It can be several things including the cont valve,if it has one, stopped up heater core, or thermostat. Have it checked out and don't throw parts at it as this can be expensive.
They are entirely different systems. One does not control the other. You have a problem in your heater core, heater control, water circulation or hoses.
Low coolant? Bad thermostat? Heater core plugged or airbound? Heat control cable not working?
The water is not circulating through the heater core or you have a control problem. If the heater is putting out heat then it is probably a control problem. If no heat then - water pump out, low on coolant, or maybe the therostat is stuck open.
I would suggest replacing it.
the heater control has a thermostat for the heater only. that thermostat needs replacing
Usually at the firewall either passenger side or middle follow the heater hoses
It does not have a heater control valve.It does not have a heater control valve.
I had this problem once with a different vehicle. You may check the heater control. That may be the problem. Hope this helps.
under the dash right hand side.
most of the time it the heater control unit on the motor not the heater core had same problem
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usually it is a vacuumn problem right at the heater control switch or sometime under the hood