Damp Musty Odor from Heating System

ralphfr · Mar 15, 2015

After very damp or rainy days I get a musty odor from the heating system when I first put it on. Anyone know of any causes for this? Do you think I might have a leak?

I posted an issue with dampness under my floor mats in the Rugged Ridge thread. Now I'm wondering if there's a connection. I don't have a sunroof.Thanks.

miketmx · Mar 16, 2015

I saw another thread somewhere that you could pull away the carpet near the gas pedal and check to see if the HVAC drain tube is blocked or working properly. Note I have never personally tried this and I got rid of a stale smell by replacing the cabin filter behind the glove box.

ralphfr · Mar 16, 2015

miketmx said:
I saw another thread somewhere that you could pull away the carpet near the gas pedal and check to see if the HVAC drain tube is blocked or working properly. Note I have never personally tried this and I got rid of a stale smell by replacing the cabin filter behind the glove box.

I will definitely look up that thread about the HVAC drain tube. I'm due for a new cabin filter. I'll try that also. Thanks for the response Mike.

OK Found it here: http://www.jeeppatriot.com/forum/showthread.php?t=107736&highlight=Drain+tube Thanks again.

O'DubhGhaill · Mar 16, 2015

Interestingly, after running my Pat these past few weeks in ~0 to 20F temps, I experienced the usual interior window fogging problem that my wife's Pat had last winter when we used hers quite a bit. I ran the defroster every time I ran the Pat, often at full power. Then, as it warmed up to below 32F, I noticed a musty, almost fish-like smell from the defroster and heater when first running it. Eventually the smell dissipated and I haven't noticed it lately at all, the tepid collected water probably made its way out via this tube? Is it true that running the defroster is actually running the AC?

Anyways, these Pats have a serious interior fogging/frosting issue in below 20F temps., especially with two little ones and the wife along for a ride.

ralphfr · Mar 16, 2015

O'DubhGhaill said:
Interestingly, after running my Pat these past few weeks in ~0 to 20F temps, I experienced the usual interior window fogging problem that my wife's Pat had last winter when we used hers quite a bit. I ran the defroster every time I ran the Pat, often at full power. Then, as it warmed up to below 32F, I noticed a musty, almost fish-like smell from the defroster and heater when first running it. Eventually the smell dissipated and I haven't noticed it lately at all, the tepid collected water probably made its way out via this tube? Is it true that running the defroster is actually running the AC?

Anyways, these Pats have a serious interior fogging/frosting issue in below 20F temps., especially with two little ones and the wife along for a ride.

Not sure about the AC running when defroster is on. If my defroster is on the AC light is off unless I put it on. Doesn't mean it doesn't come on though. I would like to know if there is a connection also. I'm going to check the tach to see if there is any change when putting on the AC w/o defrost and then try the defroster only and see if there is any difference.

Metaxa · Mar 16, 2015

All modern vehicles with AC run the condenser when you have the HVAC controls in defrost or defrost blend.

This is to remove moisture from the interior air.

The funky smell is from the condenser defrosting into the HVAC system and the moisture just sitting there. In future you want to turn your air con off a bit out from home so it defrosts and drips to the road. You also want to ensure the drain is clear.

They sell tablets that kill and deodorize your HVAC pan in home stores. They are designed for dehumidifiers. Additionally they sell cleaner/deodorizer sprays in any good auto parts store. Basically you set your AC to settings on the can and spray it into the intake which is under the hood, on top of the firewall passenger side.

Holding dog(s) inside cars is one real good way to get them full of moisture. So is never opening any windows on long, longish, longer drives. So is keeping your HVAC settings on recirq all the time.

Use it or lose it...I run my air conditioning full on at least twice a month in the winter. except I turn the temp to heat. Keep it exercised and clear and it won't smell.

Park it frozen up, never use it all winter, don't clear the drain tube if it needs (I've never had to do that and I live in mold, mildew capitol of the country...our climate zone is called temperate rain forest.)

Heirio · Mar 17, 2015

Defrosters use ac by default because it is the quickest way to get the glass on the interior to match the temp on the outside. If you run the heater on full blast it will take forever because it has to heat the glass on both sides to the same temp. If it is cold enough and the heat is blasting full gas enough enough there is a risk of cracking the glass. I find that start it with the ac when you start the vehicle. After a couple mins turn off the ac and just blow outside air and let it warm slowly to minimize fog and keep the cracking risk at a minimum.

Damp Musty Odor from Heating System

ralphfr

miketmx

ralphfr

O'DubhGhaill

ralphfr

Metaxa

Heirio

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