Mixing Copper and Cast Iron Radiators Home › Forums › Public Forums › General Plumbing › Mixing Copper and Cast Iron Radiators This topic has 3 replies, 4 voices, and was last updated 22 years, 3 months ago by davetonk. Viewing 3 reply threads Author Posts 2 Oct 2002 at 2:58 pm #275820 wlebow I have heard that mixing copper and iron radiators in the same system is bad because of the heat transfer rates of the two materials. Can you tell me what the consequence of such a mix would be on the system ?Thanks Dave 2 Oct 2002 at 4:52 pm #292945 NickHydroParticipant Wen copr an cast ar onthe sam loope an the thermstate is in the copr room the cast room stayt cold wen the thermstate is in the cast room the copr room ovreheets 4 Oct 2002 at 1:51 pm #292946 MitchDavisParticipant You need to put a Dielectric union, you can find them at most supply stores. Watts/AB makes one. 4 Oct 2002 at 9:18 pm #292947 davetonkParticipant Thanks Nick and Mitch.. you have helped a lot… » This message has been edited by davetonk on 04 October 2002 Author Posts Viewing 3 reply threads You must be logged in to reply to this topic. Log In Username: Password: Keep me signed in Log In