Request Service

Chelmsford Furnace Replacement

Chelmsford Furnace Replacement

  • Furnaces
  • Heating
MillTown Plumbing HVAC Contractor - Heating Contractor & Repair in the Merrimack Valley - serving Chelmsford, Lowell, Billerica, and the surrounding areas

Heating a home during the colder months is necessary, and no one wants to be caught off guard with a broken furnace when the temperature drops. However, a furnace doesn’t last forever, and homeowners need to recognize when they need furnace replacement. This Chelmsford, MA client had an old oil furnace that was fed by an oil tank in desperate need of replacement due to rotting mounts. While they could have replaced their oil tank and their furnace with another oil-fed unit, they opted for a more efficient gas furnace with the help of MassSave loans which MillTown Plumbing helps to facilitate. This blog will guide you through the differences between oil and gas furnaces, the signs your furnace needs replacement, the benefits of replacing it, and the furnace replacement process itself of this Chelmsford, MA client.

Furnace Replacement: Gas vs. Oil

Oil furnaces have been a staple for many older homes. They produce high BTUs, which means they provide substantial heat. However, oil furnaces often come with higher fuel costs, and they require a storage tank that can take up valuable space. These tanks can also decay over time, creating an additional maintenance concern – exactly what happened to this Chelmsford client.

Oil Furnaces:

  • High BTU output
  • Higher fuel costs
  • Requires storage tank
  • Storage tanks can decay over time
MillTown Plumbing Furnace Replacement in Chelmsford Old 80% Oil Furnace
Old 80% Oil Furnace

Conversely, gas furnaces are more energy-efficient and environmentally friendly, often leading to lower monthly heating costs. Plus, natural gas is readily available in most urban and suburban areas, eliminating the need for on-site storage.

Gas Furnaces:

  • More energy-efficient
  • Lower monthly heating costs
  • Natural gas is readily available
  • No need for on-site storage

Signs You Need a Furnace Replacement

When it comes to recognizing the signs that your furnace needs a replacement, start by checking its age. The average lifespan of a furnace is 15 to 20 years. If your furnace is older than this, it’s probably time for a replacement. Additionally, look for signs like increased heating bills, which may indicate your furnace is losing its efficiency. Constant repairs, inconsistent temperatures, strange noises, or visible signs of rust or cracks are also indicators that a replacement might be due. Symptoms your furnace needs a replacement include:

  • Furnace age exceeds 15-20 years
  • Increase in heating bills
  • Frequent need for repairs
  • Inconsistent temperatures
  • Unusual noises
  • Visible signs of rust or cracks
MillTown Plumbing Furnace Replacement in Chelmsford Rotted Oil Tank Mount
Rotted Oil Tank Mount

Benefits of a Furnace Replacement

Replacing an old furnace with a new one comes with several benefits:

  • Lower energy bills
  • Increased comfort
  • Better indoor air quality
  • Longer lifespan
  • Lower maintenance costs

Firstly, newer models are more energy-efficient, which means they will heat your home more effectively while reducing your energy bills. Secondly, modern furnaces often feature advancements in technology that enhance comfort and convenience, such as smart thermostats and variable-speed blowers. Lastly, replacing a deteriorating furnace can save you from the discomfort and expense of a sudden breakdown during the cold season.

Chelmsford, MA Furnace Replacement Process

This Bedford, Massachusetts client would be replacing their 80% furnace and unenclosed air conditioning system with a 95% furnace and Bosch heat pump. The furnace would net 15% more efficiency than the previous furnace (80% vs. 95%). The furnace is supported by the heat pump, utilizing the heat pump until outside temperatures dropped below 30 degrees Fahrenheit.

A 95% furnace is a great choice for Bedford homeowners due to its energy efficiency when temperatures are moderate, and its ability to still perform in the extreme cold.

Removing the Old Furnace

The first step in the Chelmsford, MA furnace replacement was removing the old, less efficient 80% oil furnace. The process was initiated by detaching the oil supply line. Due to the furnace being shut off at the valve and the line being gravity-fed, there were no leaks during this procedure.

MillTown Plumbing Furnace Replacement in Chelmsford Oil Supply Line to Furnace
Oil Supply Line to Furnace

Subsequently, the electrical power to the furnace was turned off at the fuse box. A safety step verified with a test light to ensure there was no power to the unit.

MillTown Plumbing Furnace Replacement in Chelmsford Disconnecting Electrical from Furnace
Disconnecting Electrical from Furnace

Other procedures included removing the high limit, which is a safety device that shuts off the furnace if the ductwork temperature gets too high.

MillTown Plumbing Furnace Replacement in Chelmsford Duct Mount High Limit Humidistat Removal
Duct Mount High Limit Humidistat Removal

Lastly, the screws connecting the old furnace to the existing ductwork were removed, and the old furnace was safely taken off the foundation. The furnace replacement would use the same foundation.

MillTown Plumbing Furnace Replacement in Chelmsford Ductwork Removed from Old Furnace
Ductwork Removed from Old Furnace
MillTown Plumbing Furnace Replacement in Chelmsford Old 80% Oil Furnace Removed
Old 80% Oil Furnace Removed

Preparing for the Furnace Replacement

Once the old furnace was removed, the process of preparing for the new gas furnace began. This involved patching and leveling the existing ductwork to ensure a smooth furnace replacement process.

MillTown Plumbing Furnace Replacement in Chelmsford Leveling Ductwork
Leveling Ductwork
MillTown Plumbing Furnace Replacement in Chelmsford Old Ductwork Patched
Old Ductwork Patched

The installation team also drilled holes in the exterior to accommodate the new intake and exhaust flues. Since the flues needed to be 3” due to length and number of 90-degree elbows, the measurements had to be precise.

MillTown Plumbing Furnace Replacement in Chelmsford Holes Cut for Flue Access
Holes Cut for Flue Access

The next step was deciding the placement of the furnace replacement for this Chelmsford homeowner. We install furnaces according to manufacturer code, so ensuring it had 30” of space in front was critical.

An access hole was cut into the side of the furnace and a filter housing was attached to it.

MillTown Plumbing Furnace Replacement in Chelmsford Hole Cut in Replacement Furnace for Filter Housing
Hole Cut in Replacement Furnace for Filter Housing

The furnace was then placed on a cinder block foundation and leveled using rubber feet as shims.

MillTown Plumbing Furnace Replacement in Chelmsford Leveling Replacement Furnace
Leveling Replacement Furnace

Installing the Replacement Furnace

The new Bosch 96% furnace was then ready for installation. A two-stage transition for the supply and return ducts was custom-made, and notches were cut into the corners to allow for ease of installation.

MillTown Plumbing Furnace Replacement in Chelmsford Second Ductwork Transition
Second Ductwork Transition

This was followed by sealing the transitions with foil tape to improve efficiency.

The intake and exhaust flues were cut to size and installed, being sealed together using PVC cement.

MillTown Plumbing Furnace Replacement in Chelmsford Furnace Exhaust and Air Intake
Furnace Exhaust Flues, Exhaust and Air Intake

Following code, the flues were hung at a pitch and supported by straps drilled into the wooden beams and ductwork.

MillTown Plumbing Furnace Replacement in Chelmsford Drilling Hangers for Furnace Flues
Drilling Hangers for Furnace Flues

The gas line was rerouted to the furnace, a crucial step as the gas line’s diameter had to support the furnace and the other appliances using the same line. That demand is measured in BTUs, so MillTown’s code enforcer verified that the gas line was sufficient.

MillTown Plumbing Furnace Replacement in Chelmsford Plumbing Furnace Gas Pipe
Plumbing Furnace Gas Pipe

Tech-Tip: If the gas line demand was too high, the furnace pilot light could fail to ignite, causing a no-heat issue, and causing issues with other appliances on the same line.

The electrical was wired up, including a GFCI outlet to prevent issues if there was ever an instance of moisture, per code. The condensate pump was plumbed to the furnace and plugged into this outlet.

After installing a replacement furnace, MillTown wires up and installs a new thermostat. We then test for functionality.

MillTown Plumbing Furnace Replacement in Chelmsford Complete Furnace Replacement in Chelmsford, MA
Complete Furnace Replacement in Chelmsford, MA

Furnace Replacement: How Mass Save Can Help

Mass Save is an initiative sponsored by Massachusetts’ natural gas and electric utilities and energy efficiency service providers. They offer a range of services, including no-cost home energy assessments, rebates on energy-efficient appliances, and 0% financing for energy efficiency improvements. In this Chelmsford client’s case, the homeowners were able to finance their gas furnace replacement through Mass Save, making the project much more financially feasible.

As a registered Mass Save contractor for HVAC, MillTown Plumbing has met strict standards for quality and service. We are committed to providing our customers with the best service in Chelmsford and the Merrimack Valley. We are proud to be part of a program that helps homeowners and businesses save money while reducing their impact on the environment. See how MillTown can help save you money through Mass Save!

Chelmsford, MA Furnace Replacement Contractor

For Chelmsford residents, choosing a trusted furnace replacement contractor can make all the difference in a smooth and efficient installation process. Our local HVAC experts are well-versed in the regulations and building codes and have a solid understanding of the various heating options suitable for the Massachusetts climate. With their expertise, you can rest assured that your new furnace will provide comfortable, efficient heat for your home for years to come.
Here at MillTown, we provide cost-effective, permanent solutions to keep your home in tip-top shape. We commit to your satisfaction and offer high-quality, same-day service. Our technicians are clean, courteous, and respectful of your home. It is why Massachusetts and New Hampshire homeowners have trusted us for over 35 years. Contact us today if you are a local Chelmsford homeowner interested in furnace replacement, repair, or maintenance!

Samuel BroadwaterSamuel Broadwater
19:05 02 Aug 23
I cannot recommend Milltown based on their practices and up charged quote they gave me. To even get a quote, they charge you $85 to come out and evaluate what needs to be done. I needed a hybrid water heater replacement, installation, and piping that had to be brought up to code.Of the 12 contractors who quoted the job, Milltown was the highest by far at $6,991, which is about double the average ($3,400) and $1900 over my second highest quote. This outrageously inflated price included the $750 state rebate for a water heater priced at $1,349. The $6,392 remaining is for the rest of the associated parts and labor.As for the $85 evaluation fee, it completely feels like a scam. If you choose their inflated service, they put the $85 fee towards the service cost but if not, you’re left with that bill. To me this feels as if they are preying on the “sunk cost fallacy” so you don’t waste your $85. Either way, they get a profit; it’s a win-win situation for them. There is no way I can recommend them. There are cheaper options in the area for the same work. Please be diligent and learn from my mistakes. Don’t get a quote from them. Don’t hire their services. I hope this will save you the headache.
Patricia SawyerPatricia Sawyer
18:40 27 Jul 23
I had a badly blocked shower drain. Called Milltown in the morning, and the call was handled in a friendly and professional manner. The call-back to schedule a next-day appointment was also quick, pleasant, and courteous. A subsequent call informing me that my appointment could be squeezed in same day was most welcome, and when the plumber arrived, she quickly and efficiently resolved the issue. Everyone was very pleasant to interact with. Thanks!
Leigh GerowLeigh Gerow
19:51 24 Jul 23
Kenny P. Is a top notch plumber! He arrived on time and was incredibly professional. Our situation was quite unique and he was very patient with our problem. Kenny is an incredible representative of Milltown. He would not give up until he solved our issue- all the while working with a smile and great demeanor. Booties on his shoes, left the sink and area cleaner than it was when he arrived. We are SO greatful to him and will be telling everyone to call Milltown! A++++++ for Kenny !!!!!!!
Michael GailliardMichael Gailliard
16:09 23 Jul 23
The Gentleman Ralph who came to my home and installed the toilet did a Great job! He was very knowledgeable of what needed to be done , and performed the installation efficiently and with superior professionalism. During and after the job was completed Ralph kept me informed of the services of Milltown. No pun intended I was truly " relieved " after completion of the installation.
Alison SicconeAlison Siccone
22:29 19 Jul 23
I've used Miltown several times now. Each technician has been extremely knowledgeable and helpful. They've resolved every issue in a timely manner. Scheduling an appointment is very easy and the answering service is very helpful in getting this accomplished. Highly recommend!!
Feleshia WaltersFeleshia Walters
14:13 19 Jul 23
I got a toilet replacement and the charged me almost 3,000. I won't them to anyone. They're way to expensive and come to find out its still leaking. Like seriously, if your going to charge the most do the job correctly without any mistakes!!!!!!!!! I won't recommend them to anyone. Call a local plumber would be the better option. On top of that they charged me 2,000 for traveling fees, like your located in Chelmsford - Lowell. I couldn't gave you 40 bucks for gas. They pretty much robbed me.
Patrick HowePatrick Howe
15:48 11 Jul 23
Making an appointment was fast and easy. Mike arrived exactly on time, and diagnosed the problem very quickly, but still checked other possibilities just to be sure. On the day of the repair, Mike and his partner arrived again on time, with booties in hand. They introduced themselves, interacted playfully with our curious child, and explained exactly what they would be doing. At the end of the day, they provided a full summary of the work, including many before & after photos. They provided some information on next steps, and emailed everything to me on the spot. 100% will use them again!
Paul WPaul W
18:08 09 Jul 23
The pros are Milltown was very professional. They were clean, prompt and the quality of work was good. The cons are they were VERY expensive. I was able to talk them down by approximately 40% and it'd be better if the initial price were reasonable.
Elaine WinchellElaine Winchell
19:29 29 Jun 23
Matt and his assistant arrived on time and carefully assessed my exhaust fan replacement. As the fan in place was over 10 years old Matt provided me with the different options I had for how to replace the unit and how it would look when finished. We discussed my options and Matt went to work. Unfortunately it meant Matt needed to access the fan from the attic which was extremely hot and pretty much a crawl space. The job was well done, they were very professional and cleaned up when finished. I would definitely recommend Mill Town for professionalism and fast scheduling. And I would absolutely recommend Matt for electrical work!! Thank you Mill Town!
shawn mcinnisshawn mcinnis
01:38 24 Jun 23
I needed my kitchen faucet replaced on Friday as we are entertaining the next day. Milltown responded to my inquiry immediately. Customer service was excellent. The technician was there the next day. He was professional in his manner and extremely friendly. He resolved the problem and provided me with insightful information.In my opinion the price was a high but you get what you pay for so yes I recommend Milltown.Shawn M
David PauplisDavid Pauplis
22:59 21 Jun 23
Outstanding overall experience! They worked with me to meet a critical deadline (thank you Kevin) Great communication, they pick up the phone when i called, return calls promptly, arrive on time as promised and do great work (thank you Josh and Danny) and follow up after the job is completed. I am very happy and will be sure to call them again when i need additional work!
Kevin BowenKevin Bowen
13:43 16 Jun 23
Mathew came to do an electrical safety inspection. He was early, polite and professional. He gave me a fair estimate of work that I need done in my house and was thorough in his inspection - even giving me some extra advice on smoke detectors in my home and explained some issues that I've been having.Definitely will use MillTown again.
Jane SancinitoJane Sancinito
12:31 06 Jun 23
Such a pleasure to work with this competent, knowledgeable, and polite team! They follow through on their promises, handle the issue, and clean up after themselves. I only knew that Milltown did plumbing, but I’ll be using them to handle everything I can now that I see their full range of services! Shout out to Izzy and Kenny for being so lovely and helpful!
Webb DicksonWebb Dickson
13:38 11 May 23
I had 2 experiences with Mill Town recently.I had a new gas hot water heater installed in my home and was shocked at the price of $3,000 - but proceeded due to lack of how water. No complaints about the tech, he was considerate and nice. But shortly after the install the safety relief valve started to leak. They came back and put an expansion tank on system which made no sense since one had not been needed in the 25 years we had been there. It continued to leak and they then told me the town water pressure was too high and a pressure reducer would be needed. Again, pressure had been the same over the 25 years we had been there (yes I measure it) - and the town water department confirmed same. I refused to accept that and had to travel. When I returned the leak had stopped so I did not pursue further.2nd experience was have leaky tub drain fixed. The only offered to replace the entire drain and not repair it - a bit disappointed about that. The price was a bit high, but the work was high quality.Milltown has great customer service. I feel their prices are high (why 3 stars only) but they are a premium plumbing service so you know things will be done right.
Roberta MooradianRoberta Mooradian
19:02 09 May 23
I was delighted to have called Milltown Plumbing and Heating into my home to clean and service my furnace for the very first time (with this company). The technician did an exceptional job and was extremely skilled at what he did, explaining the furnace cleaning step-by-step to ensure the owner knew the process. He ran down his checklist and completed all the electrical checks and readings to reassume me that, even though my furnace was an older model, it was still up and running. I would not hesitate to refer friends and family to Milltown Plumbing and Heating moving forward.

Furnace replacement near me:


  • Acton, MA
  • Andover, MA
  • Ayer, MA
  • Ballardville, MA
  • Bedford, MA
  • Billerica, MA
  • Boxford, MA
  • Burlington, MA
  • Carlisle, MA
  • Chelmsford, MA
  • Clinton, MA
  • Concord, MA
  • Danvers, MA
  • Devens, MA
  • Dracut, MA
  • Dunstable, MA
  • Georgetown, MA
  • Groton, MA
  • Harvard, MA
  • Haverhill, MA
  • Hudson, MA
  • Lancaster, MA
  • Lawrence, MA
  • Leominster, MA
  • Littleton, MA
  • Lowell, MA
  • Lunenburg, MA
  • Lynnfield, MA
  • Marlborough, MA
  • Methuen, MA
  • Middleton, MA
  • Newburyport, MA
  • North Reading, MA
  • Pepperell, MA
  • Reading, MA
  • Tewksbury, MA
  • Topsfield, MA
  • Topsfield, MA
  • Townsend, MA
  • Tyngsborough, MA
  • Waltham, MA
  • Westford, MA
  • Wilmington, MA
  • Woburn, MA

New Hampshire

  • Amherst, NH
  • Atkinson, NH
  • Auburn, NH
  • Bedford, NH
  • Brookline, NH
  • Chester, NH
  • Danville, NH
  • Hampstead, NH
  • Hollis, NH
  • Litchfield, NH
  • Londonderry, NH
  • Manchester, NH
  • Mason, NH
  • Merrimack, NH
  • Milford, NH
  • Nashua, NH
  • Pelham, NH
  • Plaistow, NH
  • Salem, NH
  • Sandown, NH
  • Windham, NH

By MillTown Plumbing