When a house sewer blocks, the overflow relief gully outside is often the first thing to tell you — it overflows in the yard instead of inside the house, which is exactly its job. Clearing the blockage usually starts with a set of drain rods and a plunger before anyone reaches for a jetter. The Plumboss gully plunger kits are built for that first attempt.
What's in the kit
| 4-inch kit | 6-inch kit | |
|---|---|---|
| SKU | BGP4 | BGP6 |
| Price | $104.95 | $109.95 |
| Rods | 2 x BP343 poly lockfast rods, 3 ft x 3/4" | 2 x BP343 poly lockfast rods, 3 ft x 3/4" |
| Plunger | BPPL4, 4" (100mm) | BPPL6, 6" (150mm) |
The rods are sectional polypropylene with brass locking nuts that keep the sections joined while you work them into a blockage — so they don't unscrew and get left in the drain, which is the classic failure with old-style threaded rods.
4-inch or 6-inch?
Match the plunger to the drain you're clearing:
- 4-inch (100mm) plunger — the standard house sewer size. If you're only buying one kit, this is the one.
- 6-inch (150mm) plunger — for 150mm sewers on larger residential, multi-dwelling and commercial jobs.
The rods suit 4" and 6" sewer drains and, in some cases, 3" and 3½" stormwater drains and downpipes. The plunger needs to be close to the pipe size to build pressure — a 4" plunger in a 6" pipe just pushes water around it.
How to use a gully plunger
- Find the access point. The overflow relief gully or a sewer inspection opening downstream of the fixtures, ideally the one closest to the blockage.
- Protect yourself. Sewage is a biohazard — gloves, eye protection and closed footwear as a minimum.
- Assemble and lock the rods with the plunger on the leading end. Make sure every brass locking nut is fully engaged.
- Feed the rods in and work the plunger with firm push-pull strokes. The plunger drives a pressure wave along the pipe that can shift soft blockages like paper and waste.
- Watch the water level. When the level in the gully drops and flows away, run water to flush the line.
- Clean and disinfect the rods before they go back in the van.
When a plunger isn't enough
Plunging shifts soft blockages. It won't fix tree roots, broken or collapsed pipe, displaced joints or hard build-up. If the blockage keeps coming back, or the rods won't pass a point, the line needs inspecting — a drain camera shows what's actually down there before you quote a repair. Blockages on the authority's side of the property connection are the water authority's responsibility; check where the boundary is before doing more than clearing.
After a repair, test the line with test plugs. Browse more in drain cleaning tools and chemicals.
Frequently Asked Questions
What size gully plunger do I need for a house?
Most house sewers are 100mm, so the 4-inch (100mm) kit is the usual choice. Use the 6-inch kit on 150mm sewers.
What comes in a Plumboss gully plunger kit?
Two 3 ft x 3/4" poly lockfast sewer rods and a plunger — 4" (BPPL4) in the BGP4 kit or 6" (BPPL6) in the BGP6 kit.
Why do the rods have brass locking nuts?
The locking nuts keep the rod sections joined while you work them into a blockage, so a section doesn't come loose and get left in the drain.
Can a gully plunger clear tree roots?
No. Plunging clears soft blockages. Tree roots, broken pipes and hard build-up need cutting, jetting or repair, usually after a camera inspection.