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NJM Mechanical & Contracting

Plumbing, Heating & Cooling In Commack

Commack is one hamlet in two towns. North of Jericho Turnpike, Townline Road is literally the line — Huntington to the west, Smithtown to the east — and it decides which building department your permit goes through.

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Commack

Plumbing, Heating & Cooling In Commack

Commack is one hamlet in two towns. It straddles Huntington and Smithtown, and north of Jericho Turnpike the boundary is Townline Road itself — west of it you are in Huntington, east of it you are in Smithtown. The split goes back to overlapping land grants in the 1650s and 1670s, and the junction of Jericho Turnpike and Townline Road is still called Commack Corners. Five school districts serve parts of the hamlet for the same reason.

For a homeowner this is not trivia, it is which forms your job goes on. Smithtown issues separate permits for plumbing, for heating, for gas and for air conditioning, and requires a gas pressure test permit with a fee per meter per test. Huntington runs plumbing and gas piping permits together through its Department of Engineering Services. Same hamlet, same street in some cases, two entirely different processes.

The housing is consistent even where the government is not. Around eighty-two per cent of Commack homes were built between 1950 and 1979, with the 1960s alone accounting for forty-four per cent, and the median house dates to 1964. In 1954 Commack had one school and under eight hundred people; by 1966 it had seventeen schools and thirty-eight thousand residents. Everything went in at once, and sixty years later it comes due at once.

24/7 Emergency ServiceLicensed & Insured
  • Master PlumberLicensed to pull permits
  • TASK 86/87Certified for gas work
  • Navien NSSFactory-trained on tankless

22+ years on Long Island · Plumbing, heating, cooling, gas and contracting under one roof

Before you call

Two kinds of visit. You’ll know which before we come.

We don’t charge to quote a job. We do charge to find a problem nobody has identified yet. Which one you need — and what it costs — gets agreed on the phone, so nothing about the cost is a surprise on the doorstep.

Estimate visitNo charge

You already know what you want done

A boiler replaced, a bathroom rebuilt, a gas line run. We come out, look at the job and give you a number.

No obligation
Diagnostic visitQuoted on the call

Something has failed and nobody knows why

A licensed technician and the time to find what has actually gone wrong. One rate across plumbing, heating, cooling and gas, and one number to reach us on — there is no separate line to find at midnight. You get the figure before anyone is dispatched, and after-hours, weekend and holiday work is quoted the same way.

The rate you are told is the rate

You get the number on the phone, before anyone is dispatched, and it is what you are charged when the technician arrives. One rate across all four trades — plumbing, heating, cooling and gas.

What it pays for

A licensed, insured technician carrying the certifications the work needs, and the time to find what has actually failed — not a quick look and a guess.

Watch for the bait and switch

A call-out advertised at almost nothing gets recovered once someone is standing in your basement. Get the number before anyone travels — from us, or from anyone else you call — and hold them to it when they arrive.

Financing on larger jobs

A boiler that fails in January is not a purchase anyone planned. Financing is available on the big-ticket work, so a system replacement does not have to come out of savings in one go.

What it is normally used for

Boiler, furnace and water heater replacement, a full air conditioning system, a whole-house repipe, sewer and water main work, and larger contracting jobs — kitchens, bathrooms, dormers and extensions.

When to bring it up

At the estimate, before anything is scheduled. It is worth asking even if you think you will not need it, because knowing it is there changes what you are willing to consider fixing properly.

What it does not change

The price of the job. The quote is the quote whether you finance it or not — and on a straightforward repair it is usually not worth the paperwork. We will tell you which one you are looking at.

Financing provided throughSynchronyCredit is extended by Synchrony. Subject to credit approval.
Call 631-587-0085Not sure which one you need? Call and describe it — we will tell you before we book anything.
The Second Replacement

Whatever You Are Replacing Was Probably A Replacement Too

The median Commack house dates to 1964. Almost nothing mechanical in it is original — so the question worth asking is not how old the system is, but why the last one only lasted twenty years.

A house built in the mid-sixties has had its heating changed at least once, usually in the nineties or early two-thousands, and often its air conditioning twice. That earlier replacement is now itself at the end of its life, which is why so much of what we are called to in Commack is a system that is neither original nor new.

And that is the useful clue. Equipment that lasts fifteen or twenty years when it should have lasted twenty-five is usually telling you something about the installation rather than the machine. The three that come up again and again here are the same three: it was sized from the label on the old unit instead of from the house, the ductwork was never touched so the new system inherited the old problem, and the airflow was never balanced afterwards so half the rooms were wrong from day one.

None of those get fixed by buying another box. They follow you to the new system, and in twenty years the next contractor will be standing in the same basement having the same conversation. So before we quote a replacement in a house of this vintage we would rather look at what the last one actually got wrong — because if the answer is the ducts, then the ducts are the job and the equipment is the easy part.

Where this bites hardest is cooling. These houses largely got air conditioning added after they were built rather than designed in, which is why so many Commack homes have a system that cools the downstairs beautifully and leaves the bedrooms warm. That is almost never the unit. It is duct sizing, return air, or a system chosen to match a number somebody wrote down in 1998.

Quick Rules Of Thumb

  • A system that died at fifteen years is telling you about its installation
  • Sizing taken from the old unit repeats whatever mistake was made last time
  • New equipment on old ductwork inherits the old problem
  • Rooms that were never right are an airflow question, not an equipment one
  • We would rather price the ducts honestly than sell you a bigger box
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What We Do Here

Services In Commack

Repipes & Leak Repair

Supply piping from the 1950s and 60s is at the end of its design life. We locate leaks properly before opening anything, and repipe when the repairs start arriving in threes.

Drains, Sewers & Septic Lines

Commack is not in a county sewer district, so drainage problems here are as often the system as the pipe. We diagnose which before anyone starts digging.

Boilers & Furnaces

Heating plant in a 1960s Commack house has usually been replaced once already. Installation, service and honest repair-or-replace advice on both.

Central Air & Ductless

Full systems and ductless mini-splits for additions, converted garages and the upstairs rooms the original system never really reached.

Gas Lines, Conversions & Pressure Tests

TASK 86/87 certified. On the Smithtown side a gas pressure test carries its own permit, per meter per test — worth building into the schedule rather than discovering on the day.

Water Heaters & Tankless

Replacement and installation across gas, oil and propane, including high-efficiency tankless. Navien NSS certified.

Kitchens & Bathrooms

Renovations where the plumbing, gas and mechanical are one licensed team rather than three trades pointing at each other.

24/7 Emergency Service

Every day of the year. Commack Road runs from Deer Park Avenue in North Babylon straight up to Commack — about thirteen miles on one road.

Common Questions

Frequently Asked Questions

My air conditioning cools downstairs but never the bedrooms. Do I need a bigger system?

Almost certainly not, and a bigger one will often make it worse. In a Commack house that got its air conditioning added after it was built, uneven cooling is nearly always ductwork — undersized runs, not enough return air, or a system balanced for the ground floor and never for upstairs. An oversized unit short-cycles, which cools the air fast without removing the humidity and leaves the house cold and clammy. We look at the airflow before quoting equipment, because that is the cheaper conversation and quite often it is the whole answer.

My boiler is only about twenty years old and it has failed. Was it a bad unit?

Possibly, but more often it was a good unit that was set up badly. Equipment that gives fifteen to twenty years where it should have given twenty-five is usually telling you about the installation — wrong size for the house, near-boiler piping done quickly, or a distribution system nobody touched. That matters right now, because if we simply put the same thing back in the same way you will be having this conversation again in twenty years. It is worth half an hour working out what actually went wrong first.

Can you install air conditioning in a house with no real ductwork?

Yes, and in a lot of 1960s Commack houses ductless is the better answer rather than the fallback. One outdoor unit runs several indoor heads, each on its own thermostat, with no ducts at all — which suits the rooms these houses always struggle with, the converted space over the garage and the bedrooms at the end of a long run. It heats as well as cools. We install both ducted and ductless, so there is no reason for us to push one over the other.

Do you do renovation work in Commack as well?

Yes — kitchens, bathrooms, dormers and extensions, with the plumbing, gas and HVAC handled by the same licensed team rather than subcontracted out. On a house of this age that is the part that usually goes wrong: the trades are fine individually and the project stalls at the handover between them. One schedule and one company accountable is the whole argument.

Which trades do you lead with out here?

Cooling and contracting, and the service and repair work that keeps a sixty-year-old house running. Commack is a long way from being our closest town, so what brings us out here tends to be the jobs where doing all four trades under one roof genuinely saves somebody a headache — a renovation, a cooling system that has never worked properly, or a house where three things need doing and nobody has put them in an order. Call and describe it and we will tell you honestly whether we are the right people for that particular job.

Am I in Huntington or Smithtown?

North of Jericho Turnpike, Townline Road is the boundary — west of it is the Town of Huntington, east of it is the Town of Smithtown. Commack School District uses the same line. If you are south of Jericho Turnpike it is worth confirming rather than assuming. Call 631-587-0085 with the address and we will tell you which town you are in before anything is filed.

Does the permit process differ between the two towns?

Yes, meaningfully. Smithtown issues separate permits for plumbing, heating, gas and air conditioning as distinct categories, and requires a gas pressure test permit with a fee charged per meter per test. Huntington covers plumbing and natural gas or LP piping under one permit regime through its Department of Engineering Services. Both towns license their own plumbers, and the county-wide Suffolk County licence does not apply in either, because both have their own legislation.

Is Commack on public sewer?

No. Suffolk County publishes sewered-areas maps for both Huntington and Smithtown, and no Commack sewer district appears on either. Homes here are on cesspools or septic systems, with scattered private treatment plants serving specific condominium and commercial developments. County-wide, roughly three quarters of Suffolk properties rely on on-site systems.

Is there a grant to replace my cesspool?

Yes. The Suffolk County Septic Improvement Program covers properties served by a septic system or cesspool and not connected to a sewer, which includes Commack. It grants money toward a nitrogen-reducing replacement system, with the balance financeable over fifteen years, and there is additional support for low-to-moderate income applicants. The amounts have been revised several times, so check reclaimourwater.info for what is current rather than relying on a figure you read somewhere.

Where does Commack get its water?

The Suffolk County Water Authority, which covers Commack across two of its distribution areas. SCWA publishes an annual water quality report by area, and has built advanced oxidation treatment across the Town of Huntington to remove 1,4-dioxane. If you are considering filtration, read the report for your own distribution area first.

How far is Commack from your shop?

About thirteen miles, and almost all of it on one road. Commack Road is Suffolk County Route 4, and its southern end is Deer Park Avenue in North Babylon, a few minutes from our shop on Magro Drive. Twenty to twenty-five minutes in normal traffic.

Service Area

Proudly Serving Long Island and Surrounding Areas.

Based in North Babylon, working across both counties — close enough to get there fast, local enough to know the housing stock and the permit offices.

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What Long Island Says

Reviews From Homes & Businesses We've Served

5 out of 5 stars

The experience I had with with NJM Mechanical & Contracting was a pleasant one. I had the pleasure of doing business with Neil. The work I had done was a basement entrance to my yard and it came out wonderful. The work performed as well as the communication is 10/10.

Nick UrziaJune 2026
Reviewed on Google

5 out of 5 stars

Neil has handled all my A/C needs over the years. He's very communicative and open about service charges. He never steers you wrong

Jim JacksonMay 2026
Reviewed on Google

5 out of 5 stars

As always, Neil is a pleasure to have as my plumber. He is so professional and knowledgeable. I wouldn't use anyone else! I highly, highly recommend him.

Fritzi R.May 2026
Reviewed on Housecall Pro

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