Zone Valve

Dan_L

I have to replace the bottom zone valve because it is leaking. What’s the best way to isolate the valve to replace it? I’m confused with this radiant setup & worried I will lose a ton of water on the floor.

Would I close the valves at the other zone valves, close the valves at the pumps & drain it from the valve at the floor? What’s the best way to purge afterwards? We have a ton of boilers where I work. I appreciate any help

EBEBRATT-Ed

Shut down all power

Close the two ball valves between the two circulators and the 4 way valve.

Close the ball valve between the valve you are replacing and the supply manifold it feeds.

Close the two ball valves for the two motorized valves above the one your working on.

Close the supply valve coming out of the top of the boiler.

Put a hose on the drain valve on the right hand side of the boiler and drain the boiler and the piping there.

Your going to have to let air in to break the vacuum. I guess opening the boiler relief valve after you get the pressure down to 0 will do that although sometimes they will leak afterwords but you have no choice.

You only need to get the water level down to the top of the boiler. Probably 1 or 2 5 gallon pails of water will do it.

When your done open the supply valve on top of the boiler. Keep all the other valves shut. This will allow make up water into the boiler. Try and get air out through the relief valve and the air vent mounted on the
air scoop

Then open the valve to one zone and start the boiler. When the first zone is working open another zone and get that one working and so on Your going to have some residual air but probably not enough to air bind the zones. And the air should work it's way out from the vent on the air scoop.

HomerJSmith

If you shut off the boiler water feed and drop the sys pressure to zero, that would minimize water loss.
Shut off all zone valves and ball valves and get a 5gal bucket to catch the water that will leak out.
Have everything in place to make a quick change over, that means the kit to replace the zv stopper and gaskets. You most likely won't replace the power head as the leak is probably from the o-ring on the stem. Remove the powerhead and see if you can determine the source of the leak as a first step. To solder in a new valve body is more involved.

Big Ed_4

Why is a zone valve on a radiant loop ??? ... Wrong.....

Dan_L

Thanks so much for the replies! I have a much better understanding now on what to do.

I need to get more comfortable working on boilers. I’m going to order pumping away to start. Are there any other books you guys would recommend? Thanks

Big Ed_4

I would recommend a good hydronic tradesmen . You want to pipe your system correctly to work properly .

STEVEusaPA

Big Ed_4 said:

Why is a zone valve on a radiant loop ??? ... Wrong.....

Why is it wrong? It’s been done successfully all over the world.

MikeL_2

  I think it's amazing that your radiant  floor system is still working without leaks.
  I worked on dozens of those systems in the 70's & 80's that were installed right after ww2. Many had 3/4" copper manifolds & 3/8" loop piping. All systems that I worked on were converted to baseboard heating....

HomerJSmith

Are there any other books you guys would recommend? Thanks

Ya, Caleffi's Idronics magazine, free online, YOUTUBE. "Everything you wanted to know about Hydronics , but were afraid to ask." Also, Coffee With Caleffi. It's free, Free, FREE! Did I mention it's free.

Dan_L

I replaced that valve this morning. Everything went smooth. Thanks guys. I appreciate the help