Blocked Bathroom Drains Murrumbeena VIC 3163 – Internal Drain Blockage at Frogmouth Connection

Overview of the Problem – Internal Bathroom Drains Blocked

At a property on Dandenong Road in Murrumbeena VIC 3163, opposite Chadstone Shopping Centre, our team at Your Choice Plumbers was called out after the owners reported blocked bathroom drains affecting the wash basin, bath, and shower in the same bathroom.

The owners explained that the drains had been going slow for a while, but by the time we arrived they had stopped draining altogether. The shower had become unusable because wastewater was backing up into the shower base.

This is exactly the type of situation where homeowners start asking, “why are all the bathroom drains blocked at once?” or “why is the shower backing up when the basin and bath are slow too?” As an experienced plumber Murrumbeena, we often find that when multiple internal drains in one bathroom block together, the issue is usually hidden in the shared bathroom waste connection rather than at just one fixture.

Initial Checks and Why the Problem Was Unusual

Our first step was to determine whether this was a broader sewer issue or a localised bathroom drainage problem.

We checked:

• the other bathroom on the opposite side of the house
• the adjacent toilet
• the general sewer discharge performance

Those fixtures were all draining normally.

That was a very important clue because it told us the blockage was isolated to this one bathroom group, not the main sewer line serving the whole house.

We then moved outside to see how the bathroom fixtures connected to the drainage system.

Inspecting the External Bathroom Waste Connections

Outside, we found that all three bathroom fixtures were connected into a frogmouth fitting before discharging to the drain line.

The three waste connections were:

• 40mm galvanised waste pipe for the basin
• 50mm older-style bath waste connection
• 50mm shower waste pipe

All three were old galvanised bathroom drain lines and each had its own inspection opening cap located on the elbow.

That already made this case more unusual.

Even more interesting, the disconnector gully trap itself was not blocked.

When we opened the inspection caps on each of the three bathroom waste drains, they were all found to be full of wastewater. That is not normal when the disconnector trap appears clear, and it told us the real blockage was likely hiding in the shared connection point between those fixture lines and the ORG / riser connection.

Why This Internal Drain Blockage Needed a Different Approach

We explained to the owners that in order to diagnose and clear the problem properly, we needed to use high-pressure jetting on all three bathroom waste lines.

Because we were jetting back toward the internal fixtures from the inspection openings, we advised them to cover the basin, bath, and shower outlets inside the home to prevent internal splashing caused by the jetting pressure.

The plan was to:

• clear each fixture branch individually
• clear the connecting sections running down into the frogmouth
• determine what was preventing the shared waste from discharging properly toward the ORG riser

Jetting the Bathroom Waste Pipes

Due to the small access openings on the galvanised bathroom drain lines, we started with a 1/8″ whip hose fitted with a penetrating nozzle.

This nozzle had:

• 4 rear jets
• 1 forward jet

That setup gave us strong forward thrust while also cleaning the internal walls of the old galvanised pipes, which were likely carrying years of:

• rust build-up
• soap residue
• hair caught on rough corroded surfaces

We ran the whip hose through all three waste lines in both directions. Black and brown wastewater came out through the inspection openings until the water gradually started running clearer.

At that stage, each fixture branch had clearly been cleaned significantly.

Finding the Real Internal Drain Blockage

Even after cleaning the three individual fixture lines, we noticed something unusual:

Hardly any water was moving properly from the frogmouth connection toward the ORG riser.

That told us the shared connection itself was still restricted.

Because frogmouth fittings are usually surrounded by mortar to stop debris falling into the system during construction, we could not visually inspect the inside of the fitting directly. So the only option was to continue working the blockage hydraulically.

We then proceeded to jet each branch line again, this time directing the hose toward the frogmouth to break through whatever was choking the outlet.

Eventually, we started pulling out bowls of hair bit by bit.

That confirmed the actual blockage was not in the individual fixture drains themselves, but in the frogmouth outlet section where years of hair build-up had accumulated and never been properly cleared.

Reverse Jetting Through the ORG Riser

To finish the job properly, we opened the ORG grate and inserted the whip hose down the riser and into the branch connection serving the frogmouth.

This allowed us to perform reverse jetting, washing loosened debris out from the frogmouth and back into the ORG pathway.

Even then, the blockage was extremely stubborn.

So we escalated the equipment:

• switched from the 1/8″ whip hose
• to a 1/2″ hose
• fitted with a larger penetrator nozzle

That extra power finally cleared the heavy hair mass blocking the frogmouth outlet to the ORG riser.

This was a very good example of how real drain cleaning experience makes the difference. The unusual layout and misleading early signs could easily have led to only partial clearing if the job was not followed through properly.

Outcome and Client Result

• all three bathroom drains restored to proper flow
• shared internal drain blockage identified at frogmouth outlet
• years of hair build-up removed
• ORG connection cleared properly
• shower, basin, and bath all draining normally again

The owners were relieved to have the bathroom fully usable again, especially after the shower had become unusable due to wastewater backing up into the base.

Compliance & Prevention Insight

This case highlights why internal bathroom drains blocked at the same time should not always be assumed to be a main sewer blockage.

Sometimes the real issue is hidden in an older shared bathroom waste connection, especially in homes with:

• old galvanised internal drain lines
• unusual frogmouth layouts
• long-term hair and soap build-up

It also shows why partial clearing is not enough in unusual drain layouts. Without fully investigating the shared outlet path, the problem could easily have come back quickly.

Compliance with Australian Standards

All work carried out by Your Choice Plumbers is completed in accordance with the relevant requirements of AS/NZS 3500.2:2021, helping ensure drainage systems are diagnosed and cleared correctly.

In simple terms, this means your internal drainage is properly investigated so the real cause is cleared — not just the symptom.

Our Home Plumbing Experts Approach

As part of our Home Plumbing Experts approach, we focus on both repair and prevention.

We offer a Complimentary Property Protection Audit as part of our service, assessing key areas like water pressure, hot water temperature, and flexible hoses — helping homeowners stay ahead of potential plumbing failures and avoid unexpected water damage.

👉 Find out more about our blocked drains Melbourne services.