Check the power base, supply, load and floor sensor before choosing the replacement wiring.
An nSpiration thermostat can be used in a suitable existing floor-heating installation, but a TH115 replacement is not automatically a wire-for-wire swap.
- Identify the complete TH115 model and power-base label, supply voltage, heating load and any remote power modules.
- For a line-voltage installation, follow the replacement thermostat’s LINE, LOAD, ground and sensor diagram. The nSpiration diagram lists 15 A maximum, 1,800 W at 120 V or 3,600 W at 240 V.
- For an older TH115-12VDC/CT230 system, use the dedicated conversion drawing. It replaces the low-voltage master arrangement with a line-powered nSpiration thermostat and nJoin modules; it is not the same change as replacing a standalone line-voltage thermostat.
- Identify the existing floor sensor and select the supported sensor type in the replacement control. The nSpire Touch WiFi manual supports several sensor curves; a sensor should not be assumed compatible simply because it has two wires.
Have a qualified electrician isolate all involved circuits, make the connections and complete the GFCI and operational tests. Keep the flooring manufacturer’s temperature protection settings.
Sources: nSpiration wiring diagram, TH115-12VDC/CT230 conversion drawing, and nSpire Touch WiFi manual (Sensor Type).