How Long the Hose Behind the Dryer Should Be

The Florida Rule for the Hose Behind the Dryer

The flexible piece between the back of the dryer and the duct collar in the wall has a name in the code: the transition duct. Section M1502.4.3 of the 2023 Florida Building Code, Residential, gives it three conditions. It is a single length, listed and labeled to UL 2158A, the safety standard for dryer transition duct. It is no longer than 8 feet. And it is never concealed within construction, which means not inside a wall, floor, ceiling or a closed cabinet.

That is the whole of the code's hose rule, and each part has a reason. One piece means no extra joints for lint to catch on. The length cap keeps a soft, ribbed hose from becoming the main duct. Staying in view means you can see when it is crushed or pulled off.

What the Dryer Makers Allow

Your dryer's own installation instructions may be stricter, and they are the ones the dryer was tested against. Maytag says flexible metal vent should not exceed 7 3/4 feet in total and must be fully extended and supported in the dryer's final position. Samsung caps flexible metal duct at 7 feet 10 1/2 inches. GE says to use the shortest length possible and stretch it to its full length.

Maytag adds a detail that surprises people. The Florida code does not count the transition hose in its 35 foot duct budget, which is measured from where the hose connects to the fixed duct. Maytag's vent chart does count it: the hose length is subtracted from the allowed run. So a long hose behind a Maytag dryer shortens the duct you can have in the wall.

Sizing and Cutting a Hose to Fit

The right hose is long enough to let the dryer sit in place without the hose being pulled taut, and short enough that nothing coils or sags behind the machine. Maytag asks you to remove the excess to avoid sagging and kinking. Here is a practical way to get there:

• Set the dryer in its final position, leaving the clearance its manual asks for behind it.
• Measure the path from the dryer outlet to the wall collar, following the route the hose will take with gentle curves.
• Add only enough to slide the hose fully over both collars.
• Cut the hose square with snips, and smooth any sharp edge so it cannot tear or snag lint.
• Fit it, push the dryer back slowly and check from the side that nothing has folded.

Why Two Hoses Are Never Joined

When a dryer moves farther from the wall, the quick fix is a second hose joined to the first. The Florida code's single-length rule rules that out, and for good reason. The joint between two ribbed hoses is a lip inside the airflow where lint collects, and the extra length doubles the chance of a kink or crush behind the machine. Two hoses also put the run past what the dryer makers allow.

The same thinking applies to hiding a hose. A hose run through a wall to reach a duct further away breaks the not-concealed rule, and GE's instructions say never to use transition duct inside a wall, floor or ceiling. If the dryer needs more reach, the fixed metal duct moves closer, which is covered in how to move a dryer vent.

Which Hose Material Counts as Listed

The Consumer Product Safety Commission advises replacing plastic or foil accordion ducting with rigid or corrugated semi-rigid metal duct, because the flexible plastic and foil kinds trap lint more easily and crush more easily. Samsung allows a foil-type flexible duct only when the dryer maker specifically identifies it and it complies with UL 2158A, and it warns that flexible materials are known to collapse and trap lint. A white vinyl hose is never acceptable. Look for the UL 2158A marking on the package or the hose itself; if you cannot find one, treat the hose as unlisted.

When the Hose Is Telling You Something

A hose that keeps coming off, flattens every time the dryer is pushed back, or fills with lint between cleanings is a sign that the dryer and the wall collar are in the wrong places relative to each other, or that the duct beyond the wall is too long. How the hose ends are fastened is its own subject, covered in how to connect dryer vent hose, and whether tape or screws belong on it is answered in can you duct tape dryer vent hose.

We replace hoses and fix the run behind them as part of dryer vent repair. We are family-owned and local, with an experienced crew and a Proudly American way of doing business: a free inspection first, then a written estimate.