Frequently Asked Questions; Technical Data - Tekmar 521 Installation & Operation Manual

Frequently Asked Questions

Symptom
Display powering
on and off.
Heat not on
Room is too
hot due to floor
heating being on
Cooling not on

Technical Data

Programmable Thermostat 521 Two Heat or Heat-Cool (Includes Sensor 079)
Literature
Control
Packaged weight
Dimensions
Enclosure
Approvals
Ambient conditions
Power supply
Relay
Sensor
– Included
– Optional
Slab Sensor 079 10' (3 m) wire
Dimensions
Enclosure
Operating range
Sensor
A Watts Water Technologies Company
Look for...
Measure voltage at
wiring terminals R
and C.
Mode Off or Cool
Floor Max
Floor Min
Mode Off or Heat
521_A, 521_C, 521_D, 521_Q, 521_U
Microprocessor control. This is not a safety (limit) control
0.6 lb. (290 g)
3-11/16" H x 3" W x 15/16" D (94 x 76 x 24 mm)
White PVC plastic, NEMA type 1
Meets Class B: ICES & FCC Part 15, CE
Indoor use only, 32 to 122°F (0 to 50°C), RH ≤90% non-condensing
10 to 30 V (ac/dc), 50/60 Hz, 1.8 VA, Class 2
30 V (ac/dc) 2 A, Class 2 circuits
NTC thermistor, 10 kΩ @ 77°F (25°C ±0.2°C) ß=3892
Slab Sensor 079
tekmar type # 070, 072, 073, 076, 077, 079, 084
3/16" OD x 1-1/2" (5 mm OD x 38 mm)
316 stainless steel, 10' (3 m) 24 AWG, 300 volt PVC insulated Zipcord
-58 to 221°F (-50 to 105°C)
NTC thermistor, 10 kΩ @ 77°F (25°C ±0.2°C) ß=3892
Corrective Action
The power supply transformer
may have limited VA capacity. A
transformer with a larger VA rating is
Thermostat must be in Mode Heat in
order to provide heating.
The floor has reached the maximum
operating temperature.
Lower the Set Floor temperature
Thermostat must be in Mode Cool in
order to provide cooling.
27 of 28
recommended.
setting.
© 2020 521_D - 12/20