WEST NEWTON, Mass. — Poking around in dark, dank basements is the business of every plumbing-heating contractor. And when you’ve been exploring Boston-area basements for three generations like the folks at R.P. Holmes Corp., who knows what you’ll turn up?

“During nearly 70 years of business, you hear some weird tales and experience some strange encounters,” says Susanne Holmes, who manages the family-run heating business and is herself a licensed master plumber.

“It may also be due to my grandfather Reginald, better known as ‘R.P.’, starting the business in his home on April 1, 1931 — April Fools’ Day.” Currently the company employs 25 people and puts 15 vans on the road. They travel into Boston and the local area of Newton, a Boston suburb of 83,000. The town is comprised of 13 distinct villages, with a diverse population that includes blue and new blood.

“Many of our customers go back to R.P.’s time,” notes Susanne. “People call us because our firm worked for their grandparents, parents, uncles, and aunts.

“Today our business is two-thirds residential and one-third commercial boiler installations, with over 6,000 active service customers.”

The unusual is quite common

Not surprisingly, Massachusetts families with long histories live in homes that go far back in time.

“This area is old and historic, so every job has a wrinkle. The unusual is an everyday occurrence,” says Susanne’s father Stephen. (He and his brother Philip co-owned the business for many years and have recently moved into an easier pace of semi-retirement.)

Take the three-story, two-family brick residence that Stephen encountered in Auburndale, one of Newton’s historic villages. When called to the scene, he walked into a home with 100-year-old cast iron radiators upstairs.

Down in the basement stood two large cast iron boilers. Originally installed in 1890, these coal-burning behemoths had since been converted to use oil. Their big pot bellies, however, were still generously wrapped in white asbestos.

Stephen knew he had stumbled upon two “snowman” boilers. “Believe it or not, when I was a 12-year-old kid my Dad paid me to wrap boilers like these in asbestos.

“We’d surround them with chicken wire, then we’d apply a mixture of asbestos and plaster of paris to make the asbestos stiff. It took three coats. The last coat we’d make smooth. Then we’d whitewash the insulation and paint the boiler doors black. The finished job looked really sharp.”

Snowmen liquidated

He continues: “These days, replacing snowman boilers is a hassle. An asbestos abatement company has to come and remove the coating. They do a clean-air check to certify that there are no loose asbestos particles. Then we can finally go to work.”

On this job, the snowmen were replaced by a Burnham Series 204A and a 205A cast iron gas boiler. The multiple-section boilers provide the heat input needed to handle the hundreds of gallons of hot water required by the system, with the larger, five-section boiler supplying the second- and third-floor apartments. Both units employ an atmospheric draft design.

“These boilers are completely factory assembled and fire tested,” notes Stephen. “So after the old boilers were removed, we hand-trucked them into position and started work on the piping.

“This old house used a gravity-fed hot water system. Typically we’re able to modernize these systems by adding a circulator and some valves.”

Strange sightings

The firm has encountered other strange hot water systems. Stephen recalls a church boiler with a huge, 6-in. main coming from the top of the boiler and running all the way round to the bottom.

“Two pipes tapped into the main. The first was a supply pipe that pulled hot water from the top of the main. The second was a return pipe that tapped into the side of the main. As the hot water rose into the supply pipe from the main, the cooler, heavier water entered the main’s bottom, and around and around it goes.

“They simply engineered a way to take advantage of the rising and falling motion of water as it heats and cools to circulate the hot water without a pump,” says Stephen. “And it works.”

He’s also encountered the opposite piping method. Stephen recalls the home where the main ran up and around the attic.

“There was an expansion tank up there. As a supply, they used a single pipe off the main which dropped down through the floors. As the water cooled in the supply piping, it passed through the tiers of radiators on each floor. Finally, the cooling water circulated through the first-floor radiators and was pulled back into the boiler by the action of the hot water rising in the main.

“Perhaps having the hottest water in the attic isn’t the most energy efficient idea,” interjects his daughter; “but those old boilers had plenty of water content, so there was enough hot water to go around.”

The firm has also handled virtually every type of residential steam heating system found in Boston — one-pipe, two-pipe, vacuum, vapor, steam trap, and tea kettle types, where the steam goes up the same pipe used by condensate as it drips down.

Star-spangled piping

“We’re careful not to oversize steam boilers,” notes Susanne, “especially a one-pipe system. If you undersize it, it’s just not going to work. And with oversizing, the quantity of rising steam won’t let the condensate fall.

“When the condensate is forced back up, that’s when you’ll hear the pipes play the Star-Spangled Banner — rat-a-tat-tat, ping-bang-boom.”

In addition to proper sizing, the contractor’s technicians make sure check valves are in the right place in the return.

“And we’re careful that new steam boilers are blown down and filled with clean water,” adds Susanne. “We also recommend annual water treatment.”

“We’re rarely surprised by what we find,” adds Stephen. “Every job is different.” And from the contractor’s storehouse of experience, they know to give each customer unique treatment.

“My father used to say we don’t have customers,” Stephen concludes. “No one is obligated to hire us. They only favor us with their business. We’ve got to work hard to keep that business and their loyalty no matter what situation we encounter.”

For more information on Burnham boilers, contact that company at 717-397-4701; 717-293-5827 (fax); www.burn ham.com (Web site).