Hydronic maintenance: How to start up right
For a closer look at hydronic system maintenance, The News talked to two experienced contractors, one residential and one commercial-industrial. They shared their views on maintaining boiler systems.
Regarding his preventive maintenance procedures for boilers, Joe Logan, owner of Logan Service Inc., Dayton, Ohio, a residential contractor, said, “Basically I like to flush them out and put clean water in them, and clean the burners and the pilot.”
He runs the system and listens for symptoms, and watches the pressure to make sure everything is OK. “I used to change my pressure release pretty often, too.”
Bob Watson, service manager of the Brewer-Garrett Co., Middleburg Heights, Ohio, a commercial-industrial contractor, stated that if a hydronic system is heating heavy, such as an elder care facility that tends to turn the boilers on a month to 45 days early, his company will do a system seasonal start-up and then two mid-season checks.
“But otherwise, it’s basically per customer request and recommendations, and what we feel is appropriate,” said Watson. Normally, a seasonal start-up and a single mid-season check are performed.
Inspect That GadgetTo do a seasonal start-up, he related, Brewer-Garrett will first do a visual inspection, looking at the casing of the boiler for visual signs of problems. These would include improper combustion, condensation problems, overheating the boiler, and any visible signs of leakage.
Then the firm does a visual check of the burner sections and burner gas train looking for apparent problems.
“We’re looking for corroded burners, possibly deformed burners where they’ve been overheated . . . any sign of sooting, and again improper combustion showing up on the burner side,” Watson explained.
Technicians also want to make sure there’s no hydraulic fluid leakage from the motorized valves, and that the block and bleed lines are intact. They will then do a cleaning of the boiler sections and the burner.
“If there’s any system safeties that are waterside, we also tear down the low water cutoffs,” Watson noted. The cutoffs may then be repaired or replaced. Then they reassemble the equipment and lubricate.
All the procedures of their seasonal start-up normally take about two days. “We get into it because we don’t want to have to do this in the middle of December.”
Watson pointed out that his firm will also check to see that the boiler meets current regulations based on the application. “Probably the most stringent are school applications,” he said, “where you have to upgrade controls. You sometimes can’t replace things that you would normally just replace.”
Water TreatmentLooking at water treatment for his residential boilers, Logan stated, “I’ve never believed in that. I really don’t like to put anything in there. And I’ve tried several over the years.”
He added that using water by itself has never posed any corrosion or other problems for him. As noted above, he puts clean water into the system every year.
Watson does use water treatment in his commercial-industrial installations. But for a closed-loop, hot water system, said Watson, “If you have a treatment done on the initial fill, the only time you require any more treatment is if you have to completely drain the system, or if you have a substantial water loss.”
For steam systems, he continued, you basically need a monthly treatment because you do have water losses and constant water makeup.
He is currently looking at a hot water system installed in 1979 that never had any water treatment and is filled with a lot of particulate. His firm is putting filters on the system “because at this point, treatment wouldn’t get you anywhere.”
Once the system is clean, corrosion inhibitors will be added to prevent further metal disintegration.
A Boiler’s LifeThe service life of a boiler can be quite long. With the regular maintenance that he gives his residential units, Logan proclaimed, “Most of my boilers last 25 to 35 years.”
And if a boiler is sized properly and you change the water once a year, he declared, a boiler can go on for many more years. “I’ve serviced boilers that are 100 years old.”
With proper maintenance, Watson said he sees steam systems last about 18 to 20 years. Hot water systems last 25 to 30 years.
Logan remarked that he did have one customer this year who is on his third boiler in 10 years. “But that’s because it was oversized,” he said. “This particular job was oversized by 100%.”
If you don’t maintain a boiler, you can shorten its useful life substantially, Logan pointed out. A few years ago, a female customer got divorced and, because she didn’t know anything about her boiler, she had no maintenance done and let it go dry. “It was a nightmare,” he said. A service life that could go to 35 years was cut to single digits.”
If people don’t do maintenance, Watson related, “We’ve seen failures on steam boilers after three years of installation.”
He told of an inner-city church that couldn’t afford to fund annual maintenance. After only four years, its boiler failed — all the sections cracked — resulting in $15,000 in work that had to be done over the Christmas holidays.
The most common hydronic system problem that Logan sees in residential hot water systems is pump failure, “by far.” Probably 25% of his service calls have to do with the pumps.
One of the biggest complaints with steam systems, he said, is noise — “the creaking sound of pipes expanding and sometimes the banging sound of steam hitting the radiators.”
Watson noted that the most typical problem his company sees in commercial-industrial applications is in the piping system. This is the trapping of air in the lines which prevents heat from getting out to the space like it should.
Building renovations and the “quick changes” made can often generate heating system problems.
Strange But TrueThe most unusual problem Logan ever faced goes back to the divorced woman mentioned earlier. When she let her steam boiler go dry, it cracked the radiators, causing $70,000 worth of water damage to her home.
The next year, the same thing happened. But her insurance company wouldn’t pay the second time around.
Watson offered the story of a hot water system in a high-rise building where they found a 6-in.-wide by 12-in.-long piece of “stalactite” concrete inside a pipe.
This system had been in operation about 25 years. The initial diagnosis of the problem was a noisy hot water circulating pump. The crew was going to tear down and rebuild the pump onsite. When they got the pipe open, the concrete mass was sticking into the impeller pump.
The concrete “had been in the system for 25 years, there’s no doubt, because it was water-eroded,” said Watson. Most likely, during construction some concrete was accidentally dropped down a pipe when one of the upper floors was being poured. Over the years it gradually worked its way down until it reached the pump.
Efficiency BoostTo improve efficiency in a residential system, you can add automatic flue dampers and an automatic ignition system if you haven’t already done so, Logan said. But he noted that some of the new boilers go up to 90%-plus efficiency.
“But I think the trick is to have the right size boiler,” he commented.
For more efficient commercial-industrial applications, Watson said that you can look at different thermostats or control systems to shut down the boiler when it’s not needed.
A lot of people go to hot water reset controls, he stated, but “I think they cause a lot of problems with the boilers. People get too aggressive when they turn down boiler temperatures.” Turning down the temperature, he explained, can create condensation inside the boiler and rust the shell from the inside.