CO sensor gone mad

[moskovskiy82]

Have around 5 nodes around the house and the latest one completed sends spikes from 50 to 800 ppm almost every minute. The only idea i have - it's happening because of the power supply (MQ-2 attached to the power supplies 5v and GND). Will adding a capacitor help out to smooth out the voltage? And what is the recommended capacity? Have tried already replacing the sensor