2 Practical Fixes for Hot Water Waste in Industrial Plants

If you’ve spent any time walking a production floor, you’ve probably had this conversation before. Someone mentions high natural gas bills. Someone else blames the boiler. And eventually someone says, “But the hot water barely keeps up during washdown.” I’ve seen this play out in plant after plant. And almost every time, the issue isn’t the boiler – it’s how hot water is being produced and managed.

The good news? Fixing it doesn’t require ripping out your entire system. The biggest gains often come not from replacing equipment, but from correcting how hot water is generated, controlled, and used on the plant floor. Here are two simple ways plants are boosting hot water efficiency today, based on real, everyday plant situations we see frequently.

I’ve walked into plenty of boiler rooms that looked great on paper: solid combustion efficiency, good maintenance records, no obvious red flags. Then when we step out to the sanitation area, things are a little different. Steam was being used to heat water for washdown, which meant the plant was turning water into steam, piping it across the facility, and then condensing it back into hot water. By the time that water reached the hose, a significant amount of energy had already been lost. This setup is incredibly common – and incredibly inefficient.

Why Steam Falls Short for Hot Water

Steam systems lose energy through flash steam, blowdown, radiation losses, condensate handling, and large swings in demand. Even a good boiler can only do so much when the system design works against it. In real-world conditions, steam-to-hot-water systems often operate at much lower thermal performance than expected. I think about the multiple steps needed to create hot water using steam, and the cumulative effect of inherent inefficiency at each step.
Here’s what that looks like in practice:

The 5 steps to create hot water using steam (and 5 chances to lose energy)

1. Burn fuel in the boiler to make steam
2. Move that steam through the distribution system to the point of use
3. Transfer heat from the steam to water through a heat exchanger
4. Collect and return condensate back to the boiler
5. Finally, deliver hot water for the process

Before we ran our boiler studies, our rule-of-thumb estimates were 60–70% efficiency for well-maintained steam systems, 50–60% for many plants, and under 50% for older or poorly maintained systems.

High-performing plants simplify hot water generation by producing hot water directly, firing only when needed, delivering precise sanitation temperatures, and eliminating steam traps, PRVs, and condensate return. In well-designed systems, that simplicity can push system performance as high as 99.7%.
One plant manager put it this way: “We didn’t realize how much energy we were losing until we stopped converting steam back into water.” Once steam was removed from hot water generation, fuel usage dropped—and so did maintenance calls.

Efficiency takeaway: If the end goal is hot water, generating it directly is one of the fastest ways to reduce energy loss and system strain.

Even when hot water is produced effectively, it doesn’t always get used that way. In a lot of plants, one hose is scalding, another is lukewarm, and opening a nearby valve sends temperatures all over the place. Operators respond the only way they can – by turning temperatures up “just in case.” That’s not a training problem. That’s a control problem.

Why Poor Temperature Control Wastes Energy

When hot water runs too hot or too cold, people compensate—by turning temperatures up, washing longer, or re‑doing work. The heater burns extra fuel chasing unstable demand, and none of that extra energy improves results. Instead of delivering the right heat once, the system wastes energy trying to stay usable shift after shift.

Every degree of unnecessary overheating wastes fuel, puts added stress on heaters, creates safety risks, and leads to inconsistent sanitation. On the flip side, undershooting temperature causes crews to run washdown longer, re-clean areas, and lose confidence in the system. Both scenarios reduce overall efficiency.

Plants focused on efficiency prioritize accuracy at the point of use by using precise mixing to maintain steady temperatures, distribution systems that support multiple users, and storage where needed to prevent short cycling and temperature swings. In one facility, once temperatures stopped drifting, operators stopped adjusting valves altogether.

As one maintenance lead said: “People stopped fighting the system—and our gas numbers reflected it.”

Efficiency takeaway: Stable, accurate temperatures reduce fuel waste, shorten sanitation time, and improve safety—without anyone needing to babysit the system.

The best operational improvements don’t just lower energy bills—they make the plant easier to run. When hot water is available when it’s needed, holds the right temperature, and doesn’t compete with process steam, everything downstream works more smoothly.
If you’re looking for two improvements you can make today, start here:

1. Generate hot water as directly and simply as possible
2. Deliver it accurately, consistently, and repeatably

Those changes may sound simple, but they make a noticeable difference every single day. If you’re exploring ways to improve efficiency, understanding your hot water system is a practical place to begin. Connect with a Merlo Energy expert to find out what improvements will have the greatest impact.