Click here to Find a Contractor in your area.
Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.

Replacing Thermostats with Sensors

I have a job coming up that has eight Tekmar 510 thermostats that the owner wants to replace with sensors where room temperature can be controlled via the internet. Can someone recommend a manufacturer? Honeywell? Tekmar? Aprilaire?
Often wrong, never in doubt.

Comments

  • HVACNUT
    HVACNUT Member Posts: 4,215
    I've got a client using 15 Tekmar 561 WiFi thermostats (all located in the equipment room) for radiant. Thermostat sensing turned off, Tekmar 084 button sensors for ambient and floor sensors. They're set for averaging. Two mix temps for mud and WB. All work great. The house is in a weak area so he does have frequent issues controlling things from the app but I'm sure it's not too common. He's also got 12 Honeywell WiFi thermostats with RedLink for Mitsubishi City Multi systems and they're always dropping out. He's waiting on the IT guy to see what can be done.
    I just want him to put his phone down. Please. 
    STEVEusaPA
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 2,437
    edited November 2020
    Looking at the wiring diagram for the Tekmar 510 it appears you have more terminals than you need with jumper wires to connect the R terminal to another terminal. in some cases (if there are no jumpers) you will not be able to use a normal thermostat with R W Y G C terminals.

    It appears that in most cases you will be able to use a normal thermostat. Any of the internet thermostats like NEST, ecobee, Honeywell, or others.

    I know that you are aware of the dislike of Nest by some members of this forum, but your customer may already have a platform for their cameras or security system, That may be a contributing factor in selecting a thermostat that will work with that platform.

    The Tekmar510 is just a more elaborate set of normally open contacts that close for a call for heat (or cooling in the Tekmar 521) with a 24 Volt power source to operate the microprocessor and sensor control.
    Edward Young
    Retired HVAC Contractor from So. Jersey Shore.
    Cleaned & services first oil heating system at age 16
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 2,437
    Alan, get an idea of what the thermostats operate. Probably a Tekmar zone control of some type but it could be something else. That will help in selecting the replacement thermostats.

    Ask if the customer has any other internet operated devices.

    With that, Your decision may be much easier.
    Edward Young
    Retired HVAC Contractor from So. Jersey Shore.
    Cleaned & services first oil heating system at age 16
  • Zman
    Zman Member Posts: 7,013
    I recently worked through a job with my tekmar rep. He said about 40% of the custom homes he does use remote sensors with the t-stats in the mech room. The owner drives it with an Ipad.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • @HVACNUT and @Zman I'm heading in that direction now - thanks.
    @EdTheHeaterMan The existing Tekmar 510's are all free-wired to turn on zone valves and the boiler. There's no zone valve control unfortunately, only a large junction box.
    We did an Aprilaire system in SF in 2007 that has been flawless, but it had too many bells and whistles that we didn't need.
    Often wrong, never in doubt.
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 2,437
    I would include zone control panels to make future trouble shooting easier. Three controls with 5 to 6 zones each will be economical. I like Taco ZVC 406 for the simplicity but any of the residential controls will do fine. A label maker will add a nice professional touch.
    Edward Young
    Retired HVAC Contractor from So. Jersey Shore.
    Cleaned & services first oil heating system at age 16
  • Alan (California Radiant) Forbes
    Alan (California Radiant) Forbes Member Posts: 2,975
    edited December 2020
    I would include zone control panels to make future trouble shooting easier. Three controls with 5 to 6 zones each will be economical. I like Taco ZVC 406 for the simplicity but any of the residential controls will do fine. A label maker will add a nice professional touch.
    I'm with you.

    I just found out from the previous tech. that there is no wiring from some of the thermostats back to the boiler. The thermostats only control the zone valves and the boiler fires on outdoor reset. We are now talking about a Honeywell RedLink system.
    Often wrong, never in doubt.