Zone valve Home › Forums › Public Forums › General Plumbing › Zone valve This topic has 1 reply, 2 voices, and was last updated 23 years, 3 months ago by Guest. Viewing 1 reply thread Author Posts 4 Oct 2001 at 1:27 am #275306 MasterPlumbersKeymaster In a hot water loop system,Does anyone know if there are any issues with installing a zone valve on the return line, if you can’t reach the supply line. 4 Oct 2001 at 1:14 pm #291662 GuestParticipant One problem would be that convection could allow the first radiator to heat even with the zone valve closed. Author Posts Viewing 1 reply thread You must be logged in to reply to this topic. Log In Username: Password: Keep me signed in Log In