0042206039002

Melnor

Model 3900H

Internet #203134126

Heavy Duty Pulsating Sprinkler

$13.99 /each

Frequently Bought Together

Product Overview

The Heavy metal base of the Melnor 3,900H Heavy duty Pulsating Sprinkler provides a steady platform for watering large lawn areas up to 5,600 sq. ft. The rust proof design will provide years of service.

California residents: see   Proposition 65 information

  • Heavy duty pulsating sprinkler
  • Durable all metal sprinkler head
  • Sturdy metal base
  • Rust-proof

Info & Guides

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

Specifications

Dimensions

Details

Warranty / Certifications

More Products With These Features

Search

Customer Questions & Answers

5 Questions13 Answers

Customer Questions & Answers

Heavy Duty Pulsating Sprinkler
Heavy Duty Pulsating Sprinkler

Ask your questions. Share your answers.

 
 
Clear Search Term
 
 
Sort By:
This question is from Heavy Duty Pulsating Sprinkler
 
4 answers

Is the base metal or plastic?

This question is from Heavy Duty Pulsating Sprinkler
Asked by
mpls, mn
Read all my Q&A
April 21, 2016
0points
0out of 0found this question helpful.
Was this helpful?helpful0unhelpful0

Answers (4)

Asked by
Little Silver, NJ
Read all my Q&A
Home Improvement Profile: DIYer
May 11, 2016
Answer: 
Metal I didn't want a plastic one this one is solidly built.
0points
0out of 0found this answer helpful.
Was this helpful?helpful0unhelpful0

Asked by
Read all my Q&A
April 25, 2016
Answer: 
Metal base, the extra weight really helps to hold it down.
0points
0out of 0found this answer helpful.
Was this helpful?helpful0unhelpful0

April 22, 2016
Answer: 
The base is made of metal.
0points
0out of 0found this answer helpful.
Was this helpful?helpful0unhelpful0

Asked by
Read all my Q&A
April 22, 2016
Answer: 
Yes the base is metal it is made from Zinc.
0points
0out of 0found this answer helpful.
Was this helpful?helpful0unhelpful0
This question is from Heavy Duty Pulsating Sprinkler
 
4 answers

what would be a few things to check that would cause sprinkler to not return to its starting point?

This question is from Heavy Duty Pulsating Sprinkler
Asked by
Read all my Q&A
May 10, 2015
0points
0out of 0found this question helpful.
Was this helpful?helpful0unhelpful0

Answers (4)

Asked by
SW PA
Read all my Q&A
Home Improvement Profile: DIYer
July 27, 2016
Answer: 
In my previous post(s), I said I fixed this problem. I did but the diffuser has to hit the head too many times to reverse at either end. That bothered me a lot.
I switched to a smaller gauge red hard solderless connector piece of plastic on the diffuser hang down hammer pin. Just pull the metal part out of the connector. I eliminated the heat shrink tubing, the blue connector piece, and used the red Read More
In my previous post(s), I said I fixed this problem. I did but the diffuser has to hit the head too many times to reverse at either end. That bothered me a lot.
I switched to a smaller gauge red hard solderless connector piece of plastic on the diffuser hang down hammer pin. Just pull the metal part out of the connector. I eliminated the heat shrink tubing, the blue connector piece, and used the red one with a tight fit now. I sawed off the end of the hard red plastic flush with the pin end.
I wanted 100% reversing without much of a delay at the end of either direction of travel. I finally got 100% reliable reversing.
The small coiled spring below the bigger spiral spring up on top was the other problem. One end has an L shaped end that fits into a slot in and under the upper movable mechanism that reverses the head direction.
On the other end of this smaller spring has a small "bump" or "raised area" on the straight part of the spring and near the end. I greased this entire mechanism, BTW. It was after I removed (you don't have to do that) the smaller spring that I noticed something. If the spring was in the lower movable mechanism hole and the "bump" was below the hole it fit into, then there would be less tension on that spring and the reversing mechanism. I tried it and now I have a quick self reversing head and at slightly lower pressure than my 40 PSI, but not much lower. 20 PSI is total sales hype.
You can change the spring bump with some hemostats or tweezers without disassembly of the mechanism.
Here's the assemble order if you remove these two reversing mechanisms and the spring. First on the shaft of the long pin is a small flat washer greased with silicone. Next, the upper greased mechanism with the slot goes on. This is followed by the lower assembly with the spring end hole and then another flat washer. Then, the E clip is replaced. Don't loose it. Put the bump end into the lower assembly hole until the bump area is below the hole. Next, the L end spring goes into the slot in the upper assemble and under it- - under the flat mechanism to hold the spring under tension in place.
So, it took me some time but you might need a HARD plastic piece on the diffuser pin and to make sure the small spring bump is placed as described above. I am not sure how this spring position got changed but it happened.
I took a piece of flat grocery store pastry clear plastic and made a split washer to go in the bottom gap that the entire rotating head mechanism rests on to reduce friction. Like in another post, mine decayed and was lost. Just slide this piece on and make sure it is a thin piece of plastic. Make sure the head is almost frictionless and not binding at all. Some water will normally leak out here. It will work without this split washer but I remember seeing one on my older 1990s squared off diffuser end. I am not sure how you fix the current egg shaped diffuser end mechanism but this should help steer you in the possible right direction.
HD does not carry a replacement washer. Just make one with a drill and use some type of cutting shears on the outside edge. Get rid of any burrs.
HTH,
Stefan Read Less
0points
0out of 0found this answer helpful.
Was this helpful?helpful0unhelpful0

Asked by
SW PA
Read all my Q&A
Home Improvement Profile: DIYer
July 23, 2016
Answer: 
My NO-REVERSE PROBLEM SOLVED. This has nothing to do with the "flipping wire" hairpin that hangs down and limit switch slip rings of stainless steel. I have an older model from 20 years ago but it the same design as this one.
You can test the sprinkler by flipping the "flipping wire" up and see if the head rotates 360 degrees. If not, screw the needle valve all the way in so it is hit by the moving
Read More
My NO-REVERSE PROBLEM SOLVED. This has nothing to do with the "flipping wire" hairpin that hangs down and limit switch slip rings of stainless steel. I have an older model from 20 years ago but it the same design as this one.
You can test the sprinkler by flipping the "flipping wire" up and see if the head rotates 360 degrees. If not, screw the needle valve all the way in so it is hit by the moving diffuser solidly at the point of the needle. This should make the sprinkler head rotate 360 but it will never reverse, of course. Back off the needle screw. You have lost the plastic hammering part on the diffuser pin. You have my problem, no reversing. Look from one side and find the flat sheet metal that is L shaped with a bent over tang. Look just above the top most part of the hairpin "flipping wire". Reference Melnor 3910 sprinkler instructions for the Melnor terms below in the parenthesis. So, there is a stud or pin that points downward on the moving balance hammering weight (the "diffuser") and it hits the bent over tang on the larger and bigger flat sheet metal piece above where the limit switch and "flipping wire" assembly are located. The pin is above the very top of the ends of the "flipping wire" or hairpin. On the longer flat sheet metal with the bent over tang. the diffuser's pin hits this flat 3 mm horizontal by 8 mm vertical bent over tang to reverse reset the sprinkler using a hammering action of the moving "diffuser" on that tang. The problem is that the HARD plastic breaks off with time. You put a piece of short heat shrink tubing on the pin and shrink it down to increase the diameter slightly. That is a spacer. Cut the bottom flush with the bottom of this metal stud or pin on the diffuser. The pin on my older unit has a flat spot on one pin side, FYI. The pin is on the moving oscillating balance weight or diffuser and is molded right into it.. Take a hard blue plastic solderless connector terminal and pull the metal part out. Force the blue tubing over the heat shrink tubing on the pin. Cut the bottom blue plastic off flush with the pin. This pin and blue plastic should miss the top horizontal part of the sheet metal that is not part of the vertical bent tang area. It must pass over that top sheet metal flat area without hitting it. You can't drive nail in with a rubber hammer. It takes a solid metal hammer. This takes a hard plastic tubing piece on the pin to hit that tang and transfer the diffuser energy of motion to the head. That hammering then re-cocks or reverses the sprinkler head with that flit-flit-flit sound you used to hear. I am sorry but this is hard to describe but mine works fine now. HTH, Stefan
Read Less
+2points
2out of 2found this answer helpful.
Was this helpful?helpful2unhelpful0

Asked by
Read all my Q&A
Home Improvement Profile: Other
June 1, 2016
Answer: 
I don't believe that minimum 20 PSI statement.
First, let's look at how this thing works. The bottom hairpin clips reverse the direction using the bottom slip rings.
Secondly, the moving top counterbalance or swing arm is sprung by the top coil spring and that action is what moves the entire head step wise and then a reverse of the direction. It's a hammer, sort of.
What's the problem? Low water Read More
I don't believe that minimum 20 PSI statement.
First, let's look at how this thing works. The bottom hairpin clips reverse the direction using the bottom slip rings.
Secondly, the moving top counterbalance or swing arm is sprung by the top coil spring and that action is what moves the entire head step wise and then a reverse of the direction. It's a hammer, sort of.
What's the problem? Low water pressure but you can't increase your 45 PSI city water or regulator to 200 PSI to get this thing to reverse.
Let's test the counterbalance arm that cocks of the coil spring.
Look at the exit orifice on the center support tree. This is the direction in this article.
Rotate the top counterbalance to the left. You can't see the orifice now. Water shoots up into the U channel before the balance arm gap. It then shoots across that gap and hits the other outer U channel that is used to cock or determine the amount of spring compression of the top counterbalance spring.
Notice how the water is channeled after the gap to be deflected and to shoot outwards from the sprinkler. That's key to the force of the cocking action! Some of the water hits this "sail" surface after the gap and cocks the spring. Some or most of the water shoots outwards.
When the arm movers to the right, it is cocking the coil spring on the swing arm. When released, it moves the rotation or direction of the water spray. At the end of the travel, it has to have enough power to trip the hairpin to reverse the direction. That's the root cause of the problem; not enough force at either end of sprinkler head travel.
The test. Place a piece of electrical tape across the end of the channel after the gap and at the very end of the swinging counterbalance arm. Extend the tape 1/4" past the left edge of the swing arm channel as viewed looking at the large exit orifice to create a larger "sail" force. Tape the electrical tape to the top (outer) end of the channel on the arm and then wrap the tape along the bottom of the arm also. You have now blocked all the water from shooting outwards after the end of the arm. It has to exert more force on the moving counterbalance swing arm.
Make sure the hairpin is straight down and close to the center support structure and the arm easily reverse by hand.
Turn on the water. After a few helpings of reversing, your sprinkler should now travel back and forth.
Mine did. There are a few fixes for this. You now know the problem is a lack of force or water power to cock the swing arm spring on your unit.
You can install/ glue a wedge or ramp on the inner channel or the outer channel depending on how you need to deflect the water stream direction to create more force. Of course, you can install a block at the end of the swing arm after the gap to increase the force at lower pressure.
You can install a piece of screen across the exit end of the swing arm to stop some but not all of the water traveling outwards. Try a cylinder of screening open at one end and use copper wire to keep it in place at the end of the swing arm.
You could decrease the diameter of the exit orifice but that could be tricky for most people to do. It also risks permanent orifice damage. A smaller aperture will increase the water pressure and thus the velocity. More velocity will increase the momentum force you need but decrease the water flow. There is no free lunch here.
You should be able to figure out the problem now and figure out some type of non-damaging solution.
Newton's Law, force equals mass times acceleration. Black tape created more mass hitting the tape sail at the same flow rate of water. Yo uneed more kinetic energy and mas both.
At a constant 45 PSI and a short hose, my stinking sprinkler will not reverse or even try to reverse by the partial cocking of the spring or be able to rotate the hairpin clips. My unit is not frozen up, full of scale, or have any friction points.
This is a poor design because of the angles of the exit before the gap and the slope after the gap on the swing arm.
NO WAY it will work at 20 PSI. I cut my ball valve off partially off slowly and it had no effect except to lower the water delivery.
Oh yeah. With the tape in place, my sprinkler works perfect as far as back and forth motion and even makes the original sounds on reversing to start a new slower sweep of the water.
Gilmore makes better ball valve shut offs and other stuff but they don't make this type of sprinkler.
Create your own solution.
Stefan Read Less
+1point
1out of 1found this answer helpful.
Was this helpful?helpful1unhelpful0

Asked by
Read all my Q&A
May 11, 2015
Answer: 
The pulsating sprinkler requires a minimum of 20 PSI in order to rotate properly - if that is not the problem check the clip on the backside of the head. In order for it to return to its starting point the clip should be down.
+3points
4out of 5found this answer helpful.
Was this helpful?helpful4unhelpful1
This question is from Heavy Duty Pulsating Sprinkler
 
2 answers

what is the shipping box dimensions

This question is from Heavy Duty Pulsating Sprinkler
Asked by
Miami, FL
Read all my Q&A
March 26, 2014
i need to know what the size is from the box
0points
0out of 0found this question helpful.
Was this helpful?helpful0unhelpful0

Answers (2)

Asked by
Little Silver, NJ
Read all my Q&A
Home Improvement Profile: DIYer
May 11, 2016
Answer: 
Mine came with a couple items, this is about 10 inches by 5 by 8....just a rough guess sorry recycled the box.
0points
0out of 0found this answer helpful.
Was this helpful?helpful0unhelpful0

Asked by
Oak Grove Mo
Read all my Q&A
June 19, 2014
Answer: 
Just a small box 8" X 12" and its very well packed.
0points
0out of 0found this answer helpful.
Was this helpful?helpful0unhelpful0
This question is from Heavy Duty Pulsating Sprinkler
 
2 answers

item melnor # 3900h heavy duty pulsating sprinkler which stores in dallas area carries this product

This question is from Heavy Duty Pulsating Sprinkler
Asked by
none
dallas tx
September 19, 2013
0points
0out of 0found this question helpful.
Was this helpful?helpful0unhelpful0

Answers (2)

Asked by
Oak Grove Mo
Read all my Q&A
June 19, 2014
Answer: 
You can order online from www.homedepot.com or several other companies on line. Home Depot has the best price.
0points
0out of 0found this answer helpful.
Was this helpful?helpful0unhelpful0

Asked by
THD Customer Support
Kennesaw, Ga
September 22, 2013
Answer: 
Thank you for your recent inquiry with The Home Depot. This item is an online exclusive and is not available in your local Home Depot store. It can be ordered online and shipped directly to your home or business. For any other questions, please call us at HomeDepot.com Customer Service 800-430-3376.
0points
0out of 0found this answer helpful.
Was this helpful?helpful0unhelpful0
2 »
  • 2016-09-08 T12:12:08.799-05:00
  • bvseo_lps, prod_bvqa, vn_prr_5.6
  • cp-1, bvpage1
  • co_hasquestionsanswers
  • loc_en_US, sid_203134126, prod, sort_default
2 »
  • bvseo_sdk, java_sdk, bvseo-3.1.1
  • CLOUD, getContent, 23ms
  • QUESTIONS, PRODUCT

Customer Reviews

Rated 4.0 out of 5 by 32 reviewers.
Rated 5.0 out of 5.0 by Great lawn coverage Great value! This sprinkler covers small and large areas with plenty of water. August 9, 2016
Rated 4.0 out of 5.0 by Works Great But NO Directions Great Product !! Unfortunately NO Directions or explanation of how to use the products features. Would be nice for the price of a piece of paper to include the control points, otherwise I would have given 5 stars. July 12, 2016
Rated 2.0 out of 5.0 by Not impressed The quality of the materials in this sprinkler does not match my own expectation of "heavy duty." At best it is typical Chinese quality. I will be looking at a local supplier to get something worthwhile. June 16, 2016
Rated 5.0 out of 5.0 by Melnor Heavy Duty Sprinkler I bought two of these and am very impressed so far. Love the fact that they are all metal with no plastic parts to break. This also gives them a heaviness so they stay right where you set them, which is refreshing. They don't leak, can be set to a 360° rotation if desired, and have nice distance. Their less than "premium-brand" pricing is definitely a pro, as well. June 16, 2016
Rated 5.0 out of 5.0 by Excellent not cheap plastic Very nice product. Am pleasantly surprised that it solidly built, metal and covers a nice area of the yard. I plan on getting a second one so that I can get complete coverage. May 11, 2016
Rated 5.0 out of 5.0 by good product When you need a movable sprinkler, this one (all metal) is a really good one. May 24, 2016
Rated 5.0 out of 5.0 by Lays Down the Law I used this for the fourth time today. I wasn't able to use the oscillator today because of wind. I took this one to the front yard and not only did it cut through the wind but it also delivered a really good soaking. I still can't get over the build quality either. This sprinkler really laws down the law. December 21, 2015
Rated 5.0 out of 5.0 by Great sprinkler I like the fact that this sprinkler is very adjustable, pattern, spray and distance. Great for irregular shapes that you want to water. September 22, 2015
  • 2016-09-08 T12:41:06.597-05:00
  • bvseo_lps, prod_bvrr, vn_prr_5.6
  • cp-1, bvpage1
  • co_hasreviews, tv_32, tr_32
  • loc_en_US, sid_203134126, prod, sort_default
2 >>
  • bvseo_sdk, java_sdk, bvseo-3.1.1
  • CLOUD, getContent, 14ms
  • REVIEWS, PRODUCT