Only getting warm air

[Padre]

2 weeks ago I had my timing belt, water pump and radiator replaced. I don't know if this is related at all but now my heater is only blowing warm air. I THINK this is intermittent the reason I am only guessing is because the weather varies so much here it's hard to tell if the heat isn't just better on warmer days.

Any ideas on the culprit? There is the odd sound of water flowing behind my dash sometimes- thought I should mention that.

 

[mtbtim]

You can check to see if your heater valve on the firewall is opening properly when you operate the temp control. Have somebody operate the temp adjuster while you watch the operation of the valve from the engine compartment.

Do you know if the shop that did the job replaced the thermostat? Maybe they installed the wrong thermostat and it's not opening up properly. Are you monitoring your coolant temp with something other than the analog needle gauge on the dash?

 

[JMat]

Any ideas on the culprit?[/B] There is the odd sound of water flowing behind my dash sometimes- thought I should mention that.

That sound of water flowing is because there is air trapped in the heater core. I had the same thing happen when I didn't want to take the time to burp the system properly.

How does the coolant level look when the it's cold?

 

[gamefreakgc]

2001s also have the electronically controlled blend door that has a known history of failing. If the heater valve operates fine, check the servo in the driver's footwell (hidden kinda well) to see if it's operating when you go from hot to cold.

 

[Padre]

Thanks for the help. Turns out it was a simple burping of the system. I should have but would have never considered starting there.