Hello-
I am working on moving a baseboard radiator and need know how to drain the zone and then properly purge it back out. What's got me confused is my radiators don't have any type of bleed valves. How do I introduce air to thoroughly drain the system? Besides cutting in and just hoping I don't make too big a mess. I am going to sweat a few fittings so will need to drain thoroughly.
See the pictures below. I assume I should close off the zone at both ends and open the drain at the top left of the picture below. But I don't know how to open an air valve somewhere to let the water out.
The zone I need to drain is on the far left. It has a drain valve above the shutoff which for some reason does not have hose threads. The shutoff below the T is connected to the zone I want to drain and another zone. The next picture shows shut off valves for that other zone.
Below are the zone valves. The one farthest left is for the zone I am working on, and there is a shut off valve after it.
Last edited by PJmax; 03-28-23 at 05:52 PM.
Reason: resized pics/labeled pic
As much as possible, isolate the section of pipe that you need to cut. It needs to be able to flow to a drain. If you do not have bleeder air valves at the baseboard, air will be introduced when you cut the pipe. You only need to drain water to just below the level you are working on. No need to drain the first floor if you are working on the second. No need to drain the boiler if you are working at the first floor. If the drain is open and there is no water above, the cut will introduce air and there should be little or no water coming through the cut. Cut the pipe from top to bottom.
Make sure main water is turned off.
Make sure the thermostats are off - no call for heat.
Shut the boiler off.
Close Ra(return) and open Pa(purge). It may be easier to slide a piece a piece of hose on that pipe
as there may be too much water for a bucket to hold.
The zone valves are on the S (supply) side.
Close S valve.
Closing that valve near the zone valve will isolate that zone from the boiler.
After you get done with the repair. Leave boiler off and thermostats not calling for heat.
Close Pa (purge valve)
Turn the water supply back on.
Open S valve.
Set the zone you worked on to a call for heat. If your zone valves are powered off the boiler....
you may need to open that zone valve manually. Open the zone valve.... and re-open shut-off valve.
Check for leaks.
Open Pa slightly to purge air from the that zone.
When all the air is out..... the system should be purged and can go back into normal service.
Cutting the zone open will allow the water to leave thru Pa.
A shop vac is a great idea..... along with a few sacrificial towels.
Gropp: But I don't know how to open an air valve somewhere to let the water
Here is easy, long term heating system venting solution.
Install $12 Watts auto vents at high points of each zone, Are very reliable, easily opened for service. Has black knob on Watts to manually check, confirm venting or turn off. https://www.supplyhouse.com/Watts-05...Vent-3679000-p
Gropp: Before starting make depressurization and service easier installing tee with drain faucet and shut valve on line to expansion tank. Tanks are best located where easy to service/remove with ½” nipple at bottom. With nipple on top debris in water collects on top of bladder shorting life.
In Fig 2 is basic theory of air scoops. ”. 2.5 times pipe ID * ID = Inside Dimensions
As water flows thru line, if diameter increases, pressure temporarily drops slightly, facilitating air bubble release to high point of larger diameter where can be vented.
Hi all (again),
I am working on diagnosing a zone valve which appears to be stuck open. Unfortunately for me it is in the house I used to live in and now rent out and although the tenants are good, they have a dog that doesn't like me, so long story short I'm trying to reduce the number of trips over there.
They have reported heat coming in through the baseboards for the last month or so even when the thermostat is set below the temp of the room or just turned off. They stated they swapped the batteries when it started getting too hot in there, and did not notice a change. I checked the thermostat last week which appeared to be working normally. There was 24v between the red and white wires, and I believe 24v showing between white and the screw between the red/white. Red to blank showed 0v. (Pictures attached)
The zone valve in the middle (first floor zone, the one in question) seems to want to stay open if I try to cycle the slider on the bottom to the right (the other two cycle normally back to the left after being pushed to the right).
From what I read here the best troubleshooting method is:
Shut off power to the boiler and see if the valve closes. If it does disconnect yellow zone valve wire and see if it closes, if it does it is likely an issue with the wiring between the t-stat and zone valve. If it does not close it could be the power head has gone bad?
If it seems like it could be the power head can I take the power head off the zone valve to the right (for the basement, which never seems to need to turn on) and swap it, at least for the spring? Is there any reason to try and lube up the connector going into the valve?
How can I tell if the valve itself needs to be replaced?
Anything else worth doing to help troubleshoot?
[img]https://cimg2.ibsrv.net/gimg/www.doityourselft.com-vbulletin/2000x1504/img_4843_691bf178113ee404ffb4399234358e7e3351ca80.jpg[/img]
[i]Valve in the middle, after I tried cycling it. [/i]
[img]https://cimg3.ibsrv.net/gimg/www.doityourselft.com-vbulletin/1500x2000/img_4840_5be565ae4042288b24907031a3b4ba82a859f20a.jpg[/img]
[i]Valve in the middle is the one in question, the one on the right is rarely if ever used as its in the basement which stays warm enough.[/i]
[img]https://cimg6.ibsrv.net/gimg/www.doityourselft.com-vbulletin/1500x2000/img_4839_0c85b1d5ecd1d0568273bacd6500bf4169172e5c.jpg[/img]
[i]Tstat[/i]
[img]https://cimg8.ibsrv.net/gimg/www.doityourselft.com-vbulletin/1500x2000/img_4838_1de0026d7b062ee4676da3f915b48f10b5587fd7.jpg[/img]
[i]Back of Tstat[/i]
Thanks for any thoughts/insight!!
I finally replaced my 70-year-old gas-fired hot-water boiler with a new Weil-McLain CGa Series 3. The new boiler has an automatic circulator exercise routine. The circulator runs for 30 seconds if the boiler has not operated for 30 days. Perhaps this is recommended by various pump manufacturers? I'm glad the W-M boiler instruction manual told me that. Otherwise, puttering around the basement in August, I might have been spooked and tempted to call Ghost Busters.
03-26-23, 01:17 PM
