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Worcester Bosch By-Pass Valve Assembly 87161064340

Worcester Bosch

Worcester Bosch By-Pass Valve Assembly 87161064340

Worcester Bosch by-pass valve assembly, part 87161064340, for Greenstar i and i ErP system and combi boilers; regulates flow through the heating circuit.

At a glance

  • Part type: By-pass valve assembly
  • Also known as 1014905
  • This part is fitted to a gas appliance; installation must be carried out by a Gas Safe registered engineer.
Manufacturer part no.
87161064340
GC number
H02-532
Showing prices

£17.04

£14.20 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 by-pass valve assembly is a Worcester Bosch spare that regulates the flow of water through the primary heating circuit, allowing a controlled path around the boiler when system demand falls. It sits within the hydraulic section of the appliance and helps keep the heat exchanger working within its design flow conditions. This version is supplied under Worcester Bosch part number 87161064340 and is listed against the Greenstar i and i ErP families.

Signs this part needs replacing

  • The boiler short-cycles on the heating circuit, firing and shutting down more often than the demand requires.
  • Flow and return temperatures climb quickly, or the appliance reaches its overheat limit during low-demand periods.
  • Radiators heat when only hot water has been called for, or the heating circuit stays warm after the demand has ended.
  • Audible water noise or vibration through the boiler and nearby pipework when the system is running.
  • Water weeping or staining around the hydraulic block where the valve body sits.

Before you order

  • Check the GC number on the appliance data badge against the list above, as the same model name can be built to more than one specification.
  • Confirm the part number 87161064340 or the alternative number 1014905 against the old component before ordering.
  • Inspect the sealing washers and O-rings on the hydraulic block and renew them if they are compressed or perished.
  • This part is fitted to a gas appliance; installation must be carried out by a Gas Safe registered engineer.

Not sure which part?

Search by part number, product name or brand — our technical team confirms fitment before anything is dispatched.