ResMed CPAP Dry Mouth Fix: Humidification and Mask Solutions

Quick Answer

Dry mouth is the number one comfort complaint among ResMed AirSense users and is the leading cause of CPAP non-compliance. There are two distinct causes: insufficient humidification and mouth breathing. If you use a nasal mask or nasal pillows, your mouth opening during sleep allows the humidified air to escape before reaching your lungs, drying out your mouth and throat. The fix depends on the cause: increase the HumidAir humidity level to 5-6, ensure the humidifier is actually heating (check contact pins), and if you are a mouth breather, either add a chin strap to keep your mouth closed or switch to a full-face mask that covers both nose and mouth.

ResmedCpapSeverity: low90% DIY Success

Time to Fix

2–10 min

Difficulty

beginner

Parts Cost

$0 – $0

Tools Needed

Isopropyl alcohol wipes, Cotton swabs

What Does the DRY-MOUTH Code Mean?

CPAP dry mouth is caused by low humidification or mouth breathing with a nasal mask. Increase humidity to level 5-6, verify the humidifier is heating, and consider a chin strap or full-face mask.

Most Likely Causes

Based on aggregated repair data, here is the probability breakdown for this error code:

Mouth breathing with a nasal mask or nasal pillows40%

Humidification level set too low24%

Humidifier not heating due to dirty contacts14%

Climate Control set to Off12%

Water chamber empty (ran out during the night)10%

Symptoms You May Notice

Dry mouth upon waking
Sore or scratchy throat in the morning
Cracked or chapped lips
Bad breath after therapy
Waking with mouth open
Excessive thirst during the night

Can you reset a Resmed cpap to clear the DRY-MOUTH code?

AirSense 10: Settings > Device > Reset Device restores Climate Control to defaults. AirSense 11: My Device > Factory Reset. After resetting, manually set humidity to level 5-6.

Tools Required for Diagnosis

Isopropyl alcohol wipesCotton swabsDistilled water

Diagnostic Checklist

Follow these steps in order. We start with the easiest external fixes before opening up the machine.

Determine if you are mouth breathing

Determine if you are mouth breathing. When you wake with dry mouth, note whether your mouth was open. Ask a bed partner to observe, or place a small piece of surgical tape vertically on your lips before sleep (mouth taping) to test whether keeping the mouth closed resolves the dryness.

Increase the HumidAir humidity level

Verify the humidifier is working

If humidity is maxed and the humidifier is working but dry mouth

Replacement Parts

If your diagnostic testing proves the component has failed, you will need a replacement. We recommend OEM parts over aftermarket for water-handling components.

Part Name	OEM Number	Estimated Price
ResMed CPAP chin strapN/A · $0–$0	N/A	$0 – $0
ResMed full-face mask (if switching from nasal)N/A · $0–$0	N/A	$0 – $0
ResMed ClimateLineAir Heated TubingN/A · $0–$0	N/A	$0 – $0
ResMed HumidAir Water ChamberN/A · $0–$0	N/A	$0 – $0

Verify part fitment for your Resmed model

Repair vs. Replace Calculator

Appliance Age (Years)7 Yrs

Labor Approach

Our Verdict

REPLACE

Estimated Cost: $0 (Parts) vs $800 (New Machine)

Frequently Asked Questions

Should I use a chin strap or switch to a full-face mask?

Try a chin strap first since it is cheaper ($10-20) and works for mild mouth breathing. If you are a heavy mouth breather or the chin strap is uncomfortable, a full-face mask is the definitive solution because it delivers air to both the nose and mouth. Ask your DME provider for a mask fitting.

Can dry mouth from CPAP cause dental problems?

Yes. Chronic dry mouth reduces saliva flow, which increases the risk of cavities, gum disease, and oral infections. Saliva is a natural antimicrobial and remineralizer for tooth enamel. If you experience persistent CPAP dry mouth, address it promptly and mention it to your dentist.

What humidity level should I use to prevent dry mouth?

Most users who experience dry mouth need humidity level 5-6 on the HumidAir scale of 1-8. Start at 5 and increase if needed. If you live in a particularly dry climate (desert Southwest, heated homes in winter), you may need level 7-8 combined with heated tubing to maintain moisture to the mask.

Related Resmed Cpap Error Codes

Code: HUBResMed CPAP Error Codes: Complete AirSense 10 and 11 Fault Guide Code: HUMID-FAULTResMed CPAP Humidifier Not Working Code: HIGH-LEAKResMed CPAP High Leak Detected Code: PROBLEMSResMed CPAP Common Problems and How to Fix Them

Models Known to Experience DRY-MOUTH Errors

This repair applies to most Resmed cpaps with this error code. Common model numbers include:

AirSense 10 AutoSet, AirSense 10 CPAP, AirSense 10 Elite, AirSense 10 For Her, AirSense 11 AutoSet, AirCurve 10 VAuto, AirCurve 10 ST

Last verified for technical accuracy on March 15, 2026