Viessmann 7828646 Expansion Vessel CRI 8 + PRV 7837892

Description

Viessmann 7828646 Expansion Vessel CRI 8 + PRV 7837892

The Viessmann 7828646 Expansion Vessel CRI 8 is an original replacement designed to maintain stable system pressure in compatible Viessmann boilers.

This assembly includes the Pressure Relief Valve (PRV) 7837892, ensuring correct pressure protection and safe boiler operation.

The expansion vessel absorbs the natural expansion of water during heating cycles. If the diaphragm fails, you may experience:

• Boiler losing pressure regularly

• Pressure rising above 3 bar

• Water discharging from the safety valve

• Frequent need to repressurise

Replacing the expansion vessel restores correct system balance and prevents further pressure-related faults.

Viessmann 100-W WB1B Series

• 100-W WB1B 26kW Combi (Serial No. 7373061) – 47-819-12 (7373061)

• 100-W WB1B 26kW System (Serial No. 7373060) – 41-819-18 (7373060)

• 100-W WB1B 30kW Combi (Serial No. 7373063) – 47-819-13 (7373063)

• 100-W WB1B 30kW System (Serial No. 7373062) – 41-819-19 (7373062)

• 100-W WB1B 35kW Combi (Serial No. 7373065) – 47-819-14 (7373065)

• 100-W WB1B 35kW System (Serial No. 7373064) – 41-819-20 (7373064)

• If you’re looking for a Viessmann Spares  follow the link provided.

  Delivery and Return

  Place orders before 1 PM for same-day dispatch via reliable couriers. Choose from standard or next-day delivery options. Returns are accepted within 30 days if the part is unused and in original packaging. Always use a Gas Safe registered engineer for installation and warranty compliance.