Probably time to get a new Honeywell controller for it, I have just been servicing mine as the blower motor had come unstuck, and also some water leak from the hot water circuit cause immense corrosion and galvanic action that needed thorough wire brush cleaqning and job done nicely with new hammerite paint. Motor got sorted out and free to turn, the water corrosion also caused the connectors deterioration beyon cleaning and repairis so out they went and a chop block did a geed job. Last time my Honewell unit went in it cost me about £100.00 fitted by a Corgi man. I don't touch the gas side of things, only the secondary electrica d evices such as blower motors, solinoids, diverter valves etc. Good luck.
Mike
April 2009