appliance parts diagram.
Please strictly verify the manufacturer part numbers 87161055450 and 87161064310 against your boiler's technical manual, exploded parts diagram, or existing components before ordering to guarantee correct fitment.
Safety Advice
The expansion vessel and pressure relief valve form part of the boiler's sealed hydraulic and pressure safety system.
Installation, replacement and servicing should only be carried out by a suitably qualified heating engineer in accordance with the manufacturer's instructions and applicable UK safety regulations.
Before carrying out any work, ensure the boiler and heating system are safely isolated and that the system has been brought to the appropriate pressure and temperature conditions.
Never obstruct, cap or disable the pressure relief valve discharge. Always check that the replacement components have the correct specifications for the appliance.
Compatibility data not available for this product.
Delivery
Free next day UK delivery is available on orders over £50.
Orders placed before 3 PM are usually dispatched the same working day.
Delivery times may vary for remote areas, Highlands, islands, and non-mainland UK destinations.
If you need urgent delivery help, please contact our customer service team before placing your order.
All Orders First 30 Days:
You can return or cancel your orders for any reason at any time within 30 days of receipt. After 30 days, we reserve the right to charge a restocking fee or refuse the return.
Parts must be returned in the same condition and packaging as received, or we may deduct a percentage of the cost of the part.
A full refund or exchange will be agreed once the item(s) have been received and inspected to ensure they are unused and in their original packaging where applicable.
If the part is returned as faulty and is found to be working upon inspection, postage costs will be deducted from the refund.
Faulty Items After 30 Days:
All items come with a 1 year HTS warranty from the date of purchase. Warranty means HTS will repair or replace the item.
Refunds:
Our returns team will process your refund after we receive and check your items. Please allow up to 15 days for your refund to be processed.
The refund will be made to the original payment method used to place the order.
Contact Us:
For any queries, email us at returns@heatingtradesupplies.com or call +44 01912633708.
Customer Services
National Boiler Spares Ltd
Tyne View Terrace
Wallsend
Tyne and Wear
NE28 6SG
