Taco zone valves...

MikeR_3

Had a strange one today. While condemning a 6 year old Burnham (don't get side-tracked, this is MY thread, and it is not about boiler-bashing!), I noticed that the circulator was running, and none of the returns were hot. Checked each t-stat(none calling), and then tried to determine which of the zone valves was calling the boiler control. Spent WAY more time on this then I should have, and STILL had no answers, so I disconnected all of the wiring going to the valves, and checked each one for continuity across the end-switches (terminals 2 and 3). ALL 3 end-switches were closed. Doubting myself, I got a brand-new powerhead and checked the end-switch ... open. Swapped the new one with one of the old ones and wired up that zone. Everything works correctly. My question... what could cause all 3 zone valves to fail? (Before you ask, they were NOT manually opened.) I will be going back to replace the other 2 powerheads at some point, but would really appreciate any info I can get before I do.
Thanks

Weezbo

heck of a good reason For a zvc 506

one light on...you have power..one light on..that valve has power..one light on the zone valve has power and it is working correctly. esp valves have a light on them..light on has power and zone is open blinking? call for heat

MikeR_3

Sorry...

should have been more specific. Not sure of the model number, but it is the older type (Gold color, three terminals, no lights).

Ted_9

What he is saying is that it would be nice to use those controls.Patriot Heating & Cooling, Inc.

lchmb

I think

What weezbo is saying is now is a good time to add a taco zone valve control. I have seen a number of zone head's "fry" because of improper testing procedure, (not saying you did, could have been done previous). With a taco control box if the light is on, so is the zone head and circulator. If it's off it should be closed. Less mess, easier to trouble shoot, nice neat little box and it tell's you everything you need to know.

MikeR_3

Once again, sorry...

I re-read his post and, yes, totally misinterpreted it the first time. I am familiar with the taco zone controllers and agree that that would be a good addition to the existing system, but I don't know yet if the customer will go for it, as they are already on the hook for a block replacement, and seemed very concerned about the cost. If the zone valves were fried at some point, it would have had to happen prior to my arrival (first visit to the customer, and the circ was running with the returns cold when I arrived.) I guess my real concern is that whatever happened earlier to cause the problem could happen again. When I return, I will be replacing all of the wiring except the tstat feeds. What should I look for before replacing the remaining heads? With all of the wiring removed, I checked the voltage across the transformer and got 24 volts. Anything else?

lchmb

if they can't

go with a taco box I would just replace all wiring. First question I would have is how old are the zone valve's? Have they had a history of having to replace zone head's? Is the body itself going bad? After answering those I would rewire and go for it.
Question for you, I know you didn't want to discuss the boiler but has Burnham been contacted? If it is a warranty item they may be able to do a little more in the control department. Not to go off on a subject you didn't really want to get into, but I'm irish..can't help it..:)

MikeR_3

boiler...

House is only 6 years old. No history of valve failure. I will be contacting Burnham today (Monday). In the past, when replacing Burnhams on warranty, we only replaced the block, so a control upgrade would come out of the customer's pocket... No?