In fairness to all, we don't discuss pricing on the Wall. Thanks for your cooperation.
Has anyone used the Taco X-Pump Block?
but never with steam, so can't answer for your exact application. Worked great for the small radiant, and one s/m I used them for.
The 510 tekmar is a great choise in m opinion. We use a lot fo Tekmar, but usually complete controls, injection pump mixing, etc., and a lot of TN4 stuff.
The Taco control on the mixing block is actually something Tekmar makes for them, and takes care of the mixing, outdoor reset, etc, and the 510 and 079 sensor should match up great.