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Radiator Flow Direction

Timco Member Posts: 3,026
Air test the rad to 30#. The hotter pipe after it has been running a while is the supply. The rad does not care, you can put the valve on either side.

Just a guy running some pipes.


  • Andy Stern
    Andy Stern Member Posts: 10
    Radiator Flow Direction

    Hello... Got a 3 story gavity system that was converted to closed system (and pump). Third floor HAD a large rad but the previous owner had it removed and a 36" bypass line was installed with a union and some ells. He also had a large rad moved to the 3rd floor but never hooked it up. MUST HAVE BEEN QUITE A MOVING EXPERIENCE. I'd like to install it when I can find the fittings and a valve, but I'd like to know how to tell which way the flow is going though the short bypass so I know which end to install the valve.... or does it matter. ALSO... I'd like to pressure test the rad first. What pressure should I test it to??? I think the boiler gauge reads 18 PSI cold (in the basement), but at the 3rd floor it would be it's minimum ... Thanks all.
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