DEWALT 20V MAX 1/2 Gallon Wet/Dry Portable Vac (DCV517B): problems, parts and running costs

Checked: 2026-10-05

Summary

The owner evidence on this vac is small and negative in kind: two reports on the retailer review pool describe the unit losing power entirely, one of them after a little over a year with a blown fuse on the battery-controller board that nobody could source a replacement for. DEWALT publishes an exploded diagram but no spare-parts catalog for the filters, hose or power head, so an electronics failure ends as a warranty claim rather than a repair. Running costs are near zero and cannot be pinned down in dollars: the two filters are washable, no runtime figure is published and no filter or battery prices were found, so there is nothing to compute a yearly total from. It is a good buy only if you already own 20V MAX packs, and only at $120 or less for the bare tool, since the same dealers sell larger corded wet/dry vacs at or below what this one costs.

Common problems and fixes

The unit stops working at all — the clearest exact-model complaint. One owner reports that both of two 20V MAX hand-held units they bought stopped working, while describing themselves as a large DEWALT tool owner, which points at the vacuum rather than at the packs. Two reports are not a failure rate, but they are the reason to check the return window and keep the receipt. DEWALT covers this with a 3-year limited warranty, 1 year of free service and a 90-day satisfaction guarantee; DEWALT’s published reply to the reviews is a support-ticket address rather than a parts offer. [1][2][3]
Electronics failure with no service path — the second report from the same pool says the unit worked great for a little over a year and then quit, with the cause identified as a blown fuse on the battery-controller PCB and no replacement findable online. DEWALT publishes an exploded diagram for the DCV517B but no orderable part for the board, the filters, the hose or the power head, so a failure after the warranty period leaves a dead tool. Make the claim inside the first year of service, and expect the warranty rather than a part to be the route back. [1][2][3]
Airflow restricted where the hose enters the tank — the recurring complaint in owner discussion about DEWALT cordless wet/dry vacs, with one poster calling them one of the worst 20v vacuums on the market. That thread does not consistently name a model and may cover the larger DCV580H and DCV581H, so treat it as a brand-family caution: check the hose entry for a compacted plug after every wet job, and empty dry debris before switching to wet pickup, which is what the manual asks for anyway. [4][3]
Short runtime, and DEWALT never says how short — the product page and the manual claim only that the vac runs off all 20V MAX packs “for long run-time”, with no number, and the same owner thread calls these vacs energy hungry and recommends a 5 Ah pack as a minimum. If you size a job against a runtime figure from a dealer page, you are guessing. Bring a spare pack instead. [1][3][4]
Filter cleaning has limits the manual enforces — cleaning means shaking off excess dust and tapping the filter into a bin, with a water rinse not always required; a brush or compressed air is forbidden. The secondary filter has to stay installed unless it is the one being cleaned, and the unit must never be run with the filters out. Rinse the wet/dry filter after wet jobs and let it dry fully, or airflow drops. [3]
Too small for anything heavy — the 0.5 gallon tank and 1-1/4 in hose are a small-jobsite design. The retailer roll-up describes the vac as good for small cleanups and light debris, and DEWALT’s own intended uses are general cleanup, cabinet cleanout, drywall and masonry cleanup and water cleanup. For grit, plaster dust in volume or a flooded room, step up a capacity. [2][1][7]
The dealer specs contradict each other — airflow is listed as 40 CFM by one dealer and 105 CFM by another on the battery-bundled variant, weight ranges from 3.8 lb on DEWALT’s own specification block to 4.95 lb at one dealer, and two dealers directly contradict each other on whether the tool has a blower. DEWALT publishes no airflow, no dimensions and no runtime. Ignore any single spec sheet for this vac. [7][8][5][6][1]

Parts and consumables

Wet/dry filter (no part number found) — the high-efficiency wet/dry filter twists off the power head for cleaning. DEWALT describes it as washable by tap or water rinse and claims the Gore version traps 99.97% of dust at 0.3 microns, a manufacturer claim with no published test behind it. The manual says to use only genuine DEWALT replacement filters if it becomes clogged beyond cleaning, damaged or fails, but no filter part number and no price were found in this research. [1][3]
Secondary filter (no part number found) — the second filter in the unit. It must stay in place whenever the vac runs, and no replacement part number or price was found. [3]
20V MAX battery pack and charger — not in the box, so this is the real cost for anyone starting from nothing. Any 20V MAX pack works; owner discussion suggests at least a 5 Ah pack because these vacs are power-hungry. Reference points from retailer bundles in October 2026: the DCV517BW230 with one 3.0 Ah battery listed at $298.00, and the DCV517BWCB200-4 with four 3.0 Ah packs listed at $328.00. Battery and charger prices sold on their own were not captured. [1][4][10][11]
Hose, hose connector and nozzles — the hose measures 1-1/4 in by 2.5 ft and ships attached; DEWALT lists the unit as a single piece. No replacement part number or price was found for the hose or the nozzles. [5][7]

Yearly running cost

Not enough data to put a dollar figure on it. The consumables are the two filters and the battery packs, and none of them has a published price in this research: no filter part number, no filter price, no battery price and no charger price were found, so a replacement schedule cannot be turned into a yearly total. The filters are designed to be washed rather than discarded, which keeps the recurring cost near zero if you do that. Electricity cannot be computed either, because DEWALT publishes no runtime figure and no independent test measured one, so there is no watt-hour count to charge per year. Treat the yearly running cost as zero and treat battery packs as a purchase you price when you need one. [1][3][4]

When it is a good buy

The bare tool clustered at $159.00 to $169.00 across US dealer listings in October 2026: $169.00 at Northern Tool, L&M Supply, Acme Tools, Factory Authorized Outlet and The Isens, $165.00 at Coastal Tool, and $159.00 at Preston Hardware. The higher numbers on the street are procurement listings rather than consumer value signals: Farm and Home Supply listed $249.99 and stopped shipping to California, and Motion listed $267.42 each. [6][7][9][12][15][13][14][16][17]

$120 or less for the bare tool: defensible for someone who already owns 20V MAX packs and needs a half-gallon wet/dry unit for spills and light debris.
$121 to $169, which is where the bare tool actually sits: weak. There is no instrumented test, no published runtime, no parts channel, and two owner reports of total power loss.
Above $170: not justified on any of the evidence found.

If you have no packs, price the all-in number before committing: the two retailer bundles with one and four 3.0 Ah packs listed at $298.00 and $328.00 in October 2026, and The Isens ran a free-battery offer with select bare tool purchases. Compare that all-in figure against a larger corded 2-gallon wet/dry vac from the same dealer, because at these shelves those cost the same or less.

DEWALT DCV517M1 kit — the same vac with a DCB204 4 Ah battery and DCB115 charger included, which removes the extra spend for anyone without 20V MAX packs. It was listed at CAD $294.99 at Atlas Machinery in Canada when checked. The better pick when the batteries do not already exist. [18]
DEWALT DCV580H or DCV581H — the 2-gallon corded-capable wet/dry vacs in the same DEWALT line, sold by the same dealers at or above the DCV517B price. The better pick when you need real capacity, a blower, or runtime you can size a job against. [6][7]
A corded 2-gallon wet/dry vac from the same dealer — the honest alternative for someone who does not own DEWALT batteries. The same dealers list these at or below the DCV517B bare-tool price, which is the central value problem with this tool. [6][7]