How long will my system take to heat up?
It depends on a lot of factors, but a classic installation over ¾” plywood with NADWS spaced at 3” would take about 30 minutes to heat from 60F to 80F.
Conditions that would slow down the heat up time: cable spacing wider than 3”, concrete subfloors, uninsulated crawl spaces, very low start-up temperatures, thicker tile/stone installations (over ½” stone) or poor sensor placement. If the sensor is placed too close to the cable, it would sense temperature too early and turn off the system before it actually gets to 80 or 85 degrees. You can calibrate the sensor using the OFFSET feature in the 3iE thermostat or the WUDG-4999 thermostat.
Conditions that would favor a faster heat-up time: cable spacing closer than 3” and the use of insulation including Warmup’s WIB Insulation Boards. Warmup has tested and shown that with its ¼” insulation boards a floor can reach desired 80+ temperatures in less than 15 minutes.