EWC's UT3000 & ComfortBridge equipment compatibility

Post your questions and comments here.
John B.
Posts: 30
Joined: Fri Mar 13, 2009 8:57 am

Re: EWC's UT3000 & ComfortBridge equipment compatibility

Post by John B. »

That is correct...The ComfortBridge indoor unit simply needs a W signal for Heat or a Y signal for Cool.

This is the case, even if the ComfortBridge system is a Heat Pump.

John
John Brown :geek:
rhillson
Posts: 2
Joined: Thu Jan 12, 2023 11:54 am

Re: EWC's UT3000 & ComfortBridge equipment compatibility

Post by rhillson »

Thank you sir!
1stbscout
Posts: 3
Joined: Thu Jun 08, 2023 5:17 pm

Re: EWC's UT3000 & ComfortBridge equipment compatibility

Post by 1stbscout »

I am an AC contractor who has been installing invertor systems since they were first released. I have a 4 ton invertor, modulating furnace and an UT3000 for two zones, in my own home. This part is just history. Naturally I really should purchase a new UT3000 as the one I have is ver. 1.19 and if I attempt to use it the way I like, it will set blower codes due to the duct work issues with the upstairs being right in the middle between the 25% and 50% demand. But....I digress.
The real issue is not with anything other than the difference between Climate talk and ComfortNet communication protocols. They are not the same and the CTK of any type will not communicate with a board that has Climate Talk. Only with those with ComfortNet.
In the old "version" of things the thermostat was the brains of the system. It determined the what where and how of things. The new Climate Talk system gives control to the Air Handler/Furnace.
I just finished installing a new 19.2 invertor HP with a AMEV air handler and the system would not communicate with the CTK04AE (last gen of the ctk)It made no difference what I did. I was on the phone with tech support for 3 days non stop. Then being the "fool" I am I sat down and read the manuals for the 14th time. It was then I realized they were different. Climate Talk and ComfortNet are different. Naturally there is one other issue that was on this system.
The system apparently had a "floating" ground between the two units. So It would not communicate regardless of whether there was a thermostat connected or not. The end cure was to install the customers original thermostat AND even more important, Install a ground wire from the air handler ground lug to the suction line at the air handler and again at the HP. Then the system found the HP and everything was happy WITHOUT the CTK04.
Of course this brings up what is going to happen to the customers with the old ComfortNet systems if their lifetime unit replacement is called upon. Will they have to purchase a new air handler/furnace in order to use the rest of the system they already have?
John B.
Posts: 30
Joined: Fri Mar 13, 2009 8:57 am

Re: EWC's UT3000 & ComfortBridge equipment compatibility

Post by John B. »

1stbscout,

Sounds like you had a real adventure getting this equipment to work...

Actually, the term ComfortNet is what Goodman uses to identify their Climate Talk family of equipment. So they are not different...Goodman's ComfortNet family is utilizing the Climate Talk open protocol.

In a fully communicating ComfortNet system, both the Indoor unit and the Outdoor unit are rated ComfortNet.

In a partial communicating system (ComfortBridge) the Outdoor unit is still rated ComfortNet, but the Indoor unit is rated ComfortBridge. Thus, the system communicates between the Indoor and Outdoor units, but you cannot connect a CTK04 or a communicating zone control like the UT3000 to the Indoor unit.

The Indoor unit will only accept a standard Heat/Cool thermostat. Even if the system is a Heat Pump. You must use a standard Heat/Cool thermostat.

Now the grounding issue is very unusual! The Indoor unit's 24v common is bonded to the chassis, which in turn is grounded to the house grounding system. So it's not a floating ground. The Outdoor unit does not need 24vac (R or C). It only needs the Data 1 & 2 wires. It's assumed the Inverter has it's own 24vac outside. The 24v common of the Inverter must also be grounded, in order to be on the same "ground potential" as the Indoor 24v common. Otherwise, you will have a communicating issue. So, if the Outdoor unit could not "be found" until you ran a redundant ground (between the Indoor and Outdoor chassis) using the vapor line. That's indicative of a poor ground conductor on the outside unit, or poor grounding system in the home.

You don't mention any data voltage readings in your post...Do you recall what they were? And was the Indoor unit rated ComfortNet or ComfortBridge? Please specify...

Respectfully,

John Brown
John Brown :geek:
1stbscout
Posts: 3
Joined: Thu Jun 08, 2023 5:17 pm

Re: EWC's UT3000 & ComfortBridge equipment compatibility

Post by 1stbscout »

It took 4 days of going nuts attempting to use a CTK04 on this system. Lots of conflicting information etc.
I figure the ground issue was in the home wiring. Did all I could to troubleshoot that but, in the end, it was just easier to connect the two together in a way I knew would work.
I realize as I have done so much research on "ComfortNet" and climate talk, that they are kind of one and the same. The real issue, for me, is the loss of "proportional" control the earlier units allowed. As far as I can tell the thermostat used to be the "master" of the network. With ComfortBridge" it is now the furnace/air handler that is the master. Leaves me in the same situation I have in my own home. As soon as I removed the second CTK04 from the damper system my comfort level, and my electric bills became much like they were with the old system. Electric doubled and comfort dropped.
Voltages on the communication wires are not what they used to be. Measuring from common to either of data lines nets you equal voltages. As long as the thermostat is in the off position. After grounding the units with my "work around" the voltages were pretty much stable at 1.278 volts DC on both data lines. 0 differential between them.
As soon as the thermostat becomes active the voltages are indeterminate. I came very close to taking my 100mH oscilloscope out to the customers house and watching what was going on as the troubleshooting progressed.
The indoor unit was ComfortBridge. I worry about the outdoor unit as I have 8 or 10, may be more units I have installed over the past 10 years or so. With the warranty of unit replacement if the compressor fails. How is this going to work if it will not communicate?
Another thing I noticed after the system was up and running. There is a second communication "led" on the board. Although the paperwork states the communication section is all in the same place with the red and green led's, in all actuality there is a second "section" on the new boards below the network led's that also has to do with the communication. It is not in the paperwork as existing either.
I hope with all my confusing back and forth, I have been some sort of help. Thanks for listening.
Post Reply