What does the Lennox A2L sensor fault code mean?

It means your system's Refrigerant Detection System sensed a change in the air and safely paused the equipment. It can be a harmless nuisance trip or a real leak, so it should be verified before you keep running the system.

Is the A2L sensor code dangerous?

The code itself is a safety feature working as intended. What matters is the cause. Because a nuisance trip and a real leak look the same from the thermostat, the safe step is to have it checked.

How does a smart thermostat work?

Smart thermostats use sensors, algorithms, and Wi-Fi connectivity to monitor and adjust your home's temperature settings based on factors like occupancy, outdoor weather conditions, and user preferences.

Are smart thermostats compatible with my HVAC system?

Smart thermostats are compatible with most heating and cooling systems, including gas, electric, oil, and heat pump systems. However, compatibility may vary based on the specific model and features of your HVAC system. Our team of Specialists can help you determine if you have a compatible system.

Can I install a smart thermostat myself or do I need professional installation?

While some homeowners may be able to install a smart thermostat themselves, professional installation is recommended to ensure proper wiring, compatibility, and setup for optimal performance and reliability. One of the most important steps in installing a smart thermostat is to ensure the proper wires are connected to not cause a short to your system and that you have a common "C" wire available to power the thermostat.

Do smart thermostats work with smart home ecosystems like Alexa or Google Assistant?

Yes, many smart thermostats are compatible with popular smart home platforms like Amazon Alexa, Google Assistant, and Apple HomeKit, allowing for seamless integration and voice control capabilities. Some of our smart thermostats have compatibility with your home's security system as well.

When is the best time to install a smart thermostat?

The best time to install a smart thermostat is before the start of a new heating or cooling season, allowing for immediate optimization of comfort and energy efficiency. Alternatively, incorporating it during HVAC system maintenance or upgrades ensures seamless integration and maximum effectiveness. Installing a smart thermostat also makes sense when seeking to save on energy bills, enhance home comfort and convenience, or during home renovations or smart home upgrades. Proactively installing before seasonal temperature extremes ensures readiness to adjust settings for optimal indoor comfort.

How much does AC repair cost?

AC repair costs near Manchester, NH can range anywhere from $100 for a quick fix to $2,500 for more complex repairs . The price largely depends on what's going wrong — whether it's a minor issue or a major component that needs replacing.

Should I have regular A/C maintenance?

Yes, it's important to have regular maintenance for your central air conditioning system. Regular maintenance can help ensure that your AC unit is working efficiently, which can save you money on energy bills and prevent costly breakdowns. Here are some reasons why you should have regular central air conditioning maintenance: Improved Efficiency: Regular maintenance can help improve the efficiency of your AC unit, which can reduce your energy bills. When your air conditioner is working efficiently, it doesn't have to work as hard to cool your home. Longer Lifespan: Regular maintenance can also help extend the lifespan of your AC unit. By having your system serviced on a regular basis, you can prevent minor issues from turning into major problems, which can help you avoid expensive repairs or the need for a replacement system. Improved Air Quality: A well-maintained AC system can help improve the air quality in your home by reducing the amount of dust, pollen, and other allergens that circulate through your home. Cost Savings: By having regular maintenance, you can catch minor problems early, before they turn into major issues that require costly repairs. This can save you money in the long run. Overall, regular central air conditioning maintenance is a smart investment that can help ensure your system runs efficiently and effectively for years to come. It's recommended that you have your system serviced by a professional at least once a year.

What to do if my A/C stops working?

If your central air conditioning system stops working, there are a few things you can do to troubleshoot the problem before calling in a HVAC tech. Here are some steps you can take: Check the thermostat: Make sure the thermostat is set to the right temperature and is working properly. If the thermostat is not working, your AC may not turn on or off at the right times. Check the air filter: A dirty air filter can restrict airflow and cause your AC to stop working. Check the air filter and replace it if it's dirty. Check the circuit breaker: If the circuit breaker that controls your AC has tripped, reset it and see if that fixes the problem. Check the condenser unit: The condenser unit is the outdoor unit that houses the compressor. Check to see if the unit is running and if the fan is spinning. If the unit is not running, check to see if there is power going to the unit. If these steps do not fix the problem, it's time to call in a AC contractor. Our team can diagnose the issue and make the necessary repairs to get your AC up and running again. It's important to have a Specialist handle any repairs or maintenance on your central air conditioning system to ensure that it's done correctly and safely.

Can I clear the Lennox A2L sensor code myself?

The code sometimes clears once the air around the sensor is clear, but that does not tell you what set it off. Repeatedly clearing it can mean running the system with an unaddressed leak, so we recommend a quick professional check instead.

Why is my AC system blowing warm air?

If your AC is blowing warm air near Manchester, NH, it's a clear sign something’s off — and it could be more than just a quick fix. Common culprits include low refrigerant levels, clogged or dirty air filters, a faulty thermostat , or even electrical issues within the system.

What should I do if my furnace stops working?

If your furnace stops working, first check the thermostat settings, ensure the circuit breaker hasn't tripped, and verify that the furnace's power switch is turned on. If these basic steps don't resolve the issue, it's time to call a professional for furnace repair.

Why is my furnace making strange noises?

Strange noises such as banging, rattling, or squealing can indicate various issues, including loose components, a failing blower motor, or a problem with the ignition system. It's best to have a professional diagnose and repair the issue to prevent further damage.

How often should I have my furnace serviced?

It’s recommended to have your furnace serviced at least once a year, ideally before the colder months set in. Annual furnace maintenance ensures the system is running efficiently, reduces the risk of breakdowns, and extends its lifespan. Regular servicing helps identify potential issues before they become costly repairs. If your furnace is older or you use it heavily during the winter, more frequent checks might be necessary. Scheduling furnace service each fall is a great way to ensure peak performance and lower energy costs.

Why is regular furnace maintenance important?

Regular furnace maintenance is crucial for several reasons. First, it ensures your furnace operates efficiently, which can help reduce energy bills . Second, it helps extend the lifespan of the system by preventing wear and tear on vital components. Third, routine maintenance identifies potential issues early, allowing for repairs before they lead to more expensive breakdowns. Additionally, keeping the furnace clean and well-maintained can improve your home's indoor air quality by reducing dust and allergens. Overall, furnace maintenance provides a safer, more reliable, and cost-effective heating system.

What does it usually mean when a furnace is running but not producing heat?

If the furnace is running but not producing heat, that means we have an issue with flame. It could be a faulty (or properly tripped) safety device that's protecting the system from running, it could be a bad gas valve, or ignitor. If the furnace turns on and you hear clicking but no airflow and no heat, that means we have a different issue - usually something with the blower motor or maybe the control board.

Can something as simple as a dirty filter cause furnace problems in winter?

Yes, that can absolutely be the cause. If you have a dirty filter, it is clogged up, and the furnace is struggling to "breathe". Think of trying to breathe yourself through a straw, and then you pinch that straw. If the furnace can't breathe, it's going to trip on what we call "high limit," where the furnace wants to protect the heat exchanger from overheating. Make sure you have no air restrictions and then reset the furnace... it will need some time to cool down.

How much does it cost to replace my home AC system?

Expect to invest between $5,500 and $15,000 in and around Manchester, NH. This range reflects the many options available to fit your home’s size, energy needs, and comfort preferences. Your final cost depends on key factors like the unit’s cooling capacity, energy efficiency rating, the condition of existing ductwork, and any smart upgrades you choose.

What is the warranty on the system?

New Hampshire homeowners should ask about the warranty on the system and what it covers. A longer warranty can provide peace of mind and protect against unexpected repair costs. At GSMS, we're proud to offer our WOW Warranty where we will match the manufacturer warranty on our labor.

What size AC system do I need?

It's important to choose the right size system for your home based on factors such as square footage, insulation, and climate. At GSMS, our Project Specialists will perform a load calculation to determine the appropriate size for your home.

How do you tell a false alarm from a real leak?

We run a leak search using a specialized tool that sniffs for refrigerant, confirm the system's refrigerant levels, and test the sensor itself. Those checks tell us whether it is a nuisance trip, a real leak, or a faulty sensor, which is not something you can determine from the thermostat.

How long does an AC system last in NH?

The lifespan of a central air conditioning system can vary depending on factors such as the quality of the equipment, how well it's maintained, and how frequently it's used. Generally, a well-maintained central air conditioning system can last between 12 to 15 years. However, some factors can impact the lifespan of a central air conditioning system. For example, if the system is not properly installed, if it's used excessively, or if it's subjected to extreme weather conditions, it may have a shorter lifespan. It's important to keep in mind that regular maintenance can help extend the lifespan of a central air conditioning system. We recommend scheduling annual maintenance checks with a professional HVAC contractor to ensure the system is in good working order and to address any potential issues before they become major problems.

What to do when my furnace is not turning on?

There are a few things you as a homeowner can safely check before you make the call to GSMS. If your system has one, make sure to check the Emergency Shut-Off switch didn't get flicked by accident. This switch is usually located right next to your heating system or in your staircase walking down to your basement. Batteries! Check your thermostat has fresh batteries in it… this truly can be a culprit sometimes. Ensure you have fuel to feed your system. If those are all verified and you're still having an issue, it's best to reach out to GSMS to perform a complete diagnosis.

What type of heating system do I have?

Here in New Hampshire, we have many methods of heating our homes and businesses. First, you either have a gas (propane or natural gas) system or a oil system. This is the type of fuel you purchase to heat. The second part is you either have a forced air or forced water system. A forced water system, also known as a boiler, uses radiators/baseboards/radiant floor to heat your spaces. A forced air system, also known as a furnace, uses ductwork to blow air into each room. Our heating specialists are certified & trained to work on all types of heating systems!

What is the average cost of furnace installation in New Hampshire?

The average cost of furnace installation in New Hampshire typically ranges from $2,500 to $6,500 . Factors influencing the price include the type of furnace (gas, electric, or oil), the size and efficiency rating, and the complexity of the installation. Additional costs may arise from necessary modifications to ductwork or electrical systems. Labor costs in New Hampshire can also vary based on the contractor’s experience and location. It's advisable to obtain multiple quotes for a more accurate estimate tailored to your specific needs.

How can I ensure my furnace operates efficiently after installation?

To ensure your furnace operates efficiently after installation, follow these key steps: Schedule regular maintenance : Have a professional technician perform annual inspections and tune-ups. Change filters regularly : Replace air filters every 1-3 months to maintain optimal airflow and efficiency. Use a programmable thermostat : Set your thermostat to adjust temperatures based on your schedule, reducing unnecessary energy use. Seal ducts and air leaks : Ensure ductwork is properly sealed and insulate areas around doors and windows to prevent heat loss. Monitor performance : Keep an eye on your furnace's performance and address any unusual noises or issues promptly.

How long will my furnace system last?

The lifespan of your home’s systems depends heavily on how well they are maintained. Typically they last anywhere between 15–20 years

When do I need to replace my water heater?

Determining when to replace your hot water heater is a near-impossible task. We always say once your tank reaches 10 years old, any remaining use from it is a great risk. Making sure your tank is installed correctly is a big contributor to a long lifespan. Poor water quality in communities such as Merrimack does not help either! How often you use your water heater can also shorten or extend its lifespan.

Is a tank or tankless water heater better?

Tank versus tankless water heaters . A new-aged yet very important question to consider when replacing your hot water heater. Depending on your home, family, and lifestyle can greatly dictate which type of water heater is the best for you. Our team is more than happy to walk you through each system's pros and cons to help you make an educated choice.

How long will my traditional tank system last?

The lifespan of your home’s systems depends heavily on how well they are maintained. 6–12 years (we often see cheaper builder-grade tanks start failing as early as year 6!)

What brand of whole-home humidifier does GSMS install?

We install Aprilaire exclusively. It's the same design Lennox uses in its Healthy Climate product line, and we've found it to be the most reliable, best-stocked option for New Hampshire homes.

Why did the code appear when nothing seems wrong?

These sensors are very sensitive and can react to fumes from cleaning products, paint, or new flooring. That is a common and harmless cause, but it is still worth confirming.

What's the difference between a bypass and a steam humidifier?

A bypass humidifier uses your furnace's heat to convert water into vapor and needs no electrical hookup. A steam humidifier generates its own vapor and needs a dedicated outlet. The right choice usually comes down to your home's square footage. See our full comparison .

Can I install a whole-home humidifier with a mini-split or boiler system?

No. Whole-home humidifiers require a forced-air duct system to distribute moisture through your home.

What humidity level should I set my humidifier to?

We recommend 35 to 45 percent for most NH homes. The 800LC's automatic dual-sensor control reads outdoor temperature and adjusts on its own, so for normal trips and weekends away, it's best to set it once and let it run. If you're leaving for an extended stretch, like heading south for the winter, that's a different conversation, worth asking your Specialist about at your next visit.

How often does a whole-home humidifier need maintenance?

Once a year. That visit replaces the water panel and confirms your system is set for the season.

How much does a whole-home humidifier cost installed?

Pricing depends on your home's electrical setup and ductwork, but visit our pricing page for current bypass and steam installed pricing.

What's the difference between the In-Duct Purifier and the PureAir?

The In-Duct Purifier uses a UVC lamp and carbon cell to target odors and VOCs, a great option if you already have a solid pleated filter in place. The PureAir adds a MERV-16 filter and photocatalytic oxidation technology on top of that, actually filtering out particles, bacteria, and mold, not just neutralizing odor. It's built for homeowners who want the highest filtration level available.

Is UV air purification safe?

Not all UV light is the same. Standard UV lights can produce ozone, which is harmful to breathe, especially for people with asthma. Both products we install are engineered around this: the In-Duct Purifier produces zero ozone emissions, and the PureAir goes a step further, actively breaking down ozone already present in your home's air.

Can a UV air purifier be added to a mini-split or boiler system?

No. These products require a forced-air duct system to work.

How often does a UV air purifier need maintenance?

Annually, for both products. The In-Duct Purifier needs a new carbon cell and UVC lamp; the PureAir needs a new filter, UVA lamp, and PureAir cartridge.

How long does installation take?

The In-Duct Purifier typically takes a couple of hours and can be paired with a filter upgrade or done on its own. The PureAir installation timeline depends on your ductwork and electrical setup.

Does this mean Lennox systems are unreliable?

No. Leak detection is required on all A2L systems, not just Lennox. The occasional nuisance trip is a side effect of extra-sensitive safety detection, and manufacturers are actively refining it.

How much does a UV air purifier cost installed?

It depends mainly on your home's electrical setup. Visit our pricing page for current installed pricing on both products.

Residential Plumbers Serving Manchester New Hampshire

Name: GSMS - Great Service Makes Sense
Address: New Hampshire, US
Telephone: 603-424-8258
Price range: $$

Local Manchester, NH residential plumbers

GSMS is proud to be your trusted partner for all your plumbing service needs in Manchester, New Hampshire, and the surrounding communities. As a family-owned business with more than three decades of experience (serving homeowners since 1987), our skilled plumbers handle everything from quick repairs to full installations and routine maintenance, always with upfront pricing and the Great Service Promise behind every visit.

Whether it is a dripping faucet, a failing water heater, a running toilet, or a whole-home water quality upgrade, our plumbing Specialists diagnose the problem, explain your options in plain language, and get your home back to comfortable and worry-free.

Let us take care of your plumbing, so you can focus on what truly matters—enjoying a comfortable and worry-free home. Call GSMS today at 603-424-8258 to schedule your plumbing service or contact us online with any questions!

Emergency plumbing services in Manchester, NH

Some plumbing problems cannot wait for a scheduled appointment. A burst or leaking pipe, a water heater dumping water across the basement floor, a frozen pipe in a New Hampshire cold snap, or a fixture that will not stop overflowing can damage your home fast. When that happens, GSMS is ready to help.

Our plumbers respond quickly to urgent plumbing problems and work to stop the damage, find the cause, and get your water running the way it should. We offer emergency plumbing service across Manchester and the surrounding communities, so help is available when you need it most.

Call GSMS for emergencies like:

Burst, leaking, or frozen pipes
Major water leaks and flooding
A leaking or failed water heater
Overflowing toilets or fixtures that will not shut off
A sudden loss of water to your home

While you wait for our plumber, shut off the water supply to the affected fixture, or the main water shut-off if the leak is large, to limit the damage. Then call GSMS at 603-424-8258 and we will get a plumber to you as quickly as possible. Prefer to reach us online? Send us a message, and we will follow up right away.

Water heater services: tank and tankless

Water heater repair

Our plumbers diagnose and repair all types of water heaters, tank and tankless alike. From inconsistent temperatures and discolored water to leaks and strange noises, we restore a steady, reliable supply of hot water. Not sure what is wrong? Start with our guide on what to do when you have no hot water.

Water heater installation and replacement

When your unit is past its prime, we help you choose the right replacement and install it correctly the first time, whether that is a traditional tank or a high-efficiency tankless system. As a Rinnai dealer, we install tankless units built for New Hampshire homes.

Tankless water heater installation

A tankless water heater heats water on demand instead of storing it in a tank, so you get a continuous supply of hot water while freeing up floor space in your utility area. For many New Hampshire homes, it is a smart long-term upgrade.

Endless hot water: the unit heats water as it flows, so you are far less likely to run out during back-to-back showers or a full load of laundry.
Energy and space savings: there is no standby tank to keep hot water around the clock, and the compact, wall-mounted design opens up your basement or closet.
Long lifespan: tankless systems often last 20 years or more, well beyond the typical tank water heater.

As a Rinnai dealer, GSMS installs and services Rinnai tankless systems sized for New Hampshire homes and busy households. Our plumbers handle the sizing, the gas or propane supply, the venting, and the local code, and we service what we install. Ready to go tankless or need a repair? See our tankless water heater installation and replacement page, compare costs on our plumbing pricing page, and ask about 0% financing.

Heat pump water heater installation

A heat pump water heater, also called a hybrid water heater, pulls heat from the surrounding air to warm your water instead of generating all of it electrically. For the right home, it is one of the most efficient ways to make hot water.

High efficiency: a heat pump water heater can use two to three times less energy than a standard electric tank, which shows up directly on your electric bill.
Rebates and tax credits: high-efficiency models may qualify for New Hampshire rebates and federal tax credits, so the upgrade can pay back faster. See our guide to tax credits for NH homeowners.
Best fit: they perform best in a basement, garage, or utility space with enough air volume and moderate temperatures, and hybrid models switch to a backup electric element when hot water demand spikes.

GSMS helps you decide whether a heat pump water heater is the right call for your home and our NH climate, then handles the installation along with the plumbing and electrical connections. Learn more on our heat pump water heater installation page, and see whether a heat pump water heater is worth it in New Hampshire before you decide.

Water heater maintenance

Regular flushing, draining, and pressure checks catch small issues early, extend the life of your water heater, and keep it running efficiently. Ask about bundling water heater maintenance into your Home Club plan.

Kitchen plumbing service

A working kitchen keeps your whole home running. Our plumbers keep every fixture and appliance operating smoothly, from a leaky faucet or a clogged sink to a new dishwasher hookup.

Our kitchen plumbing services include:

Faucet repair and installation
Sink repair and installation
Garbage disposal repair and installation
Dishwasher repair and installation
Water line services

Dealing with a slow or clogged kitchen drain? See the drain cleaner our plumbers actually recommend for kitchen sinks before it turns into a bigger problem.

Bathroom plumbing service

Your bathroom sees more plumbing use than any other room in the house. GSMS handles everything from minor repairs to full fixture installations so it stays comfortable, clean, and leak-free.

Our bathroom plumbing services include:

Toilet repair and installation
Shower and tub services
Bathroom sinks
Vanity plumbing
Pipe repair and replacement

Water quality and filtration

New Hampshire water can carry sediment, hardness, and other contaminants that wear on your plumbing and fixtures over time. GSMS installs and services whole-home water quality systems to protect your home and improve the water you drink, cook, and bathe with.

How much do plumbers cost?

Plumbing costs depend on the job, the parts required, and how complex the repair or installation is. GSMS gives you upfront pricing before any work begins. See our plumbing pricing page for typical costs, or call 603-424-8258 for a quote tailored to your home.

What is the best way to find a good plumber?

Start by checking out trusted review sites like Google, Angi or Facebook to see what locals near Manchester, NH are saying. Then, ask friends, family, or neighbors if they’ve had a good experience with someone—they might lead you straight to a pro you can trust. Before hiring, make sure the plumber is licensed, insured, and brings solid experience to the job.

Where are my emergency shut-off valves?

Every home is a little different, but your main water shut-off valve is typically located in the basement or utility room, right where the main water line enters your house (often near the water meter). We highly recommend locating this valve before an emergency happens and tagging it with a bright piece of tape. If you aren't sure where yours is, just ask your GSMS Service Specialist during your next service visit—we are always happy to show you! (Pro Tip: If you are a GSMS Home Club member, we actually locate and tag your emergency shut-off valves for you during your annual visit, so you should already be good to go!)

What plumbing services does GSMS offer?

We handle water heaters (tank and tankless), kitchen plumbing (faucets, sinks, garbage disposals, dishwashers, and water lines), bathroom plumbing (toilets, showers and tubs, sinks, vanities, and pipe repair), and whole-home water quality and filtration.

Do you install both tank and tankless water heaters?

Yes. Our plumbers install and service traditional tank water heaters and high-efficiency tankless units, including Rinnai tankless systems sized for New Hampshire homes. Learn more on our tankless water heater page.

Can you fix a clogged sink or garbage disposal?

Yes. We repair and install kitchen sinks and garbage disposals and clear common kitchen drain clogs. For a product our plumbers trust between service visits, see our kitchen drain cleaner guide.

What should I do in a plumbing emergency?

First, shut off the nearest water supply valve, or the main shut-off if the leak is large, then call GSMS at 603-424-8258 so we can get a plumber to you as quickly as possible.

Do you offer financing?

Yes. Ask about 0% financing options and current rebates to make larger plumbing and comfort projects more affordable. See financing.

Why Choose GSMS Plumbers?

Comprehensive Plumbing Solutions: We offer a wide range of plumbing services, from water heater repair and kitchen plumbing to bathroom plumbing and pipe replacement. Whether it’s a minor repair or a major installation, we have the expertise to handle all your plumbing needs with precision and care.
Transparent Pricing and Honest Recommendations: We believe in transparency and honesty. GSMS provides clear, upfront pricing for all our services, with no hidden fees. Our plumbers will thoroughly explain the necessary work and offer honest recommendations that are in your best interest.
Prompt and Reliable Service: We understand that plumbing issues can be disruptive and inconvenient. That’s why we offer prompt and reliable service to address your plumbing needs quickly and efficiently. Our goal is to minimize disruption to your daily routine and restore your plumbing system to optimal function.
High-Quality Materials and Workmanship: At GSMS, we use only the highest quality materials and the latest techniques to ensure long-lasting and efficient plumbing solutions. Our commitment to quality means you can trust that our repairs and installations will stand the test of time.
Family-owned and customer-focused: Family-owned since 1987, GSMS treats your home with care and respect. We are a Lennox Premier Dealer and a Rinnai dealer, BBB accredited with an A+ rating and awarded the 2026 BBB Torch Award for Ethics, and proud to give back through our We Love Local program.

Upfront plumbing pricing

No surprises, ever. GSMS provides clear, upfront pricing before any work begins, so you know exactly what to expect. Explore typical costs for common plumbing jobs on our plumbing pricing page, then reach out for a quote tailored to your home. Ask about 0% financing and current specials to make bigger projects easier on the budget.

Get the Best Local Plumbers You Can Trust for 5 Star Service

Don’t let plumbing issues disrupt your home’s comfort and functionality. Trust the plumbing experts at GSMS to provide reliable, efficient, and high-quality plumbing r plumbing system operates smoothly and effservices tailored to your needs. From repairs and installations to maintenance and upgrades, we’re here for you.

Time to call a plumber? GSMS is here to help! Contact us today at 603-424-8258 for plumbing service in and around Manchester, NH or get in touch online with any questions.