Looking for thermostat suggestions

[NJBILLT]

Upgrading from Homeseer currently using 2, RCS serial communicating thermostats.  Looking for suggestions to replace them.  A color touch screen and more elegant appearance then the RSC is desired.  Thanks for any ideas.

Bill

[paulbates]

I've had 2 of the Venstar Colortouch's for 5 years. I currently have the T7900 model. I've been very happy with them:

• Lots of HVAC features
• Mobile app for my wife to use
• Remote configuration/management web page for multiple stats / properties
• Local API - ISY integration has zero cloud involvement
• I also have 3 of their remote sensors: 1 on opposite living spaces for each stat, and one outdoors shared between them
• It uses the  Nodelink Nodeserver

Here's what Nodelink provides the ISY for use in programs

 

Paul

[jgcharlotte]

I bought two of the Honeywell Z-Wave thermostats.  They are not very sexy, and some folks have had problems with them, but so far they have been flawless for me.  Integrating them into the system was a snap and the response is immediate.  So far so good, I really like them.

[paulbates]

That’s a good point, they all have pluses and minuses 

Paul

[simplextech]

I'm "Thermostat challenged" as I use baseboard heating and woodstove for heat... the options are very limited for line voltage thermostat's... I use StelPro currently but I've been thinking of going with the NuHeat Signature but it's Wifi based but they have an open API and I've talked with them and they are open to us integrating.  So I don't know they are also expensive and when doing room heating that adds up FAST.

[johnnyt]

On 7/5/2019 at 9:17 PM, jgcharlotte said:

I bought two of the Honeywell Z-Wave thermostats.  They are not very sexy, and some folks have had problems with them, but so far they have been flawless for me.  Integrating them into the system was a snap and the response is immediate.  So far so good, I really like them.

@jgcharlotte, what data do you get in ISY from the Honeywell stat? if possible, can you post screenshot(s)?

I want to change my Venstar for a zwave stat because the venstar needs to be polled for updates and it causes intermittent problems, mostly (though not exclusively) because I've had to program a minimum run time using ISY otherwise the stat frequently short cycles my furnace/AC. Venstar tells me the fix is to have 2 deg deadband but that's too much variation, and not something I've had to have with any of my previous stats. I want real time "push" updates from the stat. (I presume that's what you mean by "response is immediate".)

Thanks

[jgcharlotte]

I never actually timed 'push', I know that it is immediate when making changes from the admin console.  I went to the stat and changed the setpoint  there while watching on my phone, I have to say less than a second when it showed up.

I have to say the only caution would be that there have been quite a few reports of the Honeywell stat losing z-wave communication (open it up and reset the z-wave board to fix) and possibly some quality control problems.  I saw these after I ordered mine but decided to go ahead anyway.  Both of mine have been flawless for several months and I'm very happy with them.  You can look on Amazon if you want to look at those.

Second screenshot is of functions available.

If AC is in 'compressor protection' delay, 'State' will say 'Pending'  (stat says 'wait').

 

[jgcharlotte]

4 hours ago, johnnyt said:

 the stat frequently short cycles my furnace/AC.

I'm not sure what you consider short cycling.  I agree, 2 degree db is too much.  I'm not sure what the db on the Honeywell is.

If you want to wade through it, I've attached a log from the last couple of hours from both units (top is most recent).  Outside temp is 94, both setpoints are 80.

[larryllix]

4 hours ago, johnnyt said:

@jgcharlotte, what data do you get in ISY from the Honeywell stat? if possible, can you post screenshot(s)?

I want to change my Venstar for a zwave stat because the venstar needs to be polled for updates and it causes intermittent problems, mostly (though not exclusively) because I've had to program a minimum run time using ISY otherwise the stat frequently short cycles my furnace/AC. Venstar tells me the fix is to have 2 deg deadband but that's too much variation, and not something I've had to have with any of my previous stats. I want real time "push" updates from the stat. (I presume that's what you mean by "response is immediate".)

Thanks

A huge dead band on the setpoints is not short cycling prevention and is not related to compressor protection. As I have found with most thermostat support, they have no idea what they are talking about and don't understand the terms, even when you use their exact lingo used in their manuals.

Short cycling prevention takes a timer, that survives everything, including power outages, if possible, that prevents the compressor from turning back on after it last shut off.

Here's an example. You have setpoints with a 5 degree deadband. The stat just shut off the A/C compressor as you walk across the floor and turn the stat to a lower setpoint because you feel it is too warm in the room. 10 seconds after the compressor shut off you demand A/C again and the compressor turns back on.

The pressure of the gases are still high inside the compressor and the compressor motor is slowly turning backwards, as the pressure equalises. Most AC motors will start any which way they turn first, and have windings to ensure they only start the correct rotation. But the motor is still turning backwards and will start backwards rotation direction!!

You hear banging and clattering and the fuses finally blow to the compressor.

The service man arrives, inspects the system and determines your compressor/motor unit is pooched!

Open your wallet for another $2-3K and survive the heat until it arrives and gets installed during peak season.

I have my compressor and thermostat on a different circuit breaker. Don't do that either.

I had my compressor running from stage 2 cooling on a Venstar Colortouch stat. Don't do that either. Second stage has no compressor delay protection, only the first stage. Get an ecobee.

[johnnyt]

@jgcharlotte Thanks. Is there not a setting for deadband adjustment? Is there a setting for MRT/MOT (min run time / min off time)? I mean within stat - not expecting that in zwave options. Assuming your AC isn't oversized, I'm guessing it's a 1 deg deadband given the 5 and 6 min cycles your logs show.

RE:short cycling. Without my (complex multi program) "minimum run time" mechanism, the stat will start a cycle (heat or AC) and stop after 2-3 minutes because the temp goes back to SP then it starts again 2-3 mins later (5 mins if AC due to compressor protection delay). This can happen repeatedly until the stat's max cycles per hour kicks in to implement a "minimum off time", which has the effect of implementing a 2 deg deadband during summer/winter peaks as the house heats up / cools down waiting for system to run. It also kills the efficiency of my system since for the first several cycles in an hour, it barely has a chance to start before it stops until the last cycle in an hour.

At first I thought I had a unit with a particularly sensitive temp sensor but as I've had to change the unit 3 times now (over couple of years), once because of wifi connection (and other) problems with unit, once because of a move from T5900 to T7900, and once as a goodwill gesture from Venstar for other glitches, including spontaneous reboots that haven't completely gone away (other reason for wanting a change), they've all had the same short cycling problem if left on their own.

[jgcharlotte]

4 minutes ago, johnnyt said:

Thanks. Is there not a setting for deadband adjustment? Is there a setting for MRT/MOT (min run time / min off time)? I mean within stat - not expecting that in zwave options. Assuming your AC isn't oversized, I'm guessing it's a 1 deg deadband given the 5 and 6 min cycles your logs show.

I haven't actually looked at all of the configuration parameters.  It is probably 1 degree db because I never see the actual and setpoint more than one degree difference and I don't notice any oscillation  .I know my units aren't oversized, in that case I don't know how you can avoid moderate short cycling if the stat is positioned properly, without big swings.

 

[johnnyt]

4 minutes ago, larryllix said:

I had my compressor running from stage 2 cooling on a Venstar Colortouch stat. Don't do that either. Second stage has no compressor delay protection, only the first stage. Get an ecobee.

Good point. In fact I was just recently reading about a zwave stat that did have 2nd stage cooling compressor protection but I can't for the life of me remember which one. I only have one stage cooling so not something I need but mention it here to point out that they exist.

I would also mention that I had to set my T7900 to 2 stages of cooling (even though I don't have 2 stages) for calls to the 2 stages of heating I have to work properly (one of the many "other" glitches). I once read a post that said "don't buy HVAC products from software companies - buy them from HVAC companies". I'm going to be leaning that way for my next stat.

 

[larryllix]

Short cycling can often be due to Electircal grid reclosers on the high voltage lines doing a line protection short outage. This is done to alleviate lightning strikes on the line after they arc to ground so that the system supply doesn't continue to arc in the same carbonised air path. What the user experiences is a short completely dead line and then usually an immediate live line again. If the fault does not clear it will do it again, increasing the outage time to say.....1 second, and then maybe 15 seconds the next time, and then finally give up the third of fourth try.

This is real hard on your A/C compressor and will likely damage it usually. Decent thermostats are designed to not allow this. When the power is cycled the stat should lock out the A/C compressor for the minimum on delay time. They all label the setting differently.

[jgcharlotte]

Looks like there are a number of configurable parameters.  I'm not smart enough to mess with most of them

Here is the manual:  https://customer.honeywell.com/resources/Techlit/TechLitDocuments/69-0000s/69-2486.pdf