venting

ed_17

I have two larger cast iron radiators that would accept a second vent.  There is a threaded plug at the top that I cannot get out on each.  If I drilled out the the threaded plug would the pieces that are drilled out make a racket if they drop inside the radiator.  Second question, one of these radiators has a thermostatic valve on it, would adding a second vent interfere with the thermostatic vent or just make it shut off sooner?  Thanks, Ed

Big-Al_2

Not a Good Idea

1) If some chips fell inside the radiator, they wouldn't cause any trouble.



2) The vent tapping at the top of a radiator is for bleeding air from a hot water system.  Putting a steam/air vent up there would not be as effective as putting a second one lower on the radiator because the first steam to hit the radiator would tend to rise up and close it.



3) Adding a second vent would tend to override the thermostatic vent, because it might continue to vent air after the thermostatic one is closed.  Having it up at the top of the radiator might negate this somewhat, but if you have a thermostatic vent on the radiator to stop it from getting too hot, why would you want to vent if faster in the first place?

Motty

TRV

Adding a second vent to the rad with a TRV will make the TRV (almost) useless. The TRV stays closed unless it needs heat while the second aire vent is always open.