Old radiant - how to bleed

[Octavian]

How to bleed this old radiator?
it doesn't work and the shutoff valve is leaking when open.

The home has a big loop of cast iron maybe 1.5 or 2 inch - house foot print is 40 by 30 feet with 8 of these radiators +1 small one in bathroom

Or pull all of them out and replace with new baseboard? Can new baseboard be connected into old iron pipe or needs new PEX run as home runs - into new valves?

 

[GoingQuiet]

Right in the middle, see that 7/16” round bleeder port that opens via the square drive radiator key?
If you don’t have a key, the easiest thing to do is go buy a similar radiator vent from the plumbing supply for like $4. Take the key out of the bag, consider throwing the new vent into your chrome plated brass recycling bucket. Use key, bleed radiator. I’ve never seen a key for sale without a vent.

I presume that each radiator has a regular tee and a Mono Flow tee off of the main heating pipe downstairs. Bleeding such a system works best with a procedure, such as to pick a clockwise direction around the house to bleed every radiator in order and then do it a second time. That process takes more time but ensures all air is out of the system. Repeat proceedure for the second floor if applicable. Goes fastest with a helper monitoring the pressure gauge and modulating the fast feed lever on the automatic water feeder to maintain 20-25psi for you to push the air out faster.

Can you tighten the leaking packing nut?
Might want to gently vacuum the top of that radiator before putting the covers on for the last time.

 

[Sponsor]

 

[Octavian]

Thank you, I didn't know there is a "radiator key" - I will get one.

 

[Fitter30]

That nut on the stem of the valve if thats where its leaking spay nut with penetrating oil pull nut off wrap teflon tape around shaft a few turns put nut back on if it bottoms out put a few.more turn of teflon. Bleed system turn boiler and pump off let sit off and few minutes crack open vent valve have a can or jar to catch the water and a rag. Turn pump back on let run a few minutes repeat.

 

[Octavian]

that nut had to be tighten - as is - and stopped leaking, maybe someone didn't have the right pipe wrench to get in there and decided to shut off.
this is a new house for me that I am trying to remodel for myself, from an old lady, she had no clue.
all radiators are this way and they are painted over with at least 5 coats of paint that is peeling, they will be replaced later.
the baseboards are cost effective, and I will replace in summer

 

[Fitter30]

Your radiator looks like its multi pass can pull the covers and have them sand blasted and primed. New fin tube might be at different dimensions for the piping. If you decide to upgrade the system do a heat load first old systems were oversized.

 

[Octavian]

yes, either 9 inch tall baseboards with pex to a manifold, then add minisplits for AC but it will get expensive quick and still end up having a weird ac-heating system.
or pull the entire thing out and just do a central furnace with heat and AC

The plan is to add an entire new floor on top in the summer.