Need help purging air from system

Pipes5780

I have trapped air in my boiler system and cannot understand how to remove it. I have no isolation valves, and the only purge valves I have are on the supply side just before the zone valves.

To describe the setup, boiler I have a hy-vent and a pressure relief valve. On the supply side I have an expansion tank and then out of the boiler it splits into 3 zones. Each zone has a purge valve and then the Taco zone valve. On the return, all 3 zones are joined together and also merged with a line from the home water line with a pressure reducing valve. Following that the return feed runs directly into the circulator pump. There is an additional purge valve under the circulator just before it enters the boiler.

Beyond that there are no isolation valves at all on the system and no additional purge valves.

Andy help would be appreciated!

EdTheHeaterMan

Does the circulator have isolation Flanges? those are flanges with valves built in. Sometimes you need a screwdriver to close the valve. Sounds like you need to purge the air backwards, Can you take a picture of the boiler with the pipes from floor to ceiling and post it here?

Pipes5780

Pipes5780

Here is the circulator, no isolation flanges.

EdTheHeaterMan

Looks like you are missing a valve

Since the air was removed in the past, there must be another way to remove the air. What do your radiators look like?

Pipes5780

All the same, simple baseboards with no control valves or air valves.

EdTheHeaterMan

How are you at soldering? Can you add 3 ball valves at this location? Then you can use the fast fill feature on the autofeed to increase the pressure to the return side and then purge in reverse by opening one zone valve at a time.

EdTheHeaterMan

If you prefer no soldering, you can twist the pipes off with a pipe wrench. This Blue section of pipe can be removed by disconnecting the flange at the circulator and twisting the pipe that drops to the circulator pump. Then you can add a valve here with 2 short pieces of pipe. Then reassemble the pipes to the circulator pump and then you will have what you need to purge the system.

hot_rod

Moving the expansion tank connection would help, and adding a backflow device. All that could be done to the left of the union on the fill valve piping

An air purger would be nice also, but not so easy to add.

I’d pull out the drain valves and press in 3 of these, no soldering required.

EdTheHeaterMan

hot_rod said:

Moving the expansion tank connection would help, and adding a backflow device. All that could be done to the left of the union on the fill valve piping

An air purger would be nice also, but not so easy to add.

I’d pull out the drain valves and press in 3 of these, no soldering required.

If you dont have a Propress® tool you can rent one form HD or Lowes