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Hamworthy Expansion Relief Valve 531905003

Hamworthy

Hamworthy Expansion Relief Valve 531905003

Hamworthy 531905003 expansion relief valve with a 3/4" BSP inlet, rated at 5 bar, for Dorcester water heaters and Hamworthy boilers.

At a glance

  • Also known as 2061404
Manufacturer part no.
531905003
Showing prices

£103.24

£86.03 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 Hamworthy 531905003 is a 3/4" BSP inlet expansion relief valve rated at 5 bar. It is fitted to Hamworthy boilers and Dorcester water heaters, where it relieves excess pressure from the expansion vessel circuit. When system pressure reaches the valve's set point, it opens and discharges through the outlet.

Signs this part needs replacing

  • Water discharging from the valve outlet when the system is cold
  • System pressure climbing above the normal cold-fill reading as the boiler heats
  • The valve fails to reseat after operating, leaving a continuous drip
  • Scale or debris in the valve seat preventing it from sealing
  • Pressure gauge readings that keep rising towards the 5 bar setting

Before you order

  • Confirm the inlet connection on your appliance is 3/4" BSP
  • Confirm the required relief pressure for the appliance is 5 bar
  • Check your model against the fit list above
  • Check the expansion vessel charge pressure and system fill pressure before fitting

Not sure which part?

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