the timing chain should not impact the cabin heat at all.
Is the engine temp fine?
if so - make sure that the interior cooling loop pump is working. It is the pump that forces the hot coolant through the heater core. It's just behind the the passenger headlight - with a taps coming off the upper rad hose.
if it is working, then it may be a nasty air pocket. when bleeding you have to turn your heat to full, to make sure to circulate that inner loop. It's tough in Texas, since the highest temp setting is 90 and often it's hotter than that outside - we can't get the heat to kick on!