Lennox · humidifier · whole house bypass

Lennox HCWB3-17 replacement filter

Use part X2661. Replace annually or if performance drops.

The filter that fits

Maker lists this model

Lennox X2661 (#35) water panel

Healthy Climate #35 Replacement Humidifier Water Panel

Part number: X2661
How many: 1 per unit
How often: Replace annually or if performance drops
Size: 10 x 13 x 1-3/4 in

Buy X2661 (#35) water panel on Amazon Manufacturer page

Opens an Amazon search for Lennox X2661 (#35) water panel. Check the listing says X2661.

See the sources

Does your exact model share this filter?

Lennox labels several versions of the HCWB3-17. Check the label on your unit.

HCWB3-17 takes X2661
HCWB3-17A same filter
HCWB3-17K same filter
HCWB3-17AK same filter
HCWB17 not confirmed by Lennox · Current model name; lennox.com's HCWB17 page links the HCWB3 manual

Look-alike models that take a different filter

The smaller HCWB3-12 takes the #10 panel X2660.

Sources

High confidence: the manufacturer names this exact model on a live page. Each line is the page we read and the day we read it.

Which filter fits lennoxpros.com Maker's own page checked Oct 1, 2026
Lennox X2661, Healthy Climate #35 Humidifier Water Panel ... Replacement Humidifier Pad for Healthy Climate Humidifiers: HCWB2-17, HCBW2-17A, HCWB3-17, HCBW3-17A, HCWP2-18, HCWP2-18A, HCWP3-18, HCWP3-18A
How many lennox.com Maker's own page checked Oct 1, 2026
Lennox Healthy Climate humidifier operating manual (form 10009367, 04/2011; covers HCWB3-12, -12K, -12A, -12AK, HCWB3-17, -17K, -17A, -17AK, HCWP3-18 and HCWP3-18A), linked from lennox.com's current HCWB17 and HCWP18 pages, maintenance steps slide the single humidifier pad out of the scale control insert and insert a new one
How often lennox.com Maker's own page checked Oct 1, 2026
Lennox Healthy Climate humidifier operating manual (form 10009367, 04/2011; covers HCWB3-12, -12K, -12A, -12AK, HCWB3-17, -17K, -17A, -17AK, HCWP3-18 and HCWP3-18A), linked from lennox.com's current HCWB17 and HCWP18 pages, PDF p4: 'For best performance, you should replace the humidifier pad in your humidifier at least annually' ... 'Replace Humidifier Pad annually or if performance drops'
Size lennoxpros.com Maker's own page checked Oct 1, 2026
Additional Information 10" W x 13" H x 1-3/4" D

Show all 7 sources

Which filter fits

lennoxpros.com Maker's own page checked Oct 1, 2026
Lennox X2661, Healthy Climate #35 Humidifier Water Panel ... Replacement Humidifier Pad for Healthy Climate Humidifiers: HCWB2-17, HCBW2-17A, HCWB3-17, HCBW3-17A, HCWP2-18, HCWP2-18A, HCWP3-18, HCWP3-18A
lennox.com Maker's own page checked Oct 1, 2026
Lennox Healthy Climate humidifier operating manual (form 10009367, 04/2011; covers HCWB3-12, -12K, -12A, -12AK, HCWB3-17, -17K, -17A, -17AK, HCWP3-18 and HCWP3-18A), linked from lennox.com's current HCWB17 and HCWP18 pages, PDF p4: 'Replace Humidifier Pad annually or if performance drops (Catalog No. X2660 for Models HCWB3-12, HCWB3-12K, HCWB3-12A and HCWB3-12AK, and Catalog No. X2661 for Models HCWB3-17, HCWB3-17K, HCWB3-17A and HCWB3-17AK)'
lennox.com Maker's own page checked Oct 1, 2026
Lennox Healthy Climate humidifier operating manual (form 10009367, 04/2011; covers HCWB3-12, -12K, -12A, -12AK, HCWB3-17, -17K, -17A, -17AK, HCWP3-18 and HCWP3-18A), linked from lennox.com's current HCWB17 and HCWP18 pages, PDF p4 (Required Maintenance, HCWB3 models): 'Turn the integral bypass damper (3) to the SUMMER position'
lennox.com Maker's own page checked Oct 1, 2026
Lennox Healthy Climate humidifier operating manual (form 10009367, 04/2011; covers HCWB3-12, -12K, -12A, -12AK, HCWB3-17, -17K, -17A, -17AK, HCWP3-18 and HCWP3-18A), linked from lennox.com's current HCWB17 and HCWP18 pages, PDF p5 (power humidifier maintenance, unit with power cord): 'Replace humidifier pad annually or if performance of the humidifier drops. (Catalog No. X2661)'

How many

lennox.com Maker's own page checked Oct 1, 2026
Lennox Healthy Climate humidifier operating manual (form 10009367, 04/2011; covers HCWB3-12, -12K, -12A, -12AK, HCWB3-17, -17K, -17A, -17AK, HCWP3-18 and HCWP3-18A), linked from lennox.com's current HCWB17 and HCWP18 pages, maintenance steps slide the single humidifier pad out of the scale control insert and insert a new one

How often

lennox.com Maker's own page checked Oct 1, 2026
Lennox Healthy Climate humidifier operating manual (form 10009367, 04/2011; covers HCWB3-12, -12K, -12A, -12AK, HCWB3-17, -17K, -17A, -17AK, HCWP3-18 and HCWP3-18A), linked from lennox.com's current HCWB17 and HCWP18 pages, PDF p4: 'For best performance, you should replace the humidifier pad in your humidifier at least annually' ... 'Replace Humidifier Pad annually or if performance drops'

Size

lennoxpros.com Maker's own page checked Oct 1, 2026
Additional Information 10" W x 13" H x 1-3/4" D