Honeywell Gas valve VK8525MR1501U

The Honeywell VK8525MR1501U is a gas valve designed for use in Protherm RYS, LEOPARD, and TIGR boilers. It is an OEM equivalent to part number 0020035638. This valve shuts off and meters the gas supply to the burner, opening on command from the burner control and only when the gas pressure switch permits. In premix boilers, it connects pneumatically to the fan for gas/air ratio control.

When selecting a replacement gas valve of this type, confirm the connection size (typically Rp 1/2" to 2" or flanged), coil voltage (common options include 230 V or 24 V AC/DC), and function type (single or double solenoid, slow-opening, servo-regulated, or multiblock with filter and regulator). Check the valve body orientation and flow direction to match the existing installation. Ensure the gas supply is isolated before work.

Typical failures include coil burnout, leaking valve seat, drifting outlet pressure, or a seized servo regulator. Symptoms may include the burner failing to ignite, irregular flame, or the boiler shutting down due to gas pressure issues. Check the coil resistance and valve seat for leaks, and verify outlet pressure against specifications.