Purging air

ea42003 · October 3

hello

Would someone be able to guide me in clearing air from the system. Boiler turns on and heat

works on first floor but baseboard on second floor is not getting heat.

leonz · October 3

Please provide us with more pictures of your heating system and more pictures of the steel compression tank.

Your heating system uses an air management system not an air elimination system to create the point of no pressure change.

Is the water fill valve for your boiler shut off???

If not, it has to be shut off and you need to drain the excess water out of the steel compression tank if it is waterlogged which may be the reason your heating system is not heating the upper floor

A steel compression tank has a 1/3 to 1/2 air charge and the remainder of the volume in the steel compression tank has water in it to create the point of no pressure change.

You have a steel compression tank that has an air charge and a larger volume of water to create the point of no pressure change which permits the circulator to deliver hot water to your heating system.

Your heating system needs a great deal of work but lets get the poor heating issues fixed first.

Alan (California Radiant) Forbes · October 3

It looks like the return line has a ball valve and hose bibb for purging, but it may only flush the lower floor unless there is a valve to shut off flow to the lower baseboard. You may have to add a valve if one’s not there.

ea42003 · October 3

hot_rod · October 3

that small chrome air vent above the pump needs to be removed or capped off

With that type of expansion tank , you cannot have auto air vents, as @leonz explained. It can pull the air bubble from the tank and cause it to waterlog

The extra tapping on top if the boiler could have a purger, but it would pipe up to the tank to put purged air into the tank. Its called an air management system

leonz · October 3

Thank you for providing the additional images.

This is a big question for you; is the drain valve under the steel compression tank a DRAIN-O-TANK valve??

If it is, you can find out if your steel compression tank is flooded by slightly opening the drain valve.

BUT before you open the valve you need to shut the ball valve off that is connected to the opposite end of the steel compression tank to keep the water from the boiler and baseboard runs from draining back to the tank.

After that you can open the valve under the tank to see if water come out of it DO THIS ONLY IF THE VALVE IS A DRAIN-O-TANK VALVE.

I guess for right now I would open each of the valves slightly with a bucket under the drain one at a time to see if any air comes out of the system before you do anything else-DO THIS WHEN THE CIRCULATOR IS RUNNING.

If there is no air coming out of the valves it is not an air problem causing the lack of heat on the second floor.

The piping under the green circulator concerns me a great deal does the pipe under the circulator enter the concrete floor or does it run along the floor?? Please upload more images when you have time as we love to see detail in plumbing for heating systems.

Leon

leonz · October 3

As Bob has said that silver automatic air vent MUST BE removed. I am sorry I missed that at first.

The water cushion in the steel compression tank is gone and the excess water in the steel compression tank must be drained out of it to allow it to work properly and create the point of no pressure change.

It's better to drain the boiler and then crack the drain o tank valve in the steel compression tank to allow it to be filled with water to the right level. When there is nothing but water coming out of the drain-o-tank valve you need to shut it off and shut the water fill valve off.

Afte that you can restart the boiler.

neilc · October 3

which circ is the upstairs that's not heating? green or black?

can you hear or feel that it is trying to run? is it hot?

if you follow the pipes on the dead zone, do you have valving to isolate flow, same question on the working zone, you're looking for a way to stop/isolate flow to the working zone, then purge out the dead zone,

post a better picture of the dead zone circ, the pipes around it, and valves, all in one wide shot if you can,

EdTheHeaterMan · October 3

Agree with removing the automatic air vent from your system. That is a recipe for a waterlogged expansion tank that will need constant maintenance over the years. The DRAIN-O-TANK valve may not be the best idea. I believe that you can get the air scoop that is built into the boiler to do all the necessary air removal you need. The 3/4" tapping that is next to the supply pipe on that boiler is designed to remove air from the boiler. That opening is at the very top of the cast iron so any air that accumulates in the system will end up getting released there. The 1½” supply opening actually picks up the hot water about 1” lower in the cast iron tapping as illustrated here:

By connecting a ¾” pipe to that opening and installing with a gradual pitch up to the compression tank (expansion tank) any air that accumulates in the system will be vented to the tank. That is the exact opposite of a waterlogged tank. In order to ensure that the air in the tank will not dissolve into the water and leave the compression tank, I recommend an AirTrol ATF-12 to keep thermosyphoning from happening inside that pipe. Thermosyphoning is how a waterlogged tank can happen and the ATF-12 fitting stops that process

Using a DRAIN-O-TANK valve fitting is just a valve that makes draining a waterlogged tank easier to do. If you are going the the expense of a new part the requires draining the system on order to install it, you may as well put in the part that will eliminate the waterlogging in the first place.

Purging air

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