Independent comparisons. We may earn from shop links. More info

How to set a circular sprinkler

Updated: 22 October 2026

The head is already on the hose, the tap is open, and the jet is hitting the path or sitting still. Setting a circular sprinkler is two jobs that people mix up: where the arc stops, and how far the jet throws. An impact sled and a GRÜNTEK-style spike use collars or rings. A three-arm rotary in this set does not. Peter F. updated this page on 22 October 2026 from the listings in the [circular sprinkler comparison](/hub/garden-watering/circular-sprinkler) plus public UK setup notes. A qualifying purchase can earn us a commission at no extra cost to you. If you have not bought the head yet, the type belongs on the [circular sprinkler buying guide](/hub/garden-watering/circular-sprinkler/sub/circular-sprinkler-buying-guide).

The head is already on the hose, the tap is open, and the jet is hitting the path or sitting still. Setting a circular sprinkler is two jobs that people mix up: where the arc stops, and how far the jet throws.

Our top picks

Ram Ram rotary

Best overall

Ram Ram rotary
9.0/10about £6.99
View offer
GRÜNTEK GRÜNTEK 296.000

Rank 2

GRÜNTEK GRÜNTEK 296.000
8.9/10about £22.78
View offer
STYDDI STYDDI HG75-DEF

Alternative

STYDDI STYDDI HG75-DEF
7.6/10about £26.99
View offer
On this page
  1. 1.Set the arc
  2. 2.Set the throw
  3. 3.How long, and on which lawn
  4. 4.If it stops or leaks

Set the arc

Impact heads in this set are the STYDDI zinc sled and the FANHAO metal sled. Both listings state 20° to 360°. Lawn Tiger’s setup sheet for its own impact layout is the clearest UK picture of the controls, and it is that brand’s sheet, not a specification for STYDDI or FANHAO. On that layout the trip pin, sometimes called a V-clip, stays down when you want a sector and goes up for a full circle. Two collars set the angle the arm is allowed to travel. Easy Garden Irrigation describes the same idea: trip pin up for 360°, collars for the angle. If the jet still crosses the path, move a collar rather than hoping the next circuit will be shorter. The GRÜNTEK spike, B07F1YWC7C, lists a sector from 30° to 360° and four modes named FLAT, FAN, LARGE, and MINI. Rings set the arc. Three-arm rotaries do not have that stop. Ram, Green Haven, Wisdomwell, Dermasy, and Fipfovpa describe 360° rotation. Do not hunt for a collar that is not in the box. Place the head so the whole circle lands on grass, or move it between two spots. A path along one side of a rectangle is a reason to consider an oscillating bar instead, which is circular vs oscillating sprinkler.

Set the throw

On an impact head the small screw on the side is the diffuser. Easy Garden Irrigation says turning it clockwise shortens the jet and widens it into a finer spray. Back it out and the stream reaches further and hits harder. STYDDI reviews describe that side screw as the control that switches a jet for a fine spray. Nozzle angle is the rotary version of the same idea. Ram and Green Haven list nozzles from about 15° to 45°. A steeper angle throws higher and often shorter. A flatter angle reaches further and is easier for wind to push. Dermasy’s listing says not to overtighten the nozzle body.
Ram Ram rotary

Testsieger

Ram Ram rotary
9.0/10about £6.99
View offer

How long, and on which lawn

The Royal Horticultural Society says an established lawn can be left to brown and will recover. The RHS watering guidance prefers morning, when less water sits on the leaf into the night. A new lawn is the exception they describe. Put a straight-sided jam jar on the grass in the pattern and stop when it holds about 13 mm. That August lawn note is a depth, not a timer. Check the jar instead of copying a neighbour’s runtime. The jar does not override a ban notice.

If it stops or leaks

A head that stops at one side is often doing what the collar told it to do. Look at the trip pin before you call it faulty. Lawn Tiger’s sheet says a stall against the collar on that layout is usually low pressure, and it talks about needing about 2 bar or more for a part-circle setting. Dermasy prints its own minimum of about 28.4 psi, which is about 2 bar. Below that, the arms stop. Dirt is the next cause. Hozelock’s Round Sprinkler Pro FAQ, which is not the 2515 dial in this set, says clean the inlet gauze, soak scale in warm water and vinegar. Reviewers also suspect grit when a GRÜNTEK mechanism sticks and leaves a fixed jet. A leak at the nut is a washer or a thread, not a blocked nozzle. Seat the washer, and do not keep tightening until the plastic creaks. If water comes out of the wall behind the tap, stop and call a plumber. If a spike might meet a buried cable or pipe, stop before you push.

Common questions

How do I set a full circle on an impact head?
On the Lawn Tiger layout the trip pin goes up and the collars are left clear so the arm can travel the whole way. STYDDI and FANHAO list 20° to 360°, so a full circle is within the printed range. Confirm it with one slow pass. A pin left down will stop the head at the collar and look like a fault.
Why will the three arms not spin?
Pressure, a clogged nozzle, or an overtight joint. Dermasy’s page says about 28.4 psi and tells you not to overtighten the nozzle body. Clean the jets, run one head, and ease the joint. Green Haven reviews repeat the same stop. There is still no sector collar to adjust.
How long should it run?
On a new lawn, stop at about 13 mm in a jam jar, preferably in the morning. There is no single minute count, because the tap decides the rate. On an established lawn the RHS advice is to leave it. A ban notice, where one is in force, overrides both.
What if the leak is at the nut?
Reseat the washer and check you have not forced a US thread into a UK click fitting. Tightening further cracks the body, which is the Dermasy warning. A leak from the brickwork at the outside tap is a plumber’s job, not a sprinkler setting.
Can I link two heads to finish faster?
The GRÜNTEK and Dermasy listings mention a series connection. The flow splits. The far head is the one that stalls on a modest supply. Finish one circle, then move the head, unless you already know the tap holds pressure with both running.

Related pages

Sprinkler hosepipe ban

Circular sprinkler

Best circular sprinkler for a sector or small lawn

Circular sprinkler buying guide for shape and the tap

Circular vs oscillating sprinkler: circle or rectangle

Sources

Public UK sources for temporary use bans and watering, plus a buyer’s note on impact heads and hose length. Prices, stars and review counts are the amazon.co.uk lines saved with this comparison. Ban status is as of 20 October 2026 and is by supplier, not national.

  1. Flood and Water Management Act 2010, section 36 (retrieved 22.10.2026)
  2. Water Use (Temporary Bans) Order 2010 (retrieved 22.10.2026)
  3. Thames Water — temporary hosepipe ban (retrieved 22.10.2026)
  4. Anglian Water — temporary use ban notice (retrieved 22.10.2026)
  5. South East Water — Sussex hosepipe FAQs (retrieved 22.10.2026)
  6. RHS — watering (retrieved 22.10.2026)
  7. Easy Garden Irrigation — impact sprinkler guide (retrieved 22.10.2026)
  8. Masseys DIY — Hozelock garden sprinklers (retrieved 22.10.2026)