Also, “C” wire requirements in tstats…
Legacy system digital tstats often come with the ability to “power steal” from the air handler usually necessitating the C wire (other leg of the 24v AC control voltage) or run purely on batteries switching “R”.
HOWEVER, some digital tstats can power steal this leg via “W” (heat call) or “Y” (condenser call) by back feeding a very low amperage current through those respective relays/contactors.
In real world application this often does not work well causing relays/contactors to “chatter” and/or simply not working at all in some digitally controlled furnaces (COUGH NEST).
I couldn’t tell you how many times I went out to a call about a non-functional Nest only to find that even after a years of working, suddenly contactors were chattering. Yup, no C wired up. Corrected that, problem solved.
My system is several years old (Lenox XP17 - 030 -230 ic, Heat Pump, 16.2 SEER, 2.5 Ton, R-410A, DLSC Series and Lenox CBX40UHV Air Handler). I believe this is the communicating Variable Speed Fan type.
From Lenox - Variable-Speed Blower Motor
High efficiency multi-speed blower motor maintains specified air volumes up to a maximum of 0.8 in. w.g. total external static. Multi-speed operation is achieved by the use of an ECM (Electronically Commutated Motor) motor. Allows cooling ramping profiles (field selectable) for enhanced
dehumidification. Motor accelerates and decelerates gradually, reducing start-up and shut-down sound. Leadless blower motor features simple plug-in connections. Motor is controlled by the iComfort® Communicating control that allows blower to operate at two of eight air volumes or speeds available. Speeds may be field selected on iComfort® Communicating control depending on size of air handler and air volume desired. See blower performance tables.
I havent found a thermostat (other than proprietary Lenox) that handles the variable speed. Do I have this right?
It is not the variable speed blower motor that’s the issue, it’s your tstat and how the system is setup up to operate. The part about “Motor is controlled by the iComfort® Communicating control that allows blower to operate at two of eight air volumes or speeds available” is a bit confusing- it’s not the thermostat. These settings are selected by a series of jumpers in the air handler on the control board.
You are correct that the thermostat does use a proprietary data protocol to “talk” to the equipment vs. applying voltage to a specific terminal to accomplish turning something on. Actually every manufacturer’s communicating system has their own individual protocols making it impossible to utilize anyone else’s tstat.
Sometimes going to a communicating system is required by such things as a lack of good wires between components (think 10 story condo, air handler on he 1st floor, condenser on the roof) as communication uses as few as 2 wires. Sometimes it’s required by the type of equipment you have such as high end variable CAPACITY (refrigerant, not blower speed) systems or by the type of zoning equipment you may have.
HOWEVER, in your case both pieces of equipment are capable of being legacy wired for 24v or for communicating tstats. Assuming your system is not zoned, this means you could revert back to using the legacy wiring provided you swapped everything over in your air handler, condenser, and new tstat. In your case you’ll need at least 5 wires at the condenser and 6 at the tstat (7 if you get a tstat that can do dehumidification during a cooling call) for everything to function properly.
iComfort tstats are actually a series of tstats with varying degrees of sophistication and abilities. Not sure which one you have so I can’t speak to what features you may be giving up to change to a different manufacturer’s tstat.
Google your model numbers plus “installation instructions” and pull-up the results from Lennox.com. Toward the end of each PDF you’ll see the field wiring diagrams for both communicating and non-communicating.
Please read thoroughly both sets of instructions taking into consideration any jumper links that may or may not have been cut on the air handler control board based upon your particular setup when installed.
Yeah, this is a bone I’ve been picking with Wyze since they first indicated they were considering creating a smart thermostat. Missed opportunity. Instead of focusing on an area that is underserved, they decided to challenge well entrenched competitors such as Ecobee and Nest. I long ago installed Ecobee, not interested in throwing away that investment, especially on a firm trying to play catchup. But, like many, I have an unmet need to control some electric baseboard heaters. Mysa makes a decent unit, but pricey. Fortunately my utility offered them at a rebated discount. Suggest others check with their utilities to see if Mysa is available to them under a rebate program. I’m a huge Wyze fan, but this is an area where they appear to have missed the obvious market need.
I do this with Home Assistant, I’m able to use presence control to dictate which temp sensor is used to determine the heating/Cooling control. The thermostat then bases its functions on the temperature of the room that is being used, not the arbitrary temperature in the hallway.
WEATHER/PIN CODE
I would love to see a weather forecast added (like on my ecobee), Also, having kids that like to turn on the AC, it would be nice if the lock out feature allowed you to add a pin code to unlock it. These should be relatively cheap (but premium feel) interface upgrades. Thanks for considering!
Looking a purchasing a wyze thermostat now actually (1/26/2021). We have a whole house humidifier, and live in Minnesota, When the humidity is set to around 50 %, and it gets below 20 outside (or WAY worse -20 or -30), the windows gather condensation, cold water pipes can drip, even the exaust vents in the bathrooms can suddenly erupt a sudden torrent of condensate water right on your floor (or your head!). We have to watch the temp outside constantly and adjust the humidity in the house to below the comfortable range. Would you Please integrate the humidity controls with an auto adjustment factor derived from an internet enabled weather temperature source? (Or tell me you already did!). Thanks!
Hey @mike.s , this has been said before, but this is a high value, underserved market.
Copying Nest or Ecobee with a similar, just cheaper device is only crowding the narrower market of pure 24v thermostats.
On the other hand, in real life many (most in my experience) houses have a combination of climate controlling that includes 110/120v and 220/240v. These include floor heating, baseboard heating, swamp coolers, and a number of other elements.
Virtually all of these are controlled individually and locally with a dumb thermostat or even a simple switch. Nobody (or virtually nobody, Mysa comes to mind but is far from ideal) has tried to make sense of this much broader market.
This is where Wyze should aim to provide a unique, differentiated offer. Enough copycats…
Also and somewhat related, do we have more information on the room sensors? Thanks!
Swamp coolers are something that most likely are controlled via a simple smart-plug but I’d be curious about ones with an actual thermostat. The cooling effect is quite minimal though given that it utilizes evaporative cooling, and thus has a humidity limit to where it matters. This is something that’s better handled through a completely different system.
The baseboard and floorboard heaters are something that varies by area, and I’m surprised those aren’t controllable.
This is funny. Most people here don’t know how real houses are built. I don’t know if it is that they are younger, more affluent, live in cities or modern apartments, or whatever. Nothing wrong with any of that, but there is a big blind spot.
Swamp cooler do exist as small humidifiers that plug into a socket. That may work as room humidifiers, but not as full house ones.
In many dry states of the US (AZ, CO, NM, NV, parts of TX, etc) these are used preferentially to AC for full house cooling in the summer months. They are big, roof installed and not plugged into a socket!
@ColoradoFrench - I finally gave up on Wyze serving the baseboard market. Pretty lame that @mike.s claims they don’t do high voltage. Excuse me, what voltage does a Wyze SmartPlug handle? Ohm you need to handle 240v, well that’s just two 120v poles. Simpler than the engineering that went into creating a robotic vacuum or a smart watch. I finally went with a Mysa, which I got at a fair price due to a utility rebate. Pretty pleased with it so far. Prof. Pete
I really don’t believe it’s a voltage issue. It’s a massive blindspot, lack of imagination, and Nest copycat issue. Wyze’s model so far has been to take something that people do and do it cheaper, not necessarily better or to venture into a much broader space.
Mysa is not bad, but it’s not quite what I want and at that price point (I don’t think I can get the rebates) and times the number of heating and cooling elements I have, it’s not reasonable.
Trying to decide whether I wait it out for someone to “wise up” or whether I go with relays and transformers… It’s definitely more work to do that as I’d need to create new “old work” electric boxes in the walls and wire them, which is tantamount to inspection, etc.
I think its more about liability issues vs. engineering. Note that Wyze doesn’t offer any smart switches, such a Feit, TP-Link/Kasa, etc. Such devices require consumers to know how to wire line voltages or hire an electrician. Wyze appears to be focused on scatter gun approaches to products, vs. a clear focus on delivering a complete product line/ecosystem. Notice that their entry into home security doesn’t offer a smoke or CO2 detector.
In respect to getting utility rebates on Mysa, check the utilities for your relatives that happen to live in other states. I live in CT, but had a relative, who lives in upstate NY, place an order for us, through her utility, as they offered a rebate. Still, as you note, to install the Mysa, I did have to “create new “old work” electric boxes in the walls and wire them”, but I am a retired engineer, so pretty easy for me. Prof Pete
Maybe. There’s liability attached to everything, but of course probably more in line voltage. That does not appear to stop a myriad of players in the electrical space, so it’s hard for me to believe it.
I really believe in unconscious bias/blind spot, because most of the folks working at Wyze have not encountered the full range of situations and their (indeed scatter gun) approach to product is not letting them identify or evaluate these opportunities fully. Moving fast to check boxes while using Google/Nest’s market research do the job of determining what should be built.
And I am with you, easy enough to create new old work. That’s not really what I was concerned about, more the end to end process that does not make it easy for many others to do so.
