hot water boiler zones

Timco

I have a Teledyne-Larrs hot water boiler with 3 zones or pumps. I am a HO who is very experienced in this subject except for the occasional problem such as this one. The boiler was here when my wife & I moved in. I had crackeling in the boiler when zone 3 (1/2" pipe) was running so I upsized it to 1" and the knocking went away with the increased flow...but now zone 3 'backfeeds' through the Grundfus pump and 'backheats' zone 2 through the return pipe, as zone 2's feed is cool but the return is hot. A meter verified the pumps zones are working fine. All 3 zones feed in a row into a 3/4 common pipe which takes it to the boiler, with 1" inlets. Should this common pipe be 1" or larger to provide less restriction? Zone 2 has a 11/2 pipe for it's return, and I assume it likes sending the returned water there rather than back to the boiler? As you can see, all 3 zones reduce to 3/4 prior to returning. I run the system at 175 degrees and 20 lbs.

Thanks for any advise out there,

Tim

kevin coppinger_4

oh boy...

that boiler needs some attention. It should have had a bypass installed on it. Probably needs to be repiped but try flow checks on both sides. kpc

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Timco

zones

Both sides? I anticipated needing to re-pipe the return side, but is there a benefit to upsizing it to 1" or 11/4"? What exactly do you mean by bypass? I understand the flow checks.

Tim

Timco

zones

should flow checks go on all 3 zones?

Empire_2

WOW!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Now that I got my 4' printer working...LOL, You do need alot of work on this system. Do you have flo-checks on all zones? what is the longest piping run, size of house, And always PUMP AWAY. I would bite the bullet and replace that lame horse to at least save you some fuel consumption cost. Also take a pic, further away so we dont have to replace our printer ink half way through the photo.

Timco

info

Sorry about the pic...House is about 1600sqf. zones 1,2 are about the same, 60-70 feet total because the boiler is central in the basement.Both are 11/2 original pipe. Zone 3 runs about 70 feet, the new 1" copper pipe I added. Like I said, this is what I got. So the pumps should be feeding, and not returning? I get great heat, and have insulated well. No flow checks at all. Did not matter until I separated the zones. Do you still want a better pic?

Empire_2

YES

I dont have much time to ans. your q:, but move pumps to supply side, expansion tank before the pump with the water feed between tank and AIR SCOOP if you wanna halp tith air elimination. also add Purge valves on returns x 3 to aid in start up air purging. These should also have a ball valve after the purge valve, be it a drain cock or purge and bal/ valve.
I hope this helped a-little. Dont FORGET the flo check's. Good luck.
Also repipe everything from about 10' and back to the boiler. Looks kind of bad.