Temperature Controller, 2 Wire Room Thermostat Heating Thermostat Digital Thermostat with Large Screen LCD Display Wall Hanging for Control Room Temperature (White) : Amazon.co.uk: DIY & Tools
2-Wire heat only furnace for Nest E. The Nest is having problems staying powered. Can I use an external 24V power supply? How would I route the additional wires? https://www.amazon.com/dp/B07FT2RCG9/ref=tsm_1_tp_tc : r/Nest
12V/24V 110-220V STC-3008 Dual LED Thermostat Temperature Controller with Probe | eBay
thermostat wiring - Home Improvement Stack Exchange