Honeywell Gas valve VK8515MR4522U

The Honeywell VK8515MR4522U is a gas valve designed for use in Vaillant turboTEC Pro/Plus and other specified boiler models. It functions as a safety and metering component, shutting off gas when the burner is off and opening it when permitted by the burner control and gas pressure switch. This valve is part of the Honeywell brand and falls under the category of gas valves. Its SKU is VK8515MR4522U, and it is intended for the listed Vaillant boiler models.

When selecting a replacement gas valve of this type, verify the connection size, coil voltage, and required functions such as single or double solenoid action, slow-opening characteristics, or servo-regulated flow. The valve must match the original installation's brand and series designations. The coil may be replaceable separately, so check if the existing coil can be reused. Ensure the valve's mounting form and dimensions align with the boiler's specifications before ordering.

Common failures for gas valves of this kind include coil burnout, leakage past the valve seat, drifting outlet pressure, and a seized servo regulator. Symptoms may include the burner failing to ignite, irregular flame, or gas odor. Check the coil continuity, valve seat integrity, and outlet pressure regulation when diagnosing issues.