Honeywell TH115-AF-GA/U Radiant Heating 120/240V Programmable Thermostat with Floor Sensor and GFCI

Replacement was an Exact match, easy install. Programming was the hardest part until I went to youtube. Do yourself a a favor go straight to youtube for programming.

This is a replacement for another floor warmer thermostat that burned out and could not be replaced exactly. First of all, the directions are in English, not translated from Chinese. They are easy to follow. But! The unit comes with its own temperature probe. Mine unfortunately is already installed under a tile floor that I did not want to tear up. I connected my probe and the unit registered 104F although the actual temp was 75F. I measured the resistance of their probe and mine and mine was about 3 ohms less than theirs. With these thermocouples the resistance goes down as the temp goes up. I put a 2 ohm resistor in series and the temp now read 82F when the floor was actually 75F. So to get the floor to an actual 83F, I raised the morning set temp to 90F. I could have experimented with a little higher resistor but I used what I had and the adjustment to trick the thermostat works perfectly.

Easy to set up and get running right out of the box. Bright easy to read display. If you are replacing an older model thermostat, check the sensor loop resistnce of your sensor wire with an ohm meter. Mine read 17 ohms. This new model comes with a sensor wire that measures 12 ohms. If that's your case, and you decide to keep using your old sensor wire, you may need to up the temperature setting on this thermosat by a few degrees in order to compensate for the higher risistance in the sensor wire. I did that and it works fine.

First, the Amazon site leads with this being the Honeywell Floor Heater Thermostat. It in fact is a Resideo Technologies, Inc thermostat under license from Honeywell. It is not UL tested, only tested under UL specification which I am learning with many Chinese made products is their way of getting around any kind of testing at all. I purchased this current one in July of 2023. Had it installed by a licensed electrician, and it worked until a November of 2024. It is the second one that I have had put in. The past one just refused to work. This one as you can see from the picture tripped the main circuit breaker to the house and had a catastrophic failure. I Just had it replaced with a different brand and will never trust a "Honeywell" thermostat of any kind again.

I left a 5-star review for the seller. The product gets 4-stars because the original unit (same model, but purchased and installed by a remodeling contractor) lasted < 6 years. That's twice the warranty period, but I feel an item such as this should last longer. Otherwise, the thermostat is easy to use, has a nice set of programming options, and works well.The original unit's display had gone blank. After verifying there was power to the unit, I bought the replacement, which was also blank. The seller had sent a nice email (via Amazon) to thank us for the purchase and say we should contact them if there were any problems. So I contacted them to ask about troubleshooting the unit. All representatives were busy, so I left a message. Mark, the owner, promptly returned the call. He was extremely professional, friendly, patient, and helpful. As it turned out, I had wired the unit exactly as the old one had been, but the wire pattern has changed. Note to self: always read the instructions. In fact, I had read the instructions - but I was reading the old users manual, which I had pulled out of a filing cabinet when troubleshooting the original unit. Second note to self: make sure you're looking at the correct manual. However, if I'd been paying attention, the wiring diagram is also on the back of the unit. I did not look closely at it because I'd already read the (wrong) manual. So if you are buying this as a replacement, BEWARE!It must be a common problem, because Mark guessed at it right away. Problem solved with Mark's courteous help. Thank you!Greg Harrington (on behalf of wife Mary, who's account was used for the purchase)

If you are reading this, you should be pretty familiar with your options. This unit allows for floor sensing and the modes allow you to heat to a targeted floor temperature, targeted air temperature, or a targeted air temperature while controlling the min and max floor temps. It also allows separate schedules each day with 4 settings per day.Things to know about this (if they matter to you):* You can use either 120 or 240v, depending on how you wire it.* The included instructions do NOT agree with the markings on the unit itself. Input/Output are different in the instructions versus the unit itself. I don't know if this is a typo or a translation problem. (I followed the unit markings and it seems to be working well.)* If you opt for a 24-hr (military/European style clock, you can only have CELSIUS temperatures. Otherwise you only get a 12-hr (AM/PM)/Fahrenheit display.* It does have a heat anticipator option if you want it either click on or off at a certain time or if you want it to decide when to turn on and off to reach the target temperature by a certain time.I like it and recommend it.

Stuffing all the wires into a conventional switch box is a challenge. Although I rated it as 4 stars for ease of use - it's because you have so many choices in heating times. You must read the enclosed manual! I bought this as a replacement for a unit that kept complaining it was shorting out (GFCI kicked in). I was pretty sure that there was not an electrical problem - I took several readings of resistances and could find no underlying cause. I know it was a bit of a gamble - but ripping up the floor was an option of last resort. New one is installed and working fine. If you are not comfortable working on 120V electrical lines then get a reputable electrician to install it.

I paid $10 extra to have the Honeywell branding on thermostat. Received a generic unit that was white labeled with some unknown brand name. Same part number and thermostat but different brand name. A little disappointed Still works fine.