I have a heated towel rail in a flat in an old block. The rail has two valves at each side of the bottom. If I turn the small bolts fully clockwise the rail becomes cold and if I turn them anti clockwise the rail becomes warm. However, there both valces leak around the small bolt bit. Do I need to only turn one bolt? Do I need to turn them less or do I need to do something else to fix them from leaking?

Steve S, February 2009