Help Removing Radiator without draining system (return elbow directional?)

[Europe72dead]

Hello,

I need to remove a few radiators to replace a floor but need help understanding the return elbow in the photo below. The supply has a shut off that I’ll use, the return doesn’t however it has this triangle pointing downward that I assume signifies flow direction. I’m trying to avoid draining the entire system because it’s getting cold out and the job will take a week.

Are these return elbows mono flow valves that will stop water from coming up once the radiator has been disconnected? I just want to be sure the radiator is truely isolated by just closing the supply valve side.

It’s a 2 pipe hot water system from the late 20s.

Thanks,

 

[Sylvan]

The system HAS TO BE DRAINED below the radiators your removing

 

[Sponsor]

 

[John Gayewski]

You have to drain the system to remove the radiators unless you have valves on both sides of the radiators. You could drain the system amd replace the 90s with valves.

 

[Sylvan]

You have to drain the system to remove the radiators unless you have valves on both sides of the radiators. You could drain the system amd replace the 90s with valves.

A normal hot water system has one valve on the supply, and the valve should have a small orifice to maintain constant circulation to hopefully prevent freeze-ups. Most installers today do not know the proper way to install a valve on an HW system. If you do decide to use a gate valve, it is advisable to drill a small hole through the gate to allow for constant circulation.

A steam system does have a positive shutoff, and the steam valve has to be fully open or fully closed

 

[Sylvan]

Hi,

The triangle on the return elbow is just a flow direction indicator, not a valve. Standard return elbows on a 1920s two-pipe system won’t stop water from coming up once you disconnect the radiators. Closing only the supply valve won’t fully isolate the radiator; a small amount of water will likely come out from the return side.

You don’t need to drain the whole system. Just have a bucket or towels ready and loosen the return connection slowly to catch the water. That way you can safely remove the radiators without emptying the entire system.

You are WRONG

First, the boiler feeder had to be shut off

Second, the system has to be drained BELOW the radiator being worked on

Third, A hydronic system is FULL of water even in the return, so it has to be drained completely below the rad being serviced /replaced.

 

[Fitter30]

Even if there were valves their 100 years old drain it. Get a refrigerator two wheeller move them across the room. Have two men unless young, tough and have a good back. Hope there is enough play in pipe to raise them to reconnect them. When your done with last radiator get a qt of Rectorseal 8 way boiler treatment. Amazon and others sell it. Also replace any auto air bleeds and coin vents at radiators and the tridicator gauge. Radiator valves need a spud wrench to remove and install the radiator side if replacing any valves.