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Looking for help with Taco ZVC 404-2 Zone Valve Controller and Taco zone valves

Looking for help with Taco ZVC 404-2 Zone Valve Controller and Taco zone valves


Old 03-09-14, 07:13 PM
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Looking for help with Taco ZVC 404-2 Zone Valve Controller and Taco zone valves

Apologies for the small novel here, but after reading many of the posts I felt all info was better than 50 questions In 2005 I built my own Peerless WBV-04 Riello F5 fired burner and Peerless partner PP-60 DHW system. I set it up with two circulators (one Taco 10 for 3 baseboard zones and 1 Taco 7 for the DHW). I selected the taco ZVC 404-2 controller and 3 Taco ESP075 motorized zone valves. Over the years the ESP075 motorized zone valves proved problematic and my service guy has since replaced 2 of 3 with newer Z075C2-1 valve units as the older units failed. I also installed neon lights in the circulator electronics box to indicate power at circulators. I really like the setup because I can easily diagnose a problem before the service guy comes over so I can tell him what to bring. I haven't had many problems other than the zone valves but noticed that the controller was turning one of the circulators on and off repeatedly. I assume it was the baseboard circulator but have not heard the event happen while I was down in boiler room. When I went downstairs it had stopped but noticed that the yellow (call) LEDs for zones 2 and 3 were flickering. I jumped out the T-stats and for a brief moment the call light came on zone valve spun and engaged the switch turning on red LED and closing relay to baseboard circulator... this lasted about 20-30 secs then shut off. I tried all of the other zones and nada all dead. I called my service guy who came over and told me that the controller board was dead and mine wasn't covered and that I really should go with another controller.. the service company hates the tacos because of the cost. I was really taken back by the selective coverage when they had no problem taking my money for the last 8 years. I figured I will call tomorrow and fight with the office manager. I had another ZVC-404 laying around that an electrician fried the Bus resister and green LED on by accidentally injecting 110v into a tstat line. Because I felt it was not something that should be covered by service contract so I bought and replaced the controller. Rather than wait until monday I decided to try and fix the fried controller by replacing the bus resister with 5 individual 2.2k resisters and put in a new green LED ten tested the controller - all seemed good. I swapped out the controller and everything worked but I noticed that the same 2 yellow LEDs are flickering.... Im really wondering two things.. 1) what the heck do the flickering LEDs indicate... I have an email into Taco but they are really slow to call back. 2) Was the service guy right? Is there a more reliable economical 4 wire zone valve system that supports 2 circs and will give me all of the indicator lights? The service guys seem to have their own recipe and cant wrap their heads around anything outside their recipe. I was extremely impressed with the wide scope of knowledge here and figured someone might be able to make a good recommendation.. I really appreciate any help you can provide.
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Old 03-10-14, 08:44 PM
Houston204's Avatar
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Have you tried posting in the boiler section?
There are some Boiler Gurus over there.

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