Z-Wave Thermostat ZTT000

[boxsterman]

I have been fighting with the ZTT000 for almost a week now and finally took it out!
First, it was the wiring...the instructions showed one thing, until finally found a NEW set of instructions which showed something totally different.
I have a simple central A/C system with electric heat. The old thermostat was a Honeywell T8401C with W, Y, G, R, C (5-wire) connectors. Based on the "revised" wiring diagram, the following connections were made:
W: White & black
Y: Yellow
G: Green
R: Red
C: Blue
The thermostat started just fine, registered on the Z-Wave network fine, came up in Homeseer 2.0 (although it took some time before the software picked up the current temp)- I could live with that...BUT here is the kicker...The current temp is 70, Heat set point is 75, Cool set point is 77 AND the A/C starts to push COLD air!
Could somebody shed some light on what is going on here...we are freezing!
Murat

 

[Spanky]

Try putting more difference between the heat and cool set point. You only have two degrees difference. That could be confusing the thermostat. Try 72 and 80 just to see if it is working.

 

[Squintz]

Sounds to me like you could have your heat and ac control wires backwards. It took me a few hours and lots of tinkering to get it working but eventually I did and it works fine now.

If you are freezing you may want to call and HVAC guy to come put it in for you and just fork out the cash. It might just be worth it.

 

[boxsterman]

Thanks for both responses, really appreciate it. I don't think the problem is with the wiring as it did heat at one point (when it was set to "auto"). The set point being close: that may be the problem.
However, now I have a totally different problem...tried to install the old thermostat and I think I shorted the darned thing (the blue and red touched each other briefly with a spark) so I am HOOPED. I called the HVAC guy and I will ask him to install the ZTT000.

 

[Rupp]

Thanks for both responses, really appreciate it. I don't think the problem is with the wiring as it did heat at one point (when it was set to "auto"). The set point being close: that may be the problem.
However, now I have a totally different problem...tried to install the old thermostat and I think I shorted the darned thing (the blue and red touched each other briefly with a spark) so I am HOOPED. I called the HVAC guy and I will ask him to install the ZTT000.

Good luck finding a HVAC guy that will get within a 100 yards of this or any other "modern" tstat. I searched for weeks to find someone who would install these and never did find an installer that would touch it.

 

[boxsterman]

Sounds to me like you could have your heat and ac control wires backwards. It took me a few hours and lots of tinkering to get it working but eventually I did and it works fine now.

If you are freezing you may want to call and HVAC guy to come put it in for you and just fork out the cash. It might just be worth it.

Could anybody tell me if they had experience with 5-wire, single heat/cool system and if the wiring match-up I mentioned in my earlier post is in fact correct.
My feeling is that the thermostat is not functioning properly.
If the thermostat is showing a current temp of 70 and the heat set point is 74, am I not correct in expecting the heat to come on?

 

[JKnox]

Couple of questions: do you have access to a voltmeter? And what where the original connections to the Honeywell t-stat?

Hopefully I can help. I don't have an ACT, but do have a RCS, and have had a bit of experience with automating the strip heat control. My A/C is a 5-wire style unit (both heating and cooling combined in the same box). I just donwloaded the ACT wiring manual, and it seems relatively straightforward. Where can I get a copy of the revisions you're talking about?

Here's what the "normal" colors mean (at least as normal as it gets here).

Red - 24VAC power from transformer used to energize the control relays.
Blue - Common for transformer and all relays.

Green - Fan control relay. Connect to red to turn on circulation fan.
Yellow - Compressor control relay. Connect to red to turn compressor on.
Orange - Changeover control. Determines whether unit is in cool or heat mode. Direction can be different depending on manufacturer. On my unit, energizing (by connecting to red) selects cool mode.
White - Strip heat relay. Connect to red to turn auxilliary heat strips on.

Most thermostats don't use blue at all. Those that do typically only use it to turn on lights and such. Touching it to red is bad (as you found out). It is possible that you blew the control transformer (especially if it has an internal fuse). Hence the voltmeter question. The first thing I'd do is verify that I still have 24VAC across blue and red.

Green, Yellow, Orange, and Red should be the minimum to get going. Don't energize yellow or white without green - you want air moving through the unit when those are on. And don't energize yellow for short periods and give it a few minutes between runs - kicking that on and off in rapid succession is a good way to buy a new compressor...

Jerry

 

[boxsterman]

Jerry...the original thermostat wire colors were Red, Blue, Yellow, White & Green.
And, yep, the fuse was blown on the transformer.
The revised document is no longer showing up at the URL. It is showing the old manual with the old wiring diagram which did not work.
According to Honeywell,
Red & Blue are 24V, Yellow is cooling, Green is Fan & White is heat.
The key is which wires of the ZTT000 should be connected to these 5 wires?

 

[brothers]

You basically need to find somebody who is knowledgeable in electronics to look at the schematics for both your Z-Wave T'Stat and your HVAC controller, and figure out exactly how it should be wired. Wire colors can be pretty arbitrary - most HVAC guys are oriented toward the non-electrical/electronic side of things, and just wire things up "the way they've always done it".

I'm in the process of installing a sophisticated set of communicating thermostats and zone controllers on a couple of ancient multi-zone hot-water boilers, and I can't really imagine an HVAC tech figuring out how to do it (I'm an EE out of MIT, and it still took a while before the light bulb went off - "cut this jumper, and put that contact in the zone valve common return").

- Dennis Brothers

 

[JKnox]

According to Honeywell,
Red & Blue are 24V, Yellow is cooling, Green is Fan & White is heat.
The key is which wires of the ZTT000 should be connected to these 5 wires?

Tell me about your system. Is it a heat pump? Or is it strictly resistive (heat strips) for heating? Sounds a lot like the latter (I've had one of these too). What I defined was for a heat pump. I suppose it could be a "smarter than the average bear" heatpump.

I'm guessing you're back on the original thermostat? It's time to figure out how the original worked. Which means it's time for the ole' voltmeter. Can you tell which lines are active when the heat is on? Your choices are: White, or Green and White (line should have voltage from it to blue). Or I'm seriously confused.

Also, is there any model number on the honeywell? Looks like I can look up the install manual for it from the honeywell site.

Can you tell me what was different in the newer ACT drawings? Or better yet, can somebody post the correct version?

We'll figure it out. It looks like the ACT connections are versatile enough to connect to darn near anything.

Jerry

 

[boxsterman]

Hello Jerry,
Here is the file for the Honeywell T8401C thermostat (with 5 wires) that was installed originally:

http://customer.honeywell.com/Techlit/Pdf/...00s/69-1494.pdf

I also have the ZTT000 file which is larger than allowed so if anybody is interested, I can email to you.
Thanks guys for all your help.

However, I do think that I should not need a HVAC guy to help me...ACT-Solutions or Smart Products should really be supporting this product!

 

[boxsterman]

Well, Smart Products stepped up to the plate and solved the problem! Thanks Pierre.
The issue was: I did not have the latest instructions and the wiring diagram. The key is (in my instance) to join White & White/Black wires together and connect to White off the wall (Heat) as well as Green & Grey to Green off the wall (Fan). But most importantly, set the operating mode of the thermostat correctly. This was not on any of the installation manuals I had and consequently, the thermostat was operating (or trying to operate) in default (15) mode.

 

[JKnox]

EDIT: Whoops, too late! Glad you got it figured out!

Ok, it's making sense now. Your blue wire is connected to the "C" terminal, no? If not, I don't
suppose you could tell me which wire is on which terminal?

I'm sending you a pm. It's ok to email me the revised docs.

In defense of ACT (did I just say that?) wiring up thermostats can be a whole lotta fun. Consistency in wire colors is just one thing, there's also so many different types of equipment, each with their own connection requirements.

At any rate, I think I can come up with something for you here once I've got my grubby little fingers on all the docs.

Jerry

 

[DrRick]

But most importantly, set the operating mode of the thermostat correctly. This was not on any of the installation manuals I had and consequently, the thermostat was operating (or trying to operate) in default (15) mode.

The operating mode is an interesting issue. I have a ZTT000 and gas heating, but the thing defaults to electric heating rather than gas (it's really difficult to get the non-existent electric heater to heat the house up to the set point ). I'm sure there is a way to force it to default to gas and keep it there, but I just have my automation software (Homeseer) send a 'Set Mode' to '7' command to it on system startup