Rather than having to drain & then bleed etc the system is it practical to replace only the top of of a thermostatically controlled radiator valve. The original (PEGLER Terrier) is probably 10 to 15 years old so it will be a different top. If the threaded metal colar & the plastic body are the same fit it should be OK shouldn't it?

David Irving, January 2008

NOT LIKELY AS THE INTERNAL MECHANISM WOULD NEED TO BE THE SAME

MIKE GASMAN, January 2008