Can you replace the expansion tank on my Navien boiler?

Yes. BoilerPart.ca supplies and professionally installs the genuine Navien expansion tank across Greater Vancouver. Our licensed technicians diagnose the fault, fit the correct OEM part, and test the system.

Do you sell the Navien expansion tank on its own?

No. Boiler parts are supplied and installed by our licensed technicians as part of a repair — we do not sell parts for individual or DIY purchase. We install the Navien expansion tank as part of a certified repair so it is fitted correctly, tested for safety, and keeps your Navien warranty valid.

How do I know my Navien expansion tank has failed?

Typical symptoms include: Pressure climbing then relief valve dripping; Pressure swings on each cycle; Boiler short-cycling; Air in radiators. On Navien boilers this can also show as E003 Ignition Failure or E012 Flame Loss. We confirm the diagnosis before any work.

Navien · Hydronic & Water

Navien Expansion Tank Replacement in Greater Vancouver

Genuine Navien expansion tank, supplied and professionally installed by Technical Safety BC–licensed gas fitters. Never sold for DIY.

Call (604) 359-1081 Request Service

The Expansion Tank on Your Navien Boiler

The expansion tank (expansion vessel) gives heated water room to expand, keeping system pressure stable. A waterlogged or failed tank causes pressure swings, repeated relief-valve discharge, and short-cycling.

On Navien systems — including models such as NCB-240E, NCB-210E, NHB-150 — a failing expansion tank often shows up as e003 ignition failure or related symptoms. We diagnose it precisely and install the correct genuine Navien part.

Typical Lifespan

5-10 years

Brand

Navien

Part Category

Hydronic & Water

Safety Warning

A relief valve that drips whenever the boiler heats up is usually a failed expansion tank, not a bad valve.

Signs of a Failing Navien Expansion Tank

Pressure climbing then relief valve dripping

Pressure swings on each cycle

Boiler short-cycling

Air in radiators

Tank feels solid/heavy

Parts Are Professionally Installed — Not Sold for DIY

For your safety and to keep your manufacturer warranty valid, BoilerPart.ca does not sell loose boiler parts over the counter or for self-installation. Under BC regulations, gas appliance components must be installed by a licensed gas fitter. Every part we source is genuine OEM and is professionally fitted, tested, and certified by our Technical Safety BC–licensed technicians as part of a complete repair or installation.