I have a Capitol gas boiler...old bugger. 90000 btu, series # 5-11 with a bell & gossett pump and each room has its own regulator. Well some rooms are hot and others are cold. These valves are highly corroded and Im afraid cranking on them might do more harm than good. If these things do move which way allows more/less flow? My drunk plumber friend told me this would be an expensive part to replace and not to touch it....