Taco zone valve replacement

DIYStratton

Hello all, first time posting here forgive me if i mess up on proper posting etiquette.
I'm also new to hydronic heating systems, and plumbing and mostly anything else to do with a boiler.

I have a quick question about Taco zone valve replacements. I found a couple of my zone valves seem to be corroded. The plunger part seems to be stuck in so water is always allowed to flow through the valve. This also seems to allow for a small leak around the plunger part, which allowed the corrosion to spread to the electronics housing as well. So im looking into my options for replacing these units. It looks like it would take some plumbing work to replace the valves, like cutting pipe and soldering and I'm not excited about that, mostly because i dont have a lot of experience in that kind of work.

Is it possible to replace the inner "guts" of the valve without completely removing the valve housing? I'm wondering if i could just somehow remove just the plunger section of the valve and install a new plunger without removing the actual housing from the pipe system. Is that a good fix or a really dumb idea?

I tried to attach a few photos to show what im working with. hopefully they upload correctly

STEVEusaPA

https://s3.amazonaws.com/s3.supplyhouse.com/manuals/1249544647674/Taco_Replacement_Parts_List.pdf
Now where to get them is another question all together.

DIYStratton

sweet i guess that means its possible. I bet ill probably have to buy the whole assembly and just have a left over valve housing. Thanks for the parts list

rick in Alaska

I would try to see if you can loosen all the screws first. With that kind of corrosion, the heads might be stripped. Just move them enough to see if they will turn, and then re-tighten them. If you can get them all loose, then go looking for new guts.
Also, there is a strong spring behind that plate, so loosen them all evenly to allow it to push the plate off without binding.
You will have to shut the lines down before you can do this, and make sure the presssure is at zero. And, you are going to have to bleed the lines when you get done because you are going to lose a lot of water before you get them changed out.
Rick

Joe Mattiello

Hi DIY
looks like you received good information on your first post on Heating help; great website!! The 570 series zone-valves have replacements parts available including the valve seat assembly. it's pretty easy to change the seat assembly, if that's what went bad, and based on your photo's someone already did, hence the Phillip-head screws on one of the valves. Taco uses SS screws, so it should be OK to unscrew without snapping; no guarantees.
Rusting on the seat assembly plate could be from puddling, due to condensation when the head is straight up 12:00. If the valve was leaking, a true breach, you would have more water released from system, and fresh oxygenated water added from PRV will corrode other ferrous components in the system as well. You would see signs at the expansion tank connection which is ferrous.

If your getting bypass, you're thermostat might have perpetual demand keeping the valve open. Any problems regulating room temperature? if not, I would change the seat and go Christmas shopping. if you can't find seat only, purchase complete valve, and cannibalize it for seat, head may come in handy in the future:) Hopefully this was helpful. If you need additional assistance, perhaps help locating a dealer in your area, those Tech support technicians at Taco, 401-942-8000 are probably just waiting for your call. of course you can always call me; Merry Christmas