Weep hole

Snowmelt

One of my friends asked me about weep hole in a radiator shut off valve. The only answer I had was so the zone doesn’t freeze and has just enough flow of hot water not to freeze. So my question is does all radiator shut off valves have weep holes ?
While on the subject, same friend is going to install a Weil McLain water boiler, in the directions the flow check valves where on supply and return? I told him that’s like wearing suspenders and a belt.
Thanks in advance guys

mattmia2

Depending on the piping arrangement flow checks may be necessary on the supply and return, you can get gravity circulation within the pipe on the side without the flow check in some situations.

PC7060

Old school hot water hand crank valves have small 1/4” hole to allow flow even when closed to reduce risk of freezing lines.  That’s how you can tell a steam valve, close fully with no hole. 

hot_rod

Snowmelt said:

One of my friends asked me about weep hole in a radiator shut off valve. The only answer I had was so the zone doesn’t freeze and has just enough flow of hot water not to freeze. So my question is does all radiator shut off valves have weep holes ? While on the subject, same friend is going to install a Weil McLain water boiler, in the directions the flow check valves where on supply and return? I told him that’s like wearing suspenders and a belt. Thanks in advance guys

Often there is either a zone valve, of a circ in one end of the zone, so really only one check is needed

If you  have a single pump systems with zone valves in the returns, check in the circulator, you are covered also.