Hot Water Services

Darius from Plumbdog is out on-site at a large accommodation complex in Perth to troubleshoot major commercial hot water issues — and this setup is no small job! With three huge Thurman 32 water heaters running on a circulating ring main, this system provides hot water for dozens of guests… when it’s working properly.

The Problem

The property reported inconsistent hot water and low flow, and it didn’t take long for Darius to find the culprits:
•A failed Grundfos circulating pump stopping the ring main flow
•An electrical fault preventing both pumps from running correctly
•Corrosion and missing pressure relief protection on the system

The Fix

To get everything running safely and efficiently again, Darius:
•Installed new Grundfos dual pumps for reliability and redundancy
•Added an expansion control valve to prevent over-pressurisation
•Cleaned and checked all pipework and connections for corrosion
•Tested system operation — restoring 96L/min of steady hot water throughout the building

 “Commercial hot water systems need balance — if one component fails, the whole setup suffers. Regular servicing is the key to keeping everything flowing.”

The Result

Hot water fully restored across the complex

Circulation loop now running smoothly with proper pump control

Pressure safely managed with new relief and expansion valves

System protected for the long haul with proper maintenance practices

Location: Perth, WA
Need expert help with your commercial hot water system?

Fault-Finding a Continuous Flow Unit That’s Not Firing in Ardross

In this job, Rich is called out to an Ardross property with a frustrating problem:
Hot water is working on one side of the house, but completely dead on the other.

The homeowner has:

• A gas continuous flow unit (not firing) on one side
• A gas storage unit (low pressure, but still heating) on the other

Let’s run through the full on-site diagnostic process — and show why checking the basics first always pays off.

🔍 Step 1: Test the Closest Tap

Rich starts by turning on the nearest hot water tap to the continuous flow unit — the laundry tap.

• The unit doesn’t fire
• That confirms there’s no activation happening when hot water is called

🔌 Step 2: Confirm Power Supply

• Rich checks the powerpoint and power cable with a tester
• ✅ Power is live at the socket and flowing through the lead
• Next, he removes the front cover of the unit to check for any signs of startup
• Still nothing — no electrical activation, even though power is confirmed

🔧 Step 3: Suspected Internal Fault

With the system receiving power but failing to respond, the likely issues could be:

• A faulty flow sensor
• A failed PCB (printed circuit board)
• Or another internal component not allowing startup

💬 “At this point, we’ve ruled out external factors. No point throwing a new unit on the wall without knowing what’s wrong with the current one.”

💡 Final Recommendation: Replace — But With Purpose

Due to the unit’s age and the lack of electrical response, Rich recommends a replacement system.

But not just a like-for-like swap — because:

• It’s better to troubleshoot first, so you don’t repeat the problem
• You get the chance to size the new unit correctly
• And ensure you’re not replacing a working system due to a simple oversight

🐾 Plumbdog — Perth’s real plumbers with all the gear, every idea, and a methodical approach to hot water troubleshooting. 

📞 No callout fee | ✅ Gas & electric hot water specialists | 🔎 Fault diagnosis done right