I want to replace my heating control timer (Randall 103) with a Honeywell RF Chronotherm. Is this possible?

Does not appear that you can, as the honeywell RF Chronotherm is a low voltage thermostat, and the timer is line voltage.

See specs for each below. If these are not correct, then provide the actual, accurate part numbers of each.

http://kivar.com.ua/files/honeywell/...F/CM61RFug.pdf

http://danfoss-randall.co.uk/PCMPDF/7479v04_2.pdf