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Two Stage Heat / Heat - Cool Programmable Thermostat (Includes 079 Sensor)
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$178.50 each
In Stock
Get 15 Tue, Jun 23
Order by today, receive Tuesday
MANUALS (4)
This item replaces: 510, 511, 512
Free Shipping This item ships free
Easy Returns No restocking fee for 90 days
Product Highlights
–
Programmable, 7 Day
24V, Low voltage
1 Heat/1 Cool, 2 Heat, 1 Heat
Horizontal
Hardwired
40°F to 95°F (Heating), 50°F to 100°F (Cooling)
Description
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The Programmable Thermostat 521 is designed for three different modes of operation: single stage heating, two stages of heating with a fan, or one stage of heating and one stage of cooling with a fan. Two auxiliary sensors may be added to measure the floor, outdoor or room temperature. A Slab Sensor 079 is included to measure floor temperature to protect the floor from overheating and enhance comfort. The programmable schedule supports either a 7 day or 24 hour schedule with 2 or 4 events per day. A permanent temperature hold button overrides the programmable schedule. An optional Adaptor Plate 012 is available to allow the thermostat to mount onto a single gang electrical box.
Features
Features
- 7 Day Programmable Schedule
- Backlight
- Cooling
- Fan
- Four Hour Battery-free Clock Backup
- Optimum Start
- Outdoor and Floor Temperature Display
- Permanent Temperature Hold
- Radiant Floor Heating
- Time Clock
- Two Stage Heating
Specs
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| Application: | Multi-Stage (Heat/Cool) |
|---|---|
| Stages: | 1 Heat/1 Cool 2 Heat 1 Heat |
| Programmability: | Programmable 7 Day |
| User Interface: | Push Button |
| Mount: | Horizontal |
| Options: | Large Display Fan Control Comes with Sensor |
| Power Method: | Hardwired |
| Temperature Range (F): | 40°F to 95°F (Heating) 50°F to 100°F (Cooling) |
| Enclosure Type: | NEMA-1 |
| Voltage: | 24V Low voltage |
| Color: | White |
| Height: | 3-11/16" |
| Width: | 3" |
| Depth: | 15/16" |
| Weight (lbs): | 0.6 lbs |
| Ambient Conditions: | 32 to 122°F (0 to 50°C), RH ≤ 90% non-condensing |
| Control: | Microprocessor PID control |
| Sensors: | NTC Thermistor, 10 k ohm @ 77°F |
| Floor Sensor Compatible: | Yes |
| Humidity Control: | No |
| Wireless: | No |
Questions?
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Call or text 888-757-4774
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Friday
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Saturday – Sunday
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Product Reviews
4.5 out of 8 reviews
88% would recommend this product
5 star
88%
4 star
0%
3 star
0%
2 star
0%
1 star
13%
Customer Images
Showing 1-8 of 8 reviews
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Radiant slab running 20° hotter than thermostat setting
Love the concept but this won't kick off boiler no matter how low I set air or slab temp. Turned boiler down from 120° to 100° (lowest possible setting) so it don't run 24/7 anymore. HELP!!
Miles
NJ
4 years ago
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Works Great
Easy to set up for radiant slab heat
Bob C
CT
4 years ago
Verified Buyer
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great features
Easy to wire in. Still trying to get the best settings for my radiant floor with my wood stove nearby. Should save with this unit over a non programmable one.
wrench
Southern New Jersey
6 years ago
Verified Buyer
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TEKMAR 521 Thermostat
I used it in a multi unit, sensing in two apts., very nice easy to understand operation.
One of the Tekmar room sensors on the other hand, sensed 10 * warmer than it was.
buzz
Mpls. Mn.
7 years ago
Verified Buyer
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Just what I needed!
I am using this thermostat with two probes to control a water to water heat pump. It works great.
Just Dave
Atkins, VA
8 years ago
Verified Buyer
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Great thermostat
Great thermostat. Nice looking and perfect working
Pawel
Ny
10 years ago
Verified Buyer
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Good control
I used for two radiant heat floor installations on a NYC school. It was the right product.
Vinnie, another plumber in NY
Ossining, NY
10 years ago
Verified Buyer
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Excellent Thermostat
This thermostat replaced three different thermostats that I was using for the in floor radiant heat in my shop.
I had one thermostat to conrol the maximum floor temperature. One thermostat to control the air temperature and one thermostat to control the auxialry electric forced air heat. The Tekmar thermostat controls all three of these with just one unit and does a better job at it.
Russ
Jonestown, PA
11 years ago
Verified Buyer
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Product Q&A
3 Questions3 Questions
Q: Does the outdoor temperature play a role in how the programming works or it just for information?
Asked by Jim 10 years ago
Add your answer
Verified Reply- SupplyHouse StaffCorrect, the outdoor sensor only provides a monitoring function (displays outdoor temp). The measured valve does not change the thermostat operation in any manner.
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Q: Does this thermostat have the pulse width modulating like the 518?
Asked by Eric 11 years ago
Add your answer
Verified Reply- SupplyHouse StaffYes, the thermostat uses Pulse Width Modulation (PWM) operation and cycles the heat on and off within +/- 1.5°F (1°C) of the temperature setting
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Q: Can you program this thermostat using the floor sensor only. It states that it monitors the floor, but doesn't say if it will call for or shut off heat from the floor.
Asked by AJ 11 years ago
Add your answer
Verified Reply- Supplyhouse StaffYes it can, but that needs to setup in one of the back end settings screens
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