How to Protect a Hydronic Heating System From the Damaging Impact of Poor Water Quality

A look at how magnetic filtration helped lower heating bills and extend equipment life in one north-eastern home

As winter descended upon Westborough, Massachusetts, last December, Joe Geraghty, Business Development Manager at Sweeney Rogers Geraghty Inc. (SRGI), noticed a near-constant background noise in the four-bedroom home he shares with his wife — and it wasn’t the relaxing kind of white noise that some find enjoyable. It was the home’s ten-year-old, cast iron, oil-fired boiler.

And it wasn’t just running off and on…it was running all the time.

“It’s a new house for us, so it was hard to tell what was going on at first,” says Geraghty. “It’s not like we had to adjust the thermostat – the house was keeping its temperature, but the boiler was working hard to keep it steady.”

Geraghty tried adding insulation to the house, thinking that might alleviate the problem, but to no avail. The boiler just kept turning on. “With it running all the time, we were using a lot of oil. When the weather really got cold, our oil bill spiked up to almost double what it had been in the fall.”

Geraghty soon found that instead of filling his home’s oil tank with number 2 fuel oil every four to five weeks as he had expected, it required filling every two to three weeks. As fuel expenses mounted, Geraghty began to suspect what might be the origin of the problem.

He decided to ask Steve Milligan, a former heating contractor and now Hydronic Specialist Trainer at SRGI, to carry out a thorough check of his system in order to figure out what was going on. As a full service manufacturers rep organization specializing in plumbing and HVAC products, SRGI trainers and techs are well versed in problems such as this one.

Unravelling the Mystery

Upon inspection, Milligan confirmed Geraghty’s suspicions: There was a blockage in the ECM pump. The cause of the blockage was iron oxide sludge, also known as magnetite.

“I’ve seen this problem plenty of times,” explains Milligan. “Many homeowners just assume it’s an issue with the boiler, heat exchanger or the circulator, and often end up buying costly replacement parts which just fail again and again.”

But Geraghty and Milligan knew better, because this wasn’t the first time the ECM pump had failed.

The system in Geraghty’s house has two pumps, one ECM and one traditional. “I knew that the previous owners had replaced the ECM pump about two and a half years ago,” says Geraghty, and it was already clogged again. “Looking back, I would attribute that first failure to magnetite in the system. It’s just not good water for a boiler system.”

An Easy Solution

Luckily, working for SRGI, Geraghty and Milligan had the answer to the problem sitting right on their shelves: a MagnaClean Professional2XP™ Magnetic Dirt Filter, manufactured by ADEY Innovation LLC.

Milligan hadn’t found a tremendous quantity of magnetite inside the clogged ECM pump. But it doesn’t take much to foul one of these high-performance pumps, which contain magnets as part of their variable speed motors. These magnets pull damaging iron oxide from the system’s water right into the circulator. So Milligan knew he had to get all the magnetite out of the system.

“After training contractors about this product, and comparing it to other brands, I knew the MagnaClean Professional2XP was the right filter for the job,” says Milligan. With 1¼-inch NPT fittings to match the home’s pipe size, the Professional2XP seemed to be the perfect answer.

Following the Best Practice protocol that Milligan learned from ADEY — and has trained countless other installers to use — he cleaned the system with ADEY’s MC3+™ cleaner, flushed the system, and installed the filter.

After the Professional2XP was installed, Milligan ran the boiler for 15 minutes to ensure that the filter collected any magnetite and scale remaining, before testing and allowing the system to be switched back on.

“What we found in just the 15 minutes run-time was incredible,” says Milligan. “It’s clear to me that these filters are definitely a necessity for any hydronic heating system, whether it be old or new.”

After installing the filter, Milligan added ADEY’s MC1+™ protector in order to limit the formation of iron oxide, and completed a test of the system’s water quality using ADEY’s engineers test kit. “I found the kit really useful. It’s unusual to find a kit that allows you to test for pH, copper, chloride, iron and water hardness all at the same time,” notes Milligan.

Geraghty underscores the importance of using all the steps in the process, instead of just installing the filter. “The cleaner going through the system is what’s going to break up the magnetite in the cast iron radiators. It’ll stir the system up so that the magnetite can actually be collected when it gets to the filter. Then the inhibitor [protector] helps keep magnetite from coming back. I would definitely recommend doing it that way — using all the steps — to get the best results.”

The Results

Immediately after Milligan completed the installation, things began to improve around Geraghty’s house. “My wife was the biggest proponent of this installation, to make sure the boiler wasn’t running so much,” says Geraghty. “Believe me, the Professional2XP has made a big difference.”

The difference has indeed been substantial. Geraghty estimates he’s saved between 5-10% on his oil bill since installing the filter. In addition, “I’ve probably doubled the life span of the pumps. It’s a huge savings compared to the cost of the filter,” he says.

Because Geraghty’s situation didn’t unfold quite as one might expect, with cold spots in the baseboards, and cold rooms in the house, guessing the source of the problem required some detective work and insider knowledge. But the problem they found — iron oxide sludge — isn’t unique.

Manufacturers Taking Notice of Magnetite

In fact, the problems caused by iron oxide and other water quality issues are becoming more prevalent as high-efficiency (HE) equipment becomes increasingly popular.  

“Take HE wall hung boilers, for example,” says Geraghty. “They have lower tolerances for improper pH and bad water, because they have stainless steel or aluminium heat exchangers. They’re also much smaller than the old cast iron boilers, so they’re more prone to fail under poor water conditions than an old cast iron boiler is. Manufacturers are really starting to feel it in their wallets.”

As a result, boiler producers have begun to require water testing when problems come up. What’s more, they are denying warranties if the water quality is not up to par.

And it’s not just boilers that are negatively affected by poor water quality. As in Geraghty’s situation, magnetite can have a devastating impact on ECM pumps. According to Dr. Neil Watson, ADEY Chief Technical Officer, “Nearly 70 percent of circulator pumps returned to manufacturers fail due to iron oxide damage and other water quality issues.”

These increasingly prevalent issues caused by poor water quality make magnetic dirt filters like the MagnaClean Professional2XP absolutely essential to any new or retrofit installation. Taking the time to install this relatively inexpensive device ensures warranty issues don’t come up later, and potentially extends the life of expensive equipment.

As for Geraghty’s house, Milligan says, “I’ll be going back after the summer months to check the filter again.” At that point, the systems should be cleaned, flushed and protected in order to be made ready for the cooler months ahead.

“Many of us have been in these situations before and often paid for emergency service call-outs, when in fact we could’ve just prevented the cost by being prepared and on top of our annual system service,” Geraghty says. “It gives me peace of mind knowing that my system is now fully protected.”