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Why can't I get heat?

My '04 Altima does not get heat. I have replaced the radiator, hoses, and thermastat. Had the heater hoses blown out(?) a week ago and still no heat. Was told the heater core is not the problem since there is no leak. Any ideas on what the problem could be? In addition to the above, I had to replace the engine last year…and now no heat!!!

Does it get heat while driving and not standing still?
If so, that’s a very common Altima problem but let’s hope that isn’t it because it is expensive to fix.

Could be that the thermostat is stuck open. That is relatively easy to fix but one would imagine that the mechanic checked for that.

It could be the linkage that controls the coolant going to the heater box.

Does the temperature gauge move at all? Does it move to the normal position?

Check the heater core inlet and outlet hoses. Do they feel similar? Most newer cars use air blend doors to vary airflow thru heater core. Heater core is always hot but if air is bypassing core than it won’t get heated. U need to crawl under dash area to check the blend door operation. And a non leaking heater core is no proof it is not plugged.

No, it does not get heat standing still or while driving. The mechanic who recently looked at it pulled the heater control panel down and said that was not the problem. The controls appear to be working fine and the tempurature guage do not go past normal.

Kenzie, It’s Not Just You !
Nissan Published A TSB (Technical Service Bulletin) In 2007 To Help Their Technicians Diagnose And Remedy “2002 - 2006 Altima: Poor Heater Performance,” All 12 Pages Of It.

Another One, TSB # NTB06-070 (5 Pages) Published In 2006 Covers “2002 - 2004 Altima; Manual HVAC [Heating Ventilation & Air Conditioning] Temperature Control Inoperative.”

TSB # NTB02-047c has a diagnostic flowchart and procedures for checking the system and rather elaborate system bleeding (air-purging) procedures. It could be worth having your mechanic have a look.

The other TSB has procedures for diagnosing and repairing/replacing temperature control parts on vehicles equipped with manual controls.

Sometimes you can search and find free downloads online or befriend somebody at a Nissan dealer who’ll make copies.

Good Luck !
CSA