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Pelican Technical Article:

Heater Valve Replacement

Nick Czerula

Time:

1.5 hours

Tab:

$100

Talent:

***

Tools:

Small flat-head screwdriver

Applicable Models:

BMW 323Ci Coupe/Conv (1999-00)
BMW 323i Sedan/Wagon (1999-00)
BMW 325Ci Coupe/Conv (2001-06)
BMW 325i/xi Sedan/Wagon (2001-06)
BMW 328Ci Coupe (1999-00)
BMW 328i Sedan (1999-00)
BMW 330Ci Coupe/Conv (2001-06)
BMW 330i/xi Sedan (2001-06)

Parts Required:

Heater control valve, engine coolant, hose clamps

Hot Tip:

Replace hose clamps during procedure

Performance Gain:

Repair faulty heater control valve

Complementary Modification:

Change thermostat, flush cooling system

BMW E46 models are equipped with a climate control system or HVAC (called IHKA by BMW) which automatically controls cabin temperature once a temperature is set on the HVAC control head in the center dashboard. IHKA controls air-conditioning, heating, internal blower motor operation and numerous air outlets. The electronic IHKA control module governs the operations of the following components:

  • Heater valve in left rear of engine compartment; controls the flow of hot coolant to the heater core inside the IHKA housing underneath the center dashboard.
  • AC compressor in the engine compartment, driven by engine accessory belt.
  • Blower motor underneath the dashboard behind the glove compartment; motor speed modulated using the blower final stage.
  • Front and rear air outlets; nearly a dozen electric stepper motors attached to vent flaps control the flow of fresh or recirculated cold and warm air to windshield, face-level vents, foot wells and rear compartment.
  • Engine cooling fan; IHKA microprocessor and engine control module (ECM) determine operation and speed of cooling fan.

The heater valve controls the flow of hot engine coolant to the heater core. The valve is comprised of hose fitting and an electric solenoid that blocks or allows engine coolant flow. If the electric solenoid in the valve fails, it blocks coolant flow so that you get very little to no heat inside the passenger compartment. A quick check is to warm the vehicle up and then turn the heat ON; both heater hoses should be hot to the touch. If one hose is cool and the other is hot the solenoid is not allowing coolant flow. You could also have a bad signal to the valve; it is a two-wire circuit. Using a wiring diagram, you can identify the ground and battery positive feed to the solenoid, and test for proper voltage when the heat is ON.

Keep in mind that when your car was serviced before, parts may have been replaced with different size fasteners used in the replacement. The sizes of the nuts and bolts we give may be different from what you have, so be prepared with different size sockets and wrenches. 

Protect your eyes, hands and body from fluids, dust and debris while working on your vehicle. If you are working with the electrical system, disconnect the battery before beginning. Always catch fluids in appropriate containers and properly dispose of any fluid waste. Recycle parts, packaging and fluids when possible. Do not work on your vehicle if you feel the task is beyond your ability. 

Vehicle models change and evolve, as they grow older, so the vehicle shown in our illustrations may vary slightly from yours. If something seems different, let us know and share your info to help other users. Do you have questions or want to add to the article? Leave a comment below. When leaving a comment, please leave your vehicle information.

Lift and support the front of the vehicle safely. Remove the engine splash shield. See our tech article on splash shield and reinforcement plate removing.

Drain the cooling system.

Working at top of radiator, loosen coolant expansion tank bleeder screw (green arrow).
Figure 1

Working at top of radiator, loosen coolant expansion tank bleeder screw (green arrow).


Place a 3-gallon bucket under left side of radiator.

Working at lower left side of radiator, remove radiator and coolant expansion tank drain plugs (green arrows).
Figure 2

Working at lower left side of radiator, remove radiator and coolant expansion tank drain plugs (green arrows). Allow coolant to drain into bucket. Once coolant has stopped dripping, reinstall radiator drain plugs.


Place empty 3-gallon bucket under right side of engine, near suspension sway bar. Working at right side of engine block near engine mount bracket, remove engine block drain plug.

Some engines will have a 13mm hex block drain plug.
Figure 3

Some engines will have a 13mm hex block drain plug.

Some engines will have a 6mm Allen block drain plug.
Figure 4

Some engines will have a 6mm Allen block drain plug. Allow coolant to drain into bucket. Once coolant has stopped dripping, reinstall block drain plug. Replace heater valve:

Replace the heater valve:
Remove the air filter housing assembly fasteners (yellow arrows) and disconnect air flow meter electrical connector (green arrow).
Figure 5

Remove the air filter housing assembly fasteners (yellow arrows) and disconnect air flow meter electrical connector (green arrow).

Loosen air flow meter clamp (green arrow), then disconnect duct from air flow meter and remove air filter housing from engine compartment.
Figure 6

Loosen air flow meter clamp (green arrow), then disconnect duct from air flow meter and remove air filter housing from engine compartment.

Disconnect electrical connector by pressing release tab and pulling off (green arrow).
Figure 7

Disconnect electrical connector by pressing release tab and pulling off (green arrow).

Loosen hose clamps (green arrows) then remove coolant hoses from heater valve.
Figure 8

Loosen hose clamps (green arrows) then remove coolant hoses from heater valve.

Pull heater valve straight up and out of mounting brackets, be careful not to lose the rubber mounts.
Figure 9

Pull heater valve straight up and out of mounting brackets, be careful not to lose the rubber mounts. Install new valve into mounting bracket, connect electrical connector and install hoses with new hose clamps. Fill and bleed cooling system. See our tech article on draining and filling your cooling system.

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Comments and Suggestions:
Clar Comments: My car is BMW 318i 2002 RHD model. Initially AC blows a bit cold air on the passenger side and hot on drivers side. Today i had it regassed then all the vents are now not blowing any hot air. Fuses are confirmed ok, compressor is kicking in. The tech concluded that the compressor is 99% faulty because he's saying that even when he push the gas pedal, the high pressure is barely moving.

Im researching and read about the heater/water control valve. I'm not sure if that's the culprit or its really the compressor. I just dont want to spend money on replacing the compressor which is expensive, and turned out to be a cheaper part's fault.

Or would it be the Final Stage Resistor?
September 23, 2017
  Followup from the Pelican Staff: If pressure isn't high enough, the compressor is likely faulty. - Nick at Pelican Parts  
MortenF Comments: My car is a 1999 E46

It blows only cold air on auto, and only through the 4 face vents. Always hot air through windscreen and by the feet. Any ideas?
July 31, 2017
  Followup from the Pelican Staff: Most likely a mode or blend door issue. if A/C pressure is normal and the system does cool, has to be a heater box issue. Also confirm the heater valve is not sending hot coolant to he heater core. - Nick at Pelican Parts  
Mathtchr8 Comments: I have a 2003 BMW 325i. CAR had been stored for 2 years.

AC was working fine, suddenly quit and all air was blazing hot. Checked the clutch and it was not engaged. Parked the car and when the engine cools the AC works again but then stops.

Coolant level is normal but have not checked Freon level. Suggestions?
June 2, 2017
  Followup from the Pelican Staff: Sounds like you have a pressure issue. If failing when hot, it could be over-pressure due to a restriction or faulty condenser cooling fan. - Nick at Pelican Parts  
Neek Comments: '00 323 vert EU spec

volcanic heat from all the vents even if set on lowest temperature.
Just replaced the heater control valve with an OEM one and bleeded the entire circuit properly
problems stills
is there something mechanically related to cold/hot air flow into the area of the final stage resistor?
thnx
May 22, 2017
  Followup from the Pelican Staff: have you confirmed hot coolant is not getting to heater core? I would start there before digging too deep. - Nick at Pelican Parts  
bluebird Comments: hello my E46 BMW 316i has an intermittent Problem with the heater. sometimes only blowing cold air 22 degrees . if I turn the temperature up over 26 degrees heat will start to flow into the cabin. any ideas of the issue.
April 11, 2017
  Followup from the Pelican Staff: The problem could be with either the heater control valve or the controller. First confirm the heater control valve is sending hot coolant to the heater core when you have it set to heat. If so, check if the blend door is moving to hot from cold when changing temp. - Nick at Pelican Parts  
Adam Comments: I have a 2000 E46 318i. I can't get cool air through my vents. It blows hot regardless of being on the cool setting. The blend door is working well as I can direct air with no issue. The coolant system has just been flushed and radiator and thermostat replaced. I'm thinking the heater control valve? Any ideas?
April 5, 2017
  Followup from the Pelican Staff: Yes, I am with you. Sounds like the heater control valve is stuck open. Try clamping the hose out of the valve to block the flow (use flat jawed hose clamping pliers), does the heat stop? - Nick at Pelican Parts  
Rick Comments: Comments: I have 2 issues in the same system that may or may not be related. 2005 BMW 325i automatic in Florida.
1. temp gauge slow to rise to half way mark.
2. No heat from heater.

It gets to half way after driving a bit. On idle warm up there is no significant temp in upper or lower hose based on touch. After driving a bit the top hose seems slightly hotter than lower.

I have not checked the hoses going into heater core, but will next time. I am in Florida and it gets cold but we are talking 40degees cold it's in the 70's now.

My thought is the main stat is stuck open, or heater valve stuck closed.

Suggestions?
March 19, 2017
  Followup from the Pelican Staff: Thermostat OR could also be a bad water pump. Since you're having the heater issues I would tend to sway to faulty water pump, because the flow may be less that what it should be. - Casey at Pelican Parts  
bdjohns Comments: The solenoid on top of the control valve is getting hot and the car is not running, just with the key on. Is this normal?
February 6, 2017
  Followup from the Pelican Staff: Yes, these solenoids are powered closed, so if you have the controls inside the car set to cool, then the solenoid should be powered and will get hot. - Casey at Pelican Parts  
Gman209 Comments: heater stops blowing hot on long drives short driving its hot.
February 6, 2017
  Followup from the Pelican Staff: I have seen this before, on that car it was a result of the heater valve coming apart internally. You can disassemble the valve once removed from the car and likely you will see that the rubber seal for the plunger is coming apart and partially blocking the flow of coolant to the heater core. - Casey at Pelican Parts  
24 Comments: I was driving and my 323i e46 started overheating I will come to a complete stop and my car Will go to normal tempature and also my heater won't blow hot air as well anymore!!
February 6, 2017
  Followup from the Pelican Staff: Check the basics first, make sure the coolant level is topped up. This sounds like a problem with the thermostat, or water pump. I have seen both of those items cause this issue. If you have access to an infared thermometer you can check to make sure that the lower radiator hose is warm while the car is overheating. My guess is it will be cold which says that the thermostat is preventing the coolant from flowing through the radiator, OR that the water pump impeller has failed to create the necessary flow in the cooling system. - Casey at Pelican Parts  
Love-my-beamer Comments: If it is restricted as you suspect, how do I fix it? repeal & Replace?
January 31, 2017
  Followup from the Pelican Staff: Replace with new. - Nick at Pelican Parts  
Love-my-beamer Comments: Hi Nick, how do I check the heatercore flow? And how do I fix it if restricted?
I still don't think that's the problem, heater was working perfectly before couple of months ago I could feel the first warm air coming through after driving only 1km when started cold.. And there was heaps of warm air available out of all vents. Can a heatercore become restricted overnight? Thanks for your thoughts
January 30, 2017
  Followup from the Pelican Staff: Remove a hose and confirm coolant is flowing at the same rate being pumped. RUn the coolant into a large bucket to prevent spilling.

They usually become restricted over time. - Nick at Pelican Parts
 
Love-my-beamer Comments: Hi again, yes, it is just like you described. Water comes out of little hole at top of radiator and increases when revs go up..
How should I proceed? Thanks
January 18, 2017
  Followup from the Pelican Staff: Then you have a well bled system. I would check if the heater core has become restricted. Check it for good flow. - Nick at Pelican Parts  
Love-my-beamer Comments: Hi Nick, I have a 325i e46 2001. Recently had coolant level go low showed indication on dash. Waterpump was leaking so replaced that, refilled and bled system with nose up. However since then heater not working at all, just blows air. Checked heater valve and both hoses go warm/hot so valve is ok I think. Squeezing hoses visibly pushes water into radiator. Funny thing because before all that, heating was working fine, so also thinking heater core flow should not be the problem. Is it possible there is an airblock to or in the heater core? And how could I fix that? Or any other thoughts you have much appreciated! Thanks heaps
January 15, 2017
  Followup from the Pelican Staff: I would assume it is an air pocket, if it was working prior to the leak. With the engine running, is there a steady stream of coolant flowing from the small hole in the reservoir? Raise engine RPM, does the stream increase? - Nick at Pelican Parts  
Noel Comments: I have a 2000 323i. My issues are my AC and heater will randomly blow worm air. When is raining, all my window will fog up. I recently changed my HCV, AC evaporator temperature sensors, climate control unit, final stage resistor and even bleed the cooling system. None of them fixed the problem. Any advice or suggestions?
January 8, 2017
  Followup from the Pelican Staff: Assuming auto climate control, could be an issue with the cabin temp sensor. Best bet is to check for fault codes and monitor the temp sensor when the heater is on. - Nick at Pelican Parts  
Laptop Larry Comments: HI we have a 2002 BMW 318i E46, the heater control solenoid appears to be dual. is there a repair kit for this? Many thanks in advance
November 12, 2016
  Followup from the Pelican Staff: Yes. Give The Pelican Parts parts specialists a call at 1-888-280-7799. They can figure out what part or repair kit you need.
- Nick at Pelican Parts
 
Harry Comments: 1999 BMW 328I. I have a problem with my heating that is either the heater valve or heater core. When the car is warmed up, there is no heat through the vents when the car is idling. When the car is revved up or as I am driving the car, then heat begins to come out until I am at a red light and then cold air begins to come out. Also, all of my windows frost up inside when it rains. I have replaced the water pump and thermostat.
October 1, 2016
  Followup from the Pelican Staff: If the heater valve is sending hot coolant to the heater core, the heater core may be plugged. Check for hot coolant entering it at idle, is the exit hose warm as well? - Nick at Pelican Parts  
SoColdCananda Comments: 2001 BMW 325 xi E46. Overheated engine once upon a time. Replaced thermostat, water pump, and expansion tank. Engine now runs at normal operating temp but was never able to get heat out of vent/defrost ever again. Blows cold. Intermittently blows cold. Going to check if water valve is seized shut tomorrow. If not I suppose I'm buying an intake gasket and some coolant pipes. What do you think?
September 17, 2016
  Followup from the Pelican Staff: If no heat, it is either the valve, trapped air or a restriction in the system. - Nick at Pelican Parts  
john Comments: I had it checked and it's not the refrigerant. Whatever it is, it's affecting the heater because it only blows hot air through the window defrost.
August 22, 2016
  Followup from the Pelican Staff: If you are getting warmth on one side, the valve is not likely the cause. More likely one of the blend or mode doors is faulty. - Nick at Pelican Parts  
Jhigbee Comments: On my 2003 M3, the AC on the two driver side vents work well but the two passenger vents blow warmer. Also the heater doesn't work at all unless I use the window defrost. The window defrost blows hot. Is the my heater control valve that has gone bad?
August 21, 2016
  Followup from the Pelican Staff: Sounds like a low refrigerant charge. The evap is likely warming up on the left side. - Nick at Pelican Parts  
B Comments: 2000 528i
No coolant flow.
I know my iihka valve is junk.
I've removed every hose, radiator, thermostat,and flushed with water.
My question, if the ihka valve/pump is junk, will that prevent the cooling system from pressurisiing and achieving proper coolant flow?
My next play is too replace and cross fingers and hope I achieve coolant flow. I'm stooped. Thank you
July 31, 2016
  Followup from the Pelican Staff: It could block flow to the heater, not the cooling system.

Your issue is more likely to be a faulty water pump or restricted radiator. - Nick at Pelican Parts
 
Rob330XI Comments: 2003 330XI, Temp set to 59 and AC on full. Center set to 3 blue dots. Heat comes from all floor vents and Defrost. Cool comes from two side vents. Basically, full time heat no matter what settings and when I turn on AC I can get it from side and middle vents by manipulating the settings. Will replacing the HCV turn off the heat? It is 90+ degrees out and I need to get rid of the heat inside the car. It won't turn off.
July 12, 2016
  Followup from the Pelican Staff: It's possible. To confirm, check if the heater valve is allowing hot coolant to the heater core all the time. - Nick at Pelican Parts  
texaslonghorn Comments: 2004 E46 M54 325Ci late production. Just completed a major intake system tear down/clean up/replace - nothing to do with the cooling system. Now am getting error codes for coolant temp sensor high voltage, the heater valve is really hot even when engine is cool seems to be using electricity but no noise and the temp gauge is pegging out on hot. This happens when the engine is cold and when key is on accessory.
July 10, 2016
  Followup from the Pelican Staff: Check the wiring to the coolant temp sensor. It may be unplugged or pinched. - Nick at Pelican Parts  
Alvin Comments: My car is a 2003 325i. I've replaced my heater valve already the previous one was very moldy with coolant and would not close. Floor and windshield still release hot air when trying to use AC. I've tested points connection points and it looks like no voltage is going to the heater valve. Do you happen to know what controls the power to the heater valve on how much coolant it will allow through?
June 7, 2016
  Followup from the Pelican Staff: The normal state is open, so when command closed power and ground can be present. To see if this is your issue, unplug the valve, then close it using fused power and ground. If the problem goes away, look for an issue with the heater control unit.- Nick at Pelican Parts  
HotFoot Comments: I have a 2001 330Ci - cold air blows from the dash vents, but extremely hot air blows constantly from the footwell vent even when the option to blow at my feet is not pressed. Just had the battery, crank case valve, and hot water pump replaced, also recharged the entire A/C system and still not working. Any thoughts on what it could be at this point? Thanks!
June 2, 2016
  Followup from the Pelican Staff: Sounds like a flap issue. Could be the fresh air flap has malfunctioned or the blend / mode door. You will want to check function using a BMW scan tool. - Nick at Pelican Parts  
Dadog6575 Comments: I have a 323ci convertible, my air blows cold up top with all 3 blue dots, however, I have hot air on the floor, and no defroster in front. I was thinking Heater control valve sticking, Any help? Thanks in advance love this site.
Butch
June 2, 2016
  Followup from the Pelican Staff: First check if the fresh air flap is closing. If so, check if there is hot coolant getting to the heater core when the a/c is on. if so, the valve may be faulty, as it should be blocking flow. - Nick at Pelican Parts  
GEE Comments: Got a 02 BMW 525i ...when AC is on cold air only comes out of the center and side vents of driver side ...the left sides blow out hot air ..is the problem with the water heater control valve ... AC system has been completely charged
May 29, 2016
  Followup from the Pelican Staff: Usually this issue has to do with a low refrigerant charge. If you are certain it is charged correctly, there may be a blend or mode door issue. Check the system for fault codes. - Nick at Pelican Parts  
jay Comments: would the restriction be in the heater core since both the thermostat and water pump were changed in the past year? thanks again
May 28, 2016
  Followup from the Pelican Staff: hard to say. You will have to check. You can test system pressure to confirm the pump is good. Should be about 6 psi. - Nick at Pelican Parts  
jay Comments: during the winter my car would blow cold air on idle and when driving or when the revs transmission in park are high I have perfect heat, now when i turn the ac on it has recently been serviced/refilled with freon, no leaks, I get cold air on the driver side, cool air on the passenger side, when i change to feet position it is the same as well as when changed to top position, would changing the heater valve solve my problem as others have mentioned? thanks for the help
May 22, 2016
  Followup from the Pelican Staff: Sounds like poor coolant flow. Either a faulty water pump, thermostat or a restriction. - Nick at Pelican Parts  
Vedran Comments: My car is E46 318d 2003y, my problem is that when is climate active, I have cold air only on the left side of the vents, right side is not cold air. Please help! Thanks
April 4, 2016
  Followup from the Pelican Staff: SOunds like a low refrigerant charge. What are the system pressure when the problem is present? - Nick at Pelican Parts  
Shawn G Comments: I have a 1999 323I BMW i has no heat the coolant temperature is normal I bleed it about 4 times and the temperature gauge does not fluctuate how do i text temperature control valve is working properly
March 4, 2016
  Followup from the Pelican Staff: The heater valve controls the flow of hot engine coolant to the heater core. The valve is comprised of hose fitting and an electric solenoid that blocks or allows engine coolant flow. If the electric solenoid in the valve fails, it blocks coolant flow so that you get very little to no heat inside the passenger compartment. A quick check is to warm the vehicle up and then turn the heat ON; both heater hoses should be hot to the touch. If one hose is cool and the other is hot the solenoid is not allowing coolant flow. You could also have a bad signal to the valve; it is a two-wire circuit. Using a wiring diagram, you can identify the ground and battery positive feed to the solenoid, and test for proper voltage when the heat is ON.
http://www.pelicanparts.com/BMW/techarticles/BMW-3-Series-E46/113-WATER-Heater_Valve_Replacement/113-WATER-Heater_Valve_Replacement.htm - Nick at Pelican Parts
 
Levi Comments: '02 330Ci automatic. I have no heat in the cabin, all the air blows cold. When I dial 3 red dots, it seems like the air flow mostly stops but I can still hear the blower running. Just replaced the expansion tank and bled the system but still no heat. Upper radiator hose gets hot, and return line to expansion tank seems hot, but the HCV hoses are still cold. I can hear the HCV operate when I plug/unplug it. Is this a clogged HCV or heater core?
January 15, 2016
  Followup from the Pelican Staff: If there is hot coolant to the heater control valve, and to the heater core, but not out of the heater core, the heater core is likely plugged. If only hot to the valve and not out of it, the valve is restricted. - Nick at Pelican Parts  
Mike Comments: I have a 2003 335i. The cabin air is cold until I drive car. Does not matter how long I let idle to warm up it still is blowing cold air into cabin until I drive the car. Replaced thermostat and engine is at normal operating temp and still cold air until driven. When driving heater work like it should. Just initial cold start the heater will not blow hot air.
January 7, 2016
  Followup from the Pelican Staff: When the heater is blowing cold, are the hoses leading into the heater core hot? If they are hot going in and cold going out, you could have a restricted heater core. If they are not hot, the heater control valve may be faulty. - Nick at Pelican Parts  
retnug Comments: Nick, Wouldn't a faulty water pump show up as the car overheating?
January 4, 2016
  Followup from the Pelican Staff: Yes, or a major leak. - Nick at Pelican Parts  
retnug Comments: I have a 1999 323. My symptoms are: No heat when sitting at idle. If I raise the rpms I get heat. When driving I get great heat. Hot enough to get my toes pretty toasty. Will replacing the heater valve fix this. Why would there be heat when the rpms go up?
January 2, 2016
  Followup from the Pelican Staff: I would assume not, if you have heat. The RPM increase indicates either a faulty water pump or restricted heater core. - Nick at Pelican Parts  
Harry Comments: Hello, I have a 1999 bmw 328i e46. When my car is on idle, the heat starts blowing cold from the vents. Can this problem be related with the heater control valve? I know I need a thermostat as well because my temperature gauge fluctuates between the 1/3 and 1/2 mark. Thanks.
December 9, 2015
  Followup from the Pelican Staff: If heat is normal when driving, the issue may be a restriction in the heater core / hoses or a faulty water pump. - Nick at Pelican Parts  
Joe Comments: I have 2004 bmw 325ci, my radiator light turns on when I turn on the heater or defroster. When I turn the heater off, the radiator light turns off 30 seconds later. Also, there is a slight radiator leak on I noticed on my driveway but I can't find where it is coming from. By the way, my car is NOT overheating. What could this be?
November 30, 2015
  Followup from the Pelican Staff: The wiring for the level sensor may be damaged, causing an intermittent light. - Nick at Pelican Parts  
Andy Comments: My car is a 2001 325i. I did a complete cooling system overhaul: hoses, thermostat, expansion tank, water pump, as well as a new water valve. I am getting a "25: IHKA: Auxiliary water pump" error. I refilled and bled the system properly and I am also getting heat from the heater. Any idea what this could be? Thanks for your input.
November 2, 2015
  Followup from the Pelican Staff: That is for the small Auxiliary pump, if equipped. Usually mounted near the heater control valve. - Nick at Pelican Parts  
AFP Comments: I have a 2003 330i. The problem I have is that the A/C works great from a cold start. If I run the car A/C working great then park the car -say to go to the grocery store, come back out in a fairly short amount of time, hot air out of the vents. I have tested the A/C system when this is happening. The compressor is engaged, the manifold gages read near perfect pressures, the low side line is cold and condensating, high side line is hot. Could this be the HCV stuck open allowing water to flow to the heater core? How can I test this? If not, what other suggestions do you have?
August 9, 2015
  Followup from the Pelican Staff: If the line is cold, you should have cooling. What are the system pressures when it is cooling and when it stops cooling? - Nick at Pelican Parts  
Scoty Comments: Hi,

As several others have mentioned here, my problem is quite specific: heat from windscreen vents and footwell vents, but only cold or very lukewarm air from the middle vents, both central and side. Starting on the coldest setting 16C, the middle vents will slowly warm up to about 21C, then setting a warmer temp than that, the vents will noticeably drop off cold. If you select the middle vents only button it'll then seem to warm up, presumably on the strength of the hot windscreen and footwell heating.

Would this be a water heater problem possibly? BTW the middle wheel works and is set to hot when trying this.
July 29, 2015
  Followup from the Pelican Staff: You didn't mention what vehicle you have. The issue could be a blend door, or possible normal function if the center vents deliver fresh air. - Nick at Pelican Parts  
komarec Comments: when i turn on the cooling on the climatronic i get cold air just in the middle .. up in the windshiel and in my legs i get hot air.
May 27, 2015
  Followup from the Pelican Staff: I would run a mode / blend door test using a BMW scan tool. You may have a heater housing motor failure. - Nick at Pelican Parts  
komarec Comments: I have a problem with My AC System Bmw 320 E46 .When will join AC climate blowing cold 16 appears next problems.Up the windshield blowing hot air, mid blowing cold air, and down the legs blowing hot air.every response would I used Thanks in advance
May 25, 2015
  Followup from the Pelican Staff: I don't understand your question. If you only have cold air on the windshield, the issue may be a low charge. As you get fresh air from the windshield vents. Or a possible stuck open heater valve. - Nick at Pelican Parts  
JLH Comments: I believe my Valve is bad but before I change I wanted to know if the Coolant Temp Sensor on the lower hose could cause my heat not to work. If so I might replace that first. How would I know if that is faulty?
January 21, 2015
  Followup from the Pelican Staff: The radiator outlet temp sensor will not cause the heat to not work. Check if the valve is functioning first. - Nick at Pelican Parts  
JLH Comments: I just replaced, Exp Tank/atf therm/therm/waterpump/belts/ up-lo hoses. I drained coolant not fully as I did not mess with drain plug on engine and bleed after adding 1.5 gal of coolant. So I would prefer not to repeat to change this out. Can I just drain what in the radiator and perform the procedure? my blower works/car temp is 12oclock/outside temp works Prior to above upgrades heat worked it was just sporadic on either being too hot or not hot enough. Would you believe it is the Heater Valve? and do I have to completely drain the coolant? Thanks
January 20, 2015
  Followup from the Pelican Staff: Just drain the radiator a bit. You can also clamp off the hoses to the valve to prevent coolant from leaking. Be sure there is no pressure in the system when you start. - Nick at Pelican Parts  
JLL Comments: 01 325i - Do I have to completely Drain the coolant in order to complete a replacement of this unit. Or can I just drain the radiator without messing with the plugs etc.. Thanks
January 19, 2015
  Followup from the Pelican Staff: Just drain the radiator a bit. You can also clamp off the hoses to the valve to prevent coolant from leaking. Be sure there is no pressure in the system when you start. - Nick at Pelican Parts  
J. Comments: yes, it does get better when the engine rpm is raised with the transmission in park, and the engine warms up perfectly fine.
January 3, 2015
  Followup from the Pelican Staff: Sounds like a faulty water pump. - Nick at Pelican Parts  
J. Comments: My car is a 1999 BMW 323i, on idle the heat isn't warm, but when driving it is, could this solve my problem? Thanks for your help.
December 31, 2014
  Followup from the Pelican Staff: If you raise the engine rpm with the transmission in park, does the heat get better? Does your engine warm up normally? - Nick at Pelican Parts  
Speedy-Gungolis Comments: My car is a 2002 BMW 325Xi. The heat works perfectly through the defrost vents, but when switched to the dashboard and lower vents, only cold air comes out. Could this be related to the Heater Valve? Thanks for your expertise.
February 17, 2014
  Followup from the Pelican Staff: I would think no, if there is any heat making it into the cabin, the valve is likely working. Look for a problem with the mode doors.- Nick at Pelican Parts  

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