ECHO 4 gal. Diaphragm Backpack Sprayer-MS-401 - The Home Depot


Model # MS-401

Internet # 204631895

Store SKU # 1000025872

4 gal. Diaphragm Backpack Sprayer

ECHO 4 gal. Diaphragm Backpack Sprayer

This item has been discontinued.
The Home Depot no longer carries this specific product.

$89.97 / each


Model # MS-401

Internet # 204631895

Store SKU # 1000025872

Featuring heavy-duty, padded shoulder straps to help provide comfortable carrying. The ECHO 4-gal. Diaphragm-Pump Backpack Sprayer is designed for use with powders, liquids and water-soluble solutions. The 4 nozzles offer stream adjustment for customizable spraying and the wand can be used for left- and right-handed application.

  • Professional grade diaphragm pump equipped with Viton seals to withstand harsh chemicals, this pump is designed for use with powders, water-soluble solutions and liquids
  • Professional grade fiberglass wand and industrial grade flow control with comfort grip
  • Extra large tank opening with handle integrated into the tank cap
  • Heavy duty padded straps with waist belt
  • Ambidextrous folding pump lever and guard bar for stability

Info & Guides

You will need Adobe® Acrobat® Reader to view PDF documents. Download a free copy from the Adobe Web site.


Assembled Depth (in.)  9 in  Assembled Height (in.)  21 in 
Assembled Width (in.)  14.5 in  Hose length (in.)  48 
Product Height (in.)  21  Product Length (in.) 
Product Width (in.)  14.5 
Adjustable spray tip  Yes  Applicator type  Sprayer/Mister 
Capacity (gallons)  Returnable  90-Day 
Shoulder strap  Yes  Sprayer/mister type  Backpack 


Rated 4.5 out of 5 by 55 reviewers.
Rated 5 out of 5 by Replaced all my previous sprayer This sprayer came 95% assembled, all I had to do was attach the air pump bar and extension pipe which required a minute worth time with no tools required. This sprayer replaced all my previously owned sprayers. The container’s construction is solid and will last me few years. I find it very convenient that I can switch the pump bar for right/left handed operation. It would’ve been great if this was a hot swap without removing it from my back to switch the pump bar. Also, it would’ve been great if the pump bar had multiple angles adjustments that were changeable on the fly. It comes with only two adjustments, one for storage and one for spray. My backyard faces 10 acres of wild shrub and weeds and I have to spray my yard every spring and fall to keep it weed free. With back-pack capable, I can now spray the entire yard in a single go without taking breaks that I used to take with hand-held container. The straps that go on the shoulder are padded and provide good support for my shoulders. The waist strap helps me keep the container from wobbling during air pumps. You get three additional adaptors to change the spray pattern but I do not see myself ever using those since pre-attached nozzle works well for me. February 1, 2014
Rated 4 out of 5 by Saves time and energy, sprays well I used it to spray salt solution on my property during snow/ice and I couldn’t be more satisfied with its productivity. Once the container was on my back, there was least amount of effort I had to contribute for pre-treating my deck, driveway and front sidewalk. The shoulder strap has decent volume of padding and felt comfy on my shoulders. Some consumers say that User Manual instructions are not enough. I think User Manual is just fine, the sprayer comes almost fully assembled; you just have to plug in the pumping bar per your right/left hand use and then mount the want on the handle with no tools required. You don’t even need the user Manual for that. It came with three additional nozzles and the Manual clearly illustrates how to replace them. Couple of improvements can make this sprayer excellent; 1) Pumping bar should’ve had a better angle in Spray Mode. Instead of setting it to 90 degree, it should’ve been about 70-75 degrees max or better option would be to provide additional holes and let the consumers decide what angle they want. 2) It needs a hook or some mechanism for the wand where I can secure it to free my hands. While the sprayer is on my back and I need to use both hands for something I have to let want sit on the ground since wand’s place holder is on top of sprayer’s cap which is not reachable. February 5, 2014
Rated 5 out of 5 by The good quality, durable sprayer, in new user friendly technology. The Echo Diaphragm technology sprayer is better than the conventional piston pump, since I do not have to unload it from my back to pump air. I can go all the way until the tank is empty; just keep on pumping air occasionally, while it is still on my back, when the pressure is down. It is a heavy duty sprayer, well made , with all durable materials, and easy to carry on the back. The Diaphragm-Pump Backpack Sprayer is designed for use with powders, liquids and water-soluble solutions., but not flammables, caustics or bleach. (do diligence) The pumping handle liver can be used for left- and right-handed application. I have tested the sprayer and I am very happy with its performance. The spray is powerful, no leaks anywhere and very easy to pump and pressurize when on back. Please see my video to see the spray in action and also the diaphragm technology at the bottom of the sprayer. Thanks Echo, for the good quality and durable sprayer in a new user friendly technology. February 1, 2014
Rated 4 out of 5 by Fine sprayer, the instructions could use improvement This sprayer is comfortable to wear, and, for the most part, easy to use. I found the instructions lacking on how to change the nozzles and what the various nozzles did, so I called the help line and talked to a nice lady who explained in a matter of seconds that the "nut" that holds the adjustable nozzle to the wand is removable - just hold the adjustable nozzle in one hand and push up on the nut, wiggling to dislodge the rubber washer holding the nozzle in place. You're then left with a rubber washer and a plastic nut with a hole it in that happens to fit the other supplied nozzle plates. Assembly, in order, is wand, rubber washer, nozzle plate, and nut. The instructions also say to lubricate the rubber gaskets, but didn't say with what. An internet search suggested petroleum jelly, so that's what I used. The adjustable nozzle has a cone spray that you can vary from a stream to a medium-wide angle. The "fan" nozzle is blue and emits a wide, even spray. The nozzle plate with a single hole is a very thin stream that I was able to spray about 30 feet. The one I couldn't figure out is the last one with two holes. It sprays 2 thin streams at 160 degrees - perhaps for spraying both up and down in a stud bay. The pump handle attaches with a spring pin and can be fastened on either side and either horizontally for use or vertically for storage. The pump handle has to be worked both up and down - it doesn't spring up on its own. I used it to spray moss killer on my driveway and the clumps of moss on the roof. There are a few minor drawbacks. There a clips for the wand on the right side of the tank that wouldn't hold securely - the wand kept popping out. There is a second set of clips on top of the cap that work well. There's a plastic lock-on tab for the spray handle that was very hard to engage, but I don't plan to use it so it's not a big deal. It comes with a "lifetime" warranty that doesn't cover any of the gaskets or diaphragm. Replacement parts are available from the manufacturer and Home Depot. For the important things, being comfortable to wear, easy to pump, even spray, and emptying completely, it works very well, so I can recommend it. January 20, 2014
Rated 4 out of 5 by Great product but instructions could be improved We decided to try this diaphragm backpack sprayer as an alternative to our smaller 2.5 gallon pump sprayer. We use the sprayer for everything from spraying insecticide around the perimeter of the house to weed killer to deck sealer however it is difficult to fully clean out the deck sealer and the old piston pump sprayer’s performance has suffered as a result. Reading up online, diaphragm pumps seem to handle the soluble powders a little better than piston pumps, particularly if the powders don’t fully dissolve. Since we were spraying a soluble borax-based termite treatment and also use water seal on our deck every couple of years, we decided to switch to the diaphragm sprayer. The pump requires hardly any assembly out of the box, about 5 minutes max. The pump handle can be mounted on the left or the right side to suit left or right handed use and switching it over to the opposite side takes a few seconds as it’s held on with a single spring clip. It takes a few primes of the handle to get the pump up to pressure and is easier to keep at pressure than our smaller piston pump sprayer as its strapped to your back and therefore very stable when you’re using the priming handle. The sprayer comes with a variable nozzle that can be finger adjusted between a fine fan spray and a single jet spray. There are also three separate nozzles which are useful if you are spraying something like deck sealer, stain or water proofer as they are easier to dismantle and clean than the variable adjuster nozzle. The blue nozzle creates a ‘fan’ spray, the domed nozzle creates a fine jet spray while the dual nozzle creates two opposing jets angled at about 45 degrees. The fixed nozzles and their spray patterns can be seen in the photos attached to this review. Unfortunately the instructions don’t explain how to use the extra nozzles. Through trial and error I was able to figure out that the black adjustable spray tip has to be dismantled in order to re-use the black plastic nut that screws it onto the end of the spray wand. You’ll need to use a small screwdriver to help tease the rubber washer out of the nut and then some pressure to push the spray tip out of the nut (after you have removed the fan adjustment tip from the spray tip) as there’s a small rubber ‘o’ ring on the tip that interferes with the nut. Just look at the pictures attached to this review and you’ll see what to do – something like this would be helpful in the instructions however. Even better would be an extra plastic nut so you can avoid dismantling the variable spray head altogether. The other item that was missing was a pressure relief valve for de-pressurizing once the job was done, however the tank lid screwed off easily and there was no back splash when the lid was loosened and the pressure released. One thing I really liked about the sprayer is the size of the opening at the top of the spray tank. It measures about 5 ½” round and this makes it easy to get your hands in to reach the bottom of the tank with a sponge if there is some residue from deck stain or sealer left over after rinsing out the tank. The top of the tank also has a removable strainer although it is quite a coarse strainer so it will not stop smaller particles from getting into the tank. I also liked the fact that the spray handle has a security clip, so if the sprayer is loaded with something harmful or messy, you can lock the trigger to keep it safe from children. The spray wand can also be clipped onto the spray tank lid so it can be securely stored when not in use. We mixed up a powdered borax-based termite treatment to spray 8’ high x 40’ long interior stud wall and attached sheathing of our garage as part of a garage re-model and the backpack sprayer helped us get the job done in about 10 minutes. This job would have been a pain with our smaller pump sprayer as I would have been constantly stopping to re-prime the pump and also holding the pump tank in one hand in order to reach the tops of the wall. February 2, 2014
2 3 4 5 6 >>


Standard Shipping includes delivery by small parcel service. Processing time varies by product.

Orders for this item may be expedited for an additional fee.

Other Delivery Options:

Express and Expedited shipping options are also available. Estimated arrival times are available in checkout.

If product is eligible for shipping to AK, HI and US Territories additional transit time and remote surcharges may apply.