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Halstead Diverter Valve Diaphragm 851130

Halstead

Halstead Diverter Valve Diaphragm 851130

Diverter valve diaphragm for Halstead Quattro, Trio and Wickes combi boilers.

At a glance

  • Part type: diverter valve diaphragm
  • Also known as 1293750
Manufacturer part no.
851130
Showing prices

£124.68

£103.90 ex. VAT · VAT at 20%

Available to order · 1 working day
Available to order · 1 working day
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 Halstead 851130 is a diverter valve diaphragm used in Halstead gas boilers. It sits inside the diverter valve assembly and moves under pressure to switch the boiler between domestic hot water and central heating operation. A split or hardened diaphragm stops the valve from changing over correctly.

Signs this part needs replacing

  • Hot water runs cold or only lukewarm while the boiler fires for heating
  • The boiler does not respond when a hot tap is opened
  • Heating and hot water operate at the same time when only one is called for
  • The diaphragm is visibly split, stretched or hardened when the valve is opened
  • Water weeping from the diverter valve body around the diaphragm housing

Before you order

  • Confirm the appliance model and GC number against the fit list above
  • Check the existing part number on the diaphragm or valve assembly matches 851130
  • Inspect the valve body and pushrod for wear, as a damaged diaphragm often accompanies other faults
  • Confirm whether the diaphragm alone is required or the complete diverter valve assembly

Not sure which part?

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