Problems with Taco Zone Valves??
I have an issue with my forced hot water baseboard heat. I have 4 zones coming off a Burnham boiler. However one of the zones — the 2nd floor rear, where the master bedroom is, seems to be unable to shut off flow. So, while the thermostat is set to 66 degrees, it’s always 70 degrees in the room when it’s cold out. I think the issue is that the valve doesn’t completely close, so hot water “bleeds” through this zone when other zones are fired. However, I am not expert at this. I’ve called my plumber before (it happened last year) and he says “sometimes these things get some grit in them” and suggested I give it a light tap which seemed to loosen it up last year. However, this year that approach hasn’t worked, and what I think are the zone valves look horrible. The valves are Taco.
The whole system is only 4 years old! The system only fires zones for heating. There is no domestic water off this system (and it’s all gas fired).
I’ve attached some pics for reference. I think the titles are clear. I have a current problem valve, and I think one that will be a problem soon.
Any suggestions on what is happening here, and how to go about addressing it??
Replies
bk, are these zone valves in addition to the several pumps I see in one of the pics?
A great place for Information, Comraderie, and a sucker punch.
Remodeling Contractor just outside the Glass City.
Quittin' Time
I did'nt see any zone valves in the pic's, only pumps.
Those are flo-checks, a type of check valve. Parts should be available.http://www.taco-hvac.com/products.html?current_category=183
I did a quick google search on the nameplate data on those valves. They are check valves as shown here.
The fact that they're covered with ka-kah (BTW that's an industry term) just means that the bonnets of the valves are leaking a bit, but it doesn't mean that they're not working.
Marine Engineer
Thanks everyone for the info. Just went to the Taco site, and got a quick education on flow-cheks. Is there any danger to turning the knob (thumbscrew) too far to the left or right? (image in my mind is of my turning the thumb screw too far to the left, and creating a fountain of how water shooting up).
What's a typical frequency of having to replace these (assume our water is pretty moderate -- neither overly soft, nor overly hard).
Edited 11/21/2005 7:06 am ET by bk1000
It's hard to be 100% sure, since I can't see all of the piping, but it looks like you have four pumps on the return side and four flo-checks on the supply side. It doesn't seem that surprising that you would have some "ghost" flow in one ore more of the zones, since flow checks are designed more to stop water from coming back in the opposite direction than to stop water from being pushed through them, either by a pressure differential created by one of the other zones, or by gravity flow (hot water rises).
My neighbor had almost the exact same problem.
Taco pumps & check valves do not stop water from flowing when the system is not calling for heat , they just stop circulating it is all.
Heat always rises, so if the zone is above the boiler it naturally circulates through the system.
Most of the time this is not a big deal, usually zones are set to temps that are fairly close & no one notices a few degree difference.
But on my neighbors they had a hotwater maker on theirs so that was always calling for heat. To fix the problem I installed a solenoid valve on the zone, a normally closed valve that only would open when the pump was energized.
I have a Burnham boiler with 3 Taco pumps feeding radiant panels in my home. The installation just had its 10 birthday. Absolutely no problem. However, when we built an apartment (garage modification) behind us for the mother-in-law, other zones would "bleed" into the apartment. Thus, overriding the thermostat in that particular zone.
Taco makes a 1-valve that you can insert into the line of each zone. Here's the odd thing. I believe when one zone (say, zone 1) bleeds over into another, it does it by flowing backwards through the return line of zone 2. So the proper place to install the 1-way valves is in each RETURN line. They cost about $15.
Gary Curtis
Los Angeles
Just installed two new Taco circulator pumps on my system this weekend. Glad to hear the problem is not w/ them.
This may or may not help you much, but.....
Try tapping on the valve when that particular zone is active, and the valve is in the open position. This may dislodge the gunk more easily, and allow the flowing water to "wash it out".
My system has "flow control" valves directly above each circulator on the supply side ( 3 zones total). The way I understand it is that there is a spring loaded mechanism in the valve that keeps them closed unless that particular circ pump is pushing water to the valve. Ambient manifold pressure should not be enough to open adjacent valves.
However yours are not on the supply side, but I suspect that they would have to serve a similar function. Maybe too much gunk accumulated in them which stops them from closing all the way, and allows hot water to get into that zone when adjacent pumps are running.