Viessmann Boiler: Leaking water

Water around a Viessmann boiler can be a discharging pressure-relief valve (overpressure), a blocked or split condensate line, or a failing seal, fitting or heat exchanger. Water on live electrics or a hot heat exchanger is a safety issue.

Water around a Viessmann boiler can be a discharging pressure-relief valve (overpressure), a blocked or split condensate line, or a failing seal, fitting or heat exchanger. Water on live electrics or a hot heat exchanger is a safety issue. On Viessmann boilers, this is linked to 2 fault codes (F22, F23). Below are the likely causes, the safe checks you can make, and exactly what our licensed BC gas technicians do — because boiler repair in British Columbia is licensed gas work, not a DIY job.

Boiler repair is licensed gas work in BC. The checks below are the safe limit of DIY. Do not open the boiler or work on gas, combustion or safety controls — read the fault code, reset at most once, and call a licensed technician if it returns.

What you might notice

  • No or weak heat
  • Overheat or flow faults under load
  • Pump running but rooms stay cold

Safe checks you can make first

These are the only steps a homeowner should take. If they don’t resolve it, stop — the rest is licensed gas work.

  • 1Identify where the water comes from — top, bottom, condensate pipe, or a fitting
  • 2Check pressure: above ~30 psi suggests an expansion-tank / PRV fault
  • 3Place a container to catch water and protect the floor
  • 4Always call — do not run a leaking boiler near electrical components

Related Viessmann fault codes

These Viessmann codes are commonly behind “leaking water”. Tap any code for its full meaning, causes and fix.

What our licensed technicians do

  • Test circulator-pump operation and speed
  • Purge trapped air and check for air-bound zones
  • Inspect zone/mixing valves and strainers for blockage
  • Confirm correct flow rate and stable temperatures

Viessmann leaking water — FAQ

Why is my Viessmann boiler leaking water?

Water around a Viessmann boiler can be a discharging pressure-relief valve (overpressure), a blocked or split condensate line, or a failing seal, fitting or heat exchanger. Water on live electrics or a hot heat exchanger is a safety issue. The related Viessmann fault codes are F22, F23. A licensed technician confirms the true root cause with the right instruments before any repair.

Is it safe to keep resetting my Viessmann boiler when it shows "leaking water"?

Reset it at most once. If "leaking water" returns, the boiler is telling you there is a real fault that needs diagnosing — continuing to reset it can make things worse. Call GasBoilers.ca at 604-359-1081 and a licensed technician will find the cause.

Can you repair a Viessmann boiler with this problem in Greater Vancouver?

Yes. Our Red Seal–certified, TSBC gas-licensed technicians diagnose and repair Viessmann Vitodens 100-W, 200-W and 222-F series across Vancouver, Burnaby, Surrey, Richmond, the Tri-Cities and the rest of Greater Vancouver. Same-day appointments are often available — call 604-359-1081.

Viessmann boiler leaking water? We can help today.

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