O Ring Toby DVR Metering Stem

O Ring for the metering stem in the TOBY oil control valves which are fitted to the Harmony, Stanford, Oxford oil stoves and the A80 and B80 Nestor Martin Hearth oil stoves.

This may need to be replaced if the metering stem becomes stuck down regularly as it could be out of shape. If the valve leaks-by into the burner pot then the O ring may be split and will need replaceing.