Seized fittings in cast iron radiator

Stephen_7

I have a steam radiator in good condition that I need to convert to hot water. I cannot seem to move (turn) the plug fitting on the bottom (or top for that matter) on the opposite side from the existing steam fitting so I can add the return water line to the radiator. How does one loosen this fitting (without breaking something)? My pipe wrench is fairly large but all I seem to do is chip the hex end on the plug when I try to turn the fitting.

Mike T., Swampeast MO

Have only done a few times, but it's usually a royal pain--particularly with old steam rads. Hot water rads seem a little easier.

Try heating the area around the plug with a torch--sometimes it helps. Be patient and get it nice and hot. After heating I once gave the plug itself a good dousing with automotive starting fluid (ether and VERY cold). Didn't crack the rad, but didn't crack the joint either and I'd already nearly rounded off the head...

I've borrowed a giant socket wrench and 5-sided socket from a diesel truck mechanic. Unfortunately, the casting is often fairly crude and socket either won't fit tightly or won't go on very far. Sometimes it works...if you try this first before you bugger it up with a pipe wrench.

Usually it's drill out the center and then VERY carefully grind or cut just up to the lands of the threads. Consider it therapy.

Unknown

It`s a \"****\"............

I don`t "relish" that job, but I`ve done-it. I usually wind-up cutting them out too! Good- Luck to you!!