is this the reason why my furnace smell there is a gap? My furnace is in a small enclose room with drywall carry a little gap.

I am not sure exactly where this gap is? A furnace should not smell, at least not that bad. I don't think this product would stop that, but at the price worth a try. My suggestion is to try it & see if it works, but still contact a furnace specialist to make sure your furnace is working correctly. You also did not note if oil or gas fired, or heat pump? A heat pump should not smell at all, anytime! So more checking needs to be done, I think, for your safety.

My furnace filter opening (just wider than the 1 inch filter) is recessed between the furnace and the insulation covered ductwork. Will this work?

It uses magnets to hold in place. If your duct is covered in insulation board, the magnets won’t work. They would only stick to the metal of the duct or to the metal furnace enclosure. Probably won’t work for you.

Are furnaces required by health and safety code to have a cover on the filter slot?

I don’t think they are required or if they are that depends on the state and city or institution . Although the cleaner the filtered air is , the better quality will be

It’s advertised that each piece is 25” long but I’ve seen some people say that each piece is only “14 can anyone confirm?

Each piece is 14" and comes with 2 pieces per package. You can also overlap the pieces on your furnace to fit various sizes.

Filterlock Furnace Filter Slot Seal Magnetic Seal Cover For Any

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Fully operational. Shipping worldwide, on schedule.Duty & taxes paid at delivery

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$34.14

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Description

🛠️ Lock in Fresh Air, Lock Out Waste – The Magnetic HVAC Upgrade You Can’t Afford to Miss!

INSTALL IN A SNAP - Universal fit for any 1” furnace filter up to 25” long with effortless magnetic attachment.
CUT COSTS NOT COMFORT - Reduces HVAC energy waste, lowering your utility bills while boosting system efficiency.
BUILT TO LAST EASY TO USE - Reusable fiberglass design that’s easy on/off for long-term, hassle-free protection.
BREATHE CLEANER LIVE BETTER - Blocks allergens, dust, and harmful gases from bypassing your filter for superior indoor air quality.
SEAL THE DEAL WITH MAGNETISM - Patented two-piece magnetic system locks in air, eliminating costly leaks.

The FilterLock Furnace Filter Slot Seal is a patented, magnetic two-piece cover designed to fit any 1” furnace filter up to 25” long. It effectively eliminates air leaks at the filter slot, improving indoor air quality by preventing contaminants from bypassing the filter. This energy-efficient solution reduces HVAC energy consumption and utility bills. Made from durable fiberglass, it offers easy, reusable installation with a universal fit, making it a smart upgrade for any modern HVAC system.

Specifications

ASIN	B00PKS6MT0
Best Sellers Rank	#7,661 in Tools & Home Improvement ( See Top 100 in Tools & Home Improvement ) #111 in Furnace Filters
Brand	AllergyZone
Brand Name	AllergyZone
Compatible Material	Metal
Customer Reviews	4.4 out of 5 stars 3,212 Reviews
Global Trade Identification Number	00855118000257
Item Dimensions	25 x 4.8 x 0.1 inches
Item Form	Solid
Item Weight	0.13 Pounds
Item dimensions L x W x H	25 x 4.8 x 0.1 inches
Manufacturer	AllergyZone, LLC
Material	Fiberglass
Material Type	Fiberglass
Model	AZFL-100
Number of Items	1
Part Number	AZFL-100
UPC	855118000257 013964070460 826719862223
Unit Count	1.0 Count

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