after a clutch fan was changed I now have no heat while it idles. on 2002 Suzuki XL-7

unless I apply the gas I will not get heat. is this from the clutch fan being replaced?

2 answers
Thermostat, most likely, worn water pump impeller, possible.
Temp gauge reading at extended idle is??
may also have an air lock in the heater core. find someone that can evac cooling system to get all the air out.