Replacement for Carrier multi-zone control

My Carrier Comfort Zone Center appears to have failed, and I'm trying to educate myself on replacement options. My local furnace shop says they don't make these any more and a replacement controller will cost $2946 if we can use the existing temperature sensors. That seems like a lot.

Here's the equipment running my 4-zone system, which really ought to be a 5-zone system but maybe they didn't make those when this system was installed, apparently in 1991 (I moved here in 2004):

Carrier Crusade gas furnace Carrier Comfort Zone Center control box near furnace Carrier Comfort Zone 4-zone controller/timeclock Zone dampers: PEI / AirPax

In case anyone cares about the problem motivating this questions: The "Carrier Comfort Zone Center" is mounted on studs near the furnace, gets 24 volts AC from the furnace, and is supposed to supply 10 volts DC to the thermostat, but instead supplies a voltage varying between 6 and 7 volts with a regular period of about 0.5 second. The circuit boards in the "Comfort Zone Center" look clean, and no components are smoking, oozing, or making crackling noises.

So, 1. Should I pay $2934 to replace this controller? 2. Should I consider the style of controller that takes input from four thermostats, instead of reading four actual temperature sensors itself? 3. Should I be looking at X-10 systems? RS485? Can I get something that plugs into my house's ethernet and provides a browser-based interface?

Much appreciative of suggestions, observations, and even illuminating insults.

Reply to
Peter Pearson
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Reply to
Bennett Price

Peter, Before I can help you; What is the model number of your Carrier Comfort Zone

4-zone controller/timeclock.

Jabs

Reply to
Jabs

Yes cost is $500.00 per channel and you do the installation DIDO

Reply to
Dido

There is an astonishing shortage of anything resembling model numbers on this equipment, or in the accompanying documentation. Does any of the following help?

  • Molded into the inside of the plastic controller enclosure face is "Part 140027-02".
  • Stamped in ink on the inside of the enclosure is "Nov 18 1992".
  • A paper sticker on what appears to be a socketed EPROM says "CZCT Rev 1.3".
  • A paper sticker on what appears to be the board's processor chip says "306DAR0415".
Reply to
Peter Pearson

[snip]

The answer:

Gazing dumbly at the controller board wondering why it couldn't deliver a simple +10 to the thermostat, I noticed that the +10 out was switched by a transistor whose base was driven by a bunch of logic. This led to the theory that the controller was purposely power-cycling the thermostat waiting for some kind of power-up message. (The voltage appeared to be switching between about 6 and 7 volts, not 0 to 10, but that might just be the inertia of my meter's needle.) An ohmmeter check revealed that one of the 8 solid-core wires in the cable between the controller and the thermostat was -- somehow invisibly -- broken. Replacing that one wire restored normal behavior.

Thanks to Bennett, Jabs, and Dido for their helpful attitudes, and to Oscar_Lives and his family for ensuring that wiring instructions will always be printed in block capitals and short words.

Reply to
Peter Pearson

Hello Peter,

I am having a similar problem ... Every so often I hear a rapid switching on/off from where the fan/blower is located. It seems that if I tap the main termostat (zone 1), main the Comfort Zone controller the noise stops. I was also told that this model is not made any more and the replacement would be about 3K.

If I read your response ... there are two cables coming in - one with three wires and another 5 wires ... I am curious to know

  1. How did you detect or find out which wire was broken?
  2. Did you rerun the entire cable (that has multiple wires)?

Thanks Ashu

Reply to
ashuWEMBA

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