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Viessmann Expansion Vessel 12L 7831501

Viessmann

Viessmann Expansion Vessel 12L 7831501

Viessmann 12 litre expansion vessel, part 7831501, for Vitodens 222-F and 242-F gas boilers.

At a glance

  • Also known as 2321110
Manufacturer part no.
7831501
Showing prices

£203.44

£169.53 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 Viessmann 7831501 is a 12 litre expansion vessel used in Vitodens gas boilers. It absorbs the volume change of the system water as it heats and cools, holding the sealed heating circuit at a stable pressure. This vessel is listed for the Vitodens 222-F and 242-F appliance families.

Signs this part needs replacing

  • System pressure falls repeatedly and needs regular topping up.
  • The pressure gauge reads high when cold and rises sharply as the boiler heats.
  • Water or moisture appears at the vessel's air valve when the schrader valve is depressed.
  • The boiler locks out or shows a low pressure fault soon after the system is filled.
  • The pressure relief valve discharges during normal heating cycles.

Before you order

  • Confirm the appliance model and serial number against the fit list above.
  • Check the existing vessel's stated capacity to ensure a 12 litre unit is correct for the installation.
  • Verify the system volume and static head suit the vessel charge pressure for the property.
  • Ensure the replacement vessel can be accessed for fitting without disturbing other components.

Not sure which part?

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