Richard Trethewey: The Fourth-Generation Plumber Who Became America’s Most Trusted Home Systems Expert

If you have ever watched a PBS crew tear open a wall to reveal a rat’s nest of old cast-iron pipe, you already know the voice that explains what happens next. For more than four decades, Richard Trethewey has been the person American homeowners turn to when the boiler quits, the radiators clank, or the shower runs cold. He is not a celebrity who learned plumbing for television. He is a licensed master plumber who happened to end up on television, and that order of events explains almost everything about his career.

Who Is Richard Trethewey?

Richard Trethewey is the plumbing and heating expert on the PBS home improvement series This Old House and its long-running spin-off Ask This Old House. He is a licensed master and journeyman plumber in the Commonwealth of Massachusetts, the founder of the training and manufacturer’s representative firm RST Thermal, and a fourth-generation member of one of Boston’s oldest plumbing families.

Born in the mid-1950s and raised in Dedham, Massachusetts, he grew up inside the trade rather than choosing it later. His education happened on job sites during summers and school vacations, alongside his father and the other tradesmen who worked in the family business.

The Family Business That Started It All

The Trethewey story in Boston begins in 1902, when Richard’s great-grandfather and his brother founded Trethewey Brothers in the Roslindale neighborhood. The origin is better than most company histories. The two men were firefighters who started moonlighting as apprentices in what was then a brand-new trade called plumbing.

That side hustle turned into one of the most respected plumbing and heating companies in the city. By the time Richard came along, the business had passed through generations and was being run by his father, Ron, and his uncle, John. Richard represents the fourth generation in the trade, a detail that gets misreported often enough that it is worth stating plainly.

How Richard Trethewey Ended Up on This Old House

In the late 1970s, producer Russell Morash was assembling a home renovation show for WGBH in Boston and needed real contractors. He called Trethewey Brothers. The pitch came with a catch: public television had no money, so the work would be unpaid.

Ron Trethewey said yes anyway. His reasoning was practical rather than visionary. The company was having a good year, and trying something new was not going to sink it. Ron and his brother John appeared on camera during the show’s first season in 1979.

Then came the twist that launched a career. Ron enjoyed the show but not the pressure of performing in front of a camera crew, so after that first season he asked his son to take his place. In 1980, Richard Trethewey became the show’s plumbing and heating expert. Some references date his run as a full-time regular to 1981, but the handoff happened at the end of that first year.

He has held the role ever since, across host changes from Bob Vila to Steve Thomas to Kevin O’Connor, and across a series that has run for more than 45 seasons and earned well over a dozen Emmy Awards.

Four Decades of Explaining the Invisible

What makes Richard Trethewey unusual on television is his subject matter. Carpentry looks good on camera. A finished deck or a restored staircase sells itself. Mechanical systems live behind drywall, under floors, and in basements, and most of them are ugly.

His job has been to make that invisible layer of the house feel understandable and, more importantly, worth spending money on. Over the years he has walked viewers through hydronic heating, high-efficiency condensing boilers, modern plumbing layouts, smart controls, heat pumps, and energy-saving retrofits. He has also spent a lot of airtime on the genuinely hard problem in old-house work: fitting current technology into a building that was designed for coal, gravity, and open flame.

Since 2002 he has also appeared on Ask This Old House, the spin-off built around homeowner questions and house calls, and he was part of This Old House: Trade School, a 2017 series aimed at teenagers that showed what working alongside seasoned pros actually looks like. That last project fits a pattern. Richard Trethewey has been one of the more consistent public advocates for professionalism in the building trades, at a time when the industry has struggled to recruit young people.

Life Beyond the Camera

Television has never been his only job. Richard Trethewey founded RST Thermal, a manufacturer’s representative company that provides training to the skilled trades. The training piece matters to him. A large part of his working life has been spent teaching installers how new equipment is supposed to be sized, piped, and commissioned, which is where most heating systems either succeed or fail.

He has also contributed to This Old House books and magazine content over the years, including guidance on heating, ventilation, and air conditioning for homeowners who wanted more than a 10-minute segment.

The Next Generation of Tretheweys

The family line did not stop with Richard. Both of his sons work in the industry. Ross Trethewey is a professional engineer and the president of TE2 Engineering, and he now appears on This Old House himself as the home technology expert, which makes for one of the few genuine father-and-son pairings in home improvement television. Evan Trethewey is the president of RST Thermal, having taken over leadership of the company his father built.

That is now five generations of Tretheweys in the trades, tracing back to two Boston firefighters with a side business.

Personal Life and Interests

Away from job sites, Richard Trethewey is a sailor. He lives on the South Coast of Massachusetts when he is not living aboard a sailboat in Boston, and he splits his interests between sailing and home renovation, which is a fairly narrow set of hobbies for a man who has spent 45 years fixing houses. He has four grandchildren, whom he describes, with a straight face, as all being well above average. Online he goes by the handle @thisoldplumber, where he has built a following in the tens of thousands.

Conclusion

Plenty of television personalities have passed through the home improvement genre since 1979. Very few have stayed, and almost none have stayed while remaining licensed, working professionals in their field.

The lasting value of Richard Trethewey’s work is not that he made plumbing entertaining. It is that he made homeowners curious about the systems they cannot see, and gave them the vocabulary to ask a contractor a better question. That is a quieter contribution than a dramatic before-and-after reveal, and probably a more useful one.

Also read: Charlie Silva: Biography, Career, This Old House, and Life in Construction

FAQs

How long has Richard Trethewey been on This Old House?

He took over from his father in 1980, after the Trethewey family appeared during the show’s debut season in 1979, giving him more than four decades on the program.

Is Richard Trethewey a real plumber?

Yes. He is a licensed master and journeyman plumber in Massachusetts and a fourth-generation member of the Trethewey plumbing family.

Who are Richard Trethewey’s sons?

Ross Trethewey, a professional engineer who serves as the home technology expert on This Old House, and Evan Trethewey, president of RST Thermal.

What company does Richard Trethewey own?

He founded RST Thermal, a manufacturer’s representative firm that trains skilled tradespeople. His son Evan now runs it.

Where is Richard Trethewey from?

He was born and raised in Dedham, Massachusetts, and still lives in the state, on the South Coast.