gtmtnbiker
New Member
I will be starting a project to add a 3rd zone to my boiler. The plan is to split off the family room from the first floor zone to be a separate zone. It should have been a separate zone when the addition was built 30-40 years ago. The first floor is serviced by 1†pipe and is split into 2 loops. One loop is for the family room. The other loop is for the rest of the first floor (dining room, hallway, kitchen, and family room). The family room is at the very end of the loop. It’s also on the north side of the house and has an unheated basement. These factors make the room 3-4 degrees cooler than the rest of the house.
The question I have concerns draining & purging the boiler. In the first step of the project, I will be adding onto the supply manifold. I plan to shut the isolation valves (4) on the supply and return sides. I will also isolate the boiler water feed. I’ll open the boiler drain to drain water from the boiler and manifolds below the isolation valves. How does air get into the system to break the vacuum? Does one have to open the valve on top of the automatic air vent (see picture of supply manifold)?
I’ll add onto the supply manifold a 1 ¼†x ¾†reducing T, a plug, a nipple, and an isolation flange. At this point, I’ll pressurize the system with water to test for leaks. Then I’ll add the new circulator and the other isolation flange and do a second leak test.
On the return side, the previous plumber left no expansion capability. Unfortunately, the elbow on the manifold goes to the second floor zone so I will have to drain the whole system in order to get the elbow off. The plan was to cut into the copper above the isolation valve before disconnecting the valve, nipple, and elbow. I suppose that I could cut into the nipple with a sawzall but then I’ll have to use some sort of union when connecting it all back up again. The advantage of this approach would be that I wouldn’t have to drain the second floor zone. Still, I think I’m better off draining the entire system and cutting into the copper.
If I drain the entire system, how does air get into the system so that the water drains out? Is it through the automatic air vent again? Or do I need to open the manual bleeder valves on the slant-fin baseboard radiators?
When closing the system up again, I will purge most of the air from the system using the boiler drains on the return side. I will also go to each baseboard radiator and open the bleeder valves to purge any air.
Thanks for any assistance.
--Bill
The question I have concerns draining & purging the boiler. In the first step of the project, I will be adding onto the supply manifold. I plan to shut the isolation valves (4) on the supply and return sides. I will also isolate the boiler water feed. I’ll open the boiler drain to drain water from the boiler and manifolds below the isolation valves. How does air get into the system to break the vacuum? Does one have to open the valve on top of the automatic air vent (see picture of supply manifold)?
I’ll add onto the supply manifold a 1 ¼†x ¾†reducing T, a plug, a nipple, and an isolation flange. At this point, I’ll pressurize the system with water to test for leaks. Then I’ll add the new circulator and the other isolation flange and do a second leak test.
On the return side, the previous plumber left no expansion capability. Unfortunately, the elbow on the manifold goes to the second floor zone so I will have to drain the whole system in order to get the elbow off. The plan was to cut into the copper above the isolation valve before disconnecting the valve, nipple, and elbow. I suppose that I could cut into the nipple with a sawzall but then I’ll have to use some sort of union when connecting it all back up again. The advantage of this approach would be that I wouldn’t have to drain the second floor zone. Still, I think I’m better off draining the entire system and cutting into the copper.
If I drain the entire system, how does air get into the system so that the water drains out? Is it through the automatic air vent again? Or do I need to open the manual bleeder valves on the slant-fin baseboard radiators?
When closing the system up again, I will purge most of the air from the system using the boiler drains on the return side. I will also go to each baseboard radiator and open the bleeder valves to purge any air.
Thanks for any assistance.
--Bill