(Redirected from LBBB). Left bundle branch block (LBBB) is a cardiac conduction abnormality seen on the electrocardiogram (ECG). In this condition, activation of the left ventricle is delayed, which causes the left ventricle to contract later than the right ventricle.
For instance, in the winter, if you set the thermostat to 20Â°C (68Â°F), it will activate the heating system when the house temperature drops below 20Â°C and will shut the system off when the house air warms up past 20Â°C. A setback thermostat contains an electronic clock.
Instructions. Press the System button on the thermostat, and set the system to Heat.. If the heating system does not respond to the thermostat, check that the heat setting on the thermostat is higher than the room's temperature.