Use Serial Number to Tell the Age of a Furnace in San Diego

If you live in San Diego, there are a number of benefits in knowing how to use your heating system’s serial number. First, it tells you in what year the furnace was manufactured, so you can supply that information when you need furnace repair or maintenance. Knowing your system’s age is important because it can tell you a lot about whether you might be able to get by with furnace repairs; or be forced to completely replace the heating system with a new one.

The most popular furnaces that have many years in the field include Carrier, Bryant, Lennox, Rheem and Goodman/Amana. Each of these brands have their own methods of identifying system age from serial numbers.

Most furnaces have a useful and “safe” life between 15 and 20 years. Knowing your furnace system’s age is also important when it comes to the issue of connecting it to an air conditioning system. Most people don’t know that if you want to add air conditioning to your home, your furnace has to be compatible with the new air conditioning system. There are two components to an air conditioning system: the cooling coil or “indoor” component, and the big gray or green outdoor unit, called a condenser.  If you have an older furnace, it most likely won’t be compatible with the newer coil, and subsequently, the newer outdoor air conditioning condenser.  Today’s air conditioning systems provide super high energy efficiency  – but they won’t deliver these kinds of energy savings when paired with furnaces that use older and outdated technologies.

Finding the serial number on your furnace may differ from these general guidelines, but be patient – it might take a little foraging to find it. Try these tips first:

Remove the metal door on the exterior of your furnace.  You’ll usually find this along the bottom part attached to  the front of the unit. Inspect the interior of the metal door – you might see a a label or tag with the furnace’s serial number. If you’re lucky, it could also show the actual date of manufacturer.

If you can’t find the serial number or date of manufacture, switch off the furnace’s power and view the fan and its blades. If you have an older furnace, they sometimes had serial numbers stamped into the metal of the fan itself.

Where to find a Lennox Serial Number on your Furnace in San Diego

The model and serial numbers for Lennox Furnaces can be found by unfastening the top-front service panel.  Look down the left side of the interior furnace housing, or on the top of the blower deck. The efficiency rating – whether your system is an 80% or 90% AFUE, plus whether the furnace is a horizontal or vertical unit, will also determine where you will find the serial number.

Lennox furnace efficiency affects serial number placement







Where to locate a serial number on a Rheem Furnace or Air Conditioner

On Rheem furnace and air conditioning systems, there’s always a letter in the middle of the serial number.  Look at the first two digits after the letter. The first two numbers are the week that it was manufactured. The next two numbers – the  third and fourth numbers after the letter – are the year the system was manufactured. You can also cross check the serial number info with a month and year shown here the upper right part of the data plate. Therefore, “G0994” in the serial number pictured here, means the unit was manufactured during the 9th week of 1994.

How to find a rheem serial number on your furnace or AC





How to Determine System Age on Carrier, Bryant and Goodman/Amana furnaces

Other furnaces made by Carrier, Bryant, Goodman and Amana have their own methods of determining system age. Here are some useful links to their sites where you can find info on system age for many different manufacturing years:

Carrier –

Bryant –

Goodman –





Not Just for Air Conditioning: 4 Hi-Tech Ways Mini-Splits Keep You Warm, Too 

Ask the average San Diego homeowner or business owner about ductless mini splits, and most
will tell you they believe mini splits are for air conditioning only. We’re here to correct this
common misconception by summarizing some of the features and benefits of mini split
technology as it relates to providing energy efficient heating in particular!

Heat Pump Technology Makes For All-In-One Solution

Mitsubishi mini split systems employ heat pump technology, which allow the same compressor
to provide heat and air conditioning. Because one compressor provides both heating and air
conditioning, you won’t need a separate furnace to couple with your air conditioning system.

Consistent Performance With Hyper Heating Technology

Our complete line of Mitsubishi ductless mini splits feature an innovative and exclusive
technology called “​Hyper Heating​.” ​An enhanced compressor system reliably keeps you
comfortable, even at super-frosty outside temperatures down to sub-zero levels of -13° F. Since San Diego’s perfect climate rarely approaches freezing, you’ll never have a problem heating even your coldest rooms quickly and efficiently.

Immediate Warmth With Hot-Start Technology

An integral component in all Mitsubishi mini split models, Hot-Start Technology quickly delivers
warmth when turned on. This reduces drafts and enables you to enjoy the heated
air right away.

Intelligent 3D i-see Sensor™

Some models of the Mitsubishi mini split line use advanced features like the ​3D i-see Sensor™​ to monitor the number of people in rooms and adjust the temperature automatically. These units can even sense when a room is empty and automatically switch to energy saving mode without being controlled by a user.


So don’t just consider ductless mini splits for air conditioning! They provide the same, on
demand, energy efficient heat wherever you need it most – without having to heat every room
at once like traditional heating and air conditioning systems.

new air conditioner financing

New 100% Financing with No Upfront Payments, No Payments Until December 2018!

Carini Heating, Air and Plumbing is very excited to offer an all-new financing program, available for purchases of all Carini products. The new financing program allows customers to purchase the industry’s most energy efficient heating and air conditioning products with the following key benefits:

1. No upfront payments
2. Eligibility based on property equity – not credit reports
3. 100% financing
4. No payments until December 2018
5. Allows purchase of heating and air products now, avoiding manufacturer price increases
6. Payments are incorporated into and repaid over time through property taxes with terms of up to 30 years, depending on service area and type of improvement

Our new financing program is offered through our partner, Ygrene. Ygrene Energy Fund is a national leader in residential and commercial clean energy financing. Founded in 2010, Ygrene’s award-winning, privately funded Property Assessed Clean Energy (PACE) program is revolutionizing the home improvement industry, making it easier for property owners to invest in their futures and a healthier environment.

For more information about how to use our new PACE Financing, please contact our Design Specialists at 619-843-0997 – or view our video about financing a new heating or air conditioning system.

Lennox Furnace and Heating Repair in San Diego

Carini Heating, Air and Plumbing is San Diego’s premier HVAC contractor, offering repairs and maintenance services on all Lennox heating and air conditioning products. San Diego home and business owners choose Carini for all types of furnace repairs, from cracked heat exchangers to ignition control and faulty thermostats. Furnace and heating system repairs on Lennox, Carrier, Bryant, Rheem and Goodman/Amana systems often fall into the following categories:

1. Problems with faulty thermostats – make sure to check all thermostat batteries before calling for service. Other “stat” issues could be related to faulty wiring or dirt accumulation. Problems might also be solved by replacing a fuse or circuit breaker.

2. Problems with air circulation –  from fan motors, limit switches, belts and bearings:

  1. Loud high pitched sounds upon startup indicate you could have a bad belt.  Belts don’t have to be super expensive but it’s far better to replace them before they break.

3. Dirty or clogged filters that inhibit healthy airflow and can cause other major system problems

4. Problems with the pilot light or ignition controls, causing inconsistent or no heat at all

5. Lack of recommended maintenance can result in system failure, wasted energy and increased utility costs.

Determine Lennox Furnace Age Through the Serial Number

If you can determine the age of your Lennox furnace and heating system, you can save some time in getting it diagnosed properly and figuring out what may or may not be covered under your original Lennox warranty.

Click here to get this handy guide on how to determine system age

For quick and responsive service on your Lennox or other brand furnace, call us at 619-843-0997; or fill out the form on our website at:


The 3 Most Common Ductless Mini Split Applications

Ductless mini split technology is growing by leaps and bounds, along with the types of applications that we are finding most popular out in the field. When this energy saving technology first became popular, it was used mostly in small apartments in Europe, South America and Asia, in one to a maximum of two zones. When you’re traveling in these areas of the world, it’s not uncommon to see mini split outdoor units on balconies or rooftops. In some countries – like Spain for example – you can often see what we call “Mini Split Blight,” where outdoor condensers are affixed, like so many pieces of a puzzle, to outside walls of apartment buildings, and the idea of following building codes or HOA rules seem not to be relevant considerations. Thankfully, cities like San Diego and surrounding municipalities require permits for where units can be placed and other safety and aesthetic considerations.

Since the early days of mini split technology, consumer demand has skyrocketed, and the most popular applications have evolved from single and two zone systems to a wide range of uses. Here are the current most popular uses for ductless mini splits:

  1. New Construction. When adding on a granny flat, art studio, “man cave,” craft room, office or extra bedroom to your existing home, mini splits are becoming the preferred method of adding air conditioning and heating. Some consumers attempt to add on to their existing whole-home HVAC system by extending ducting into new rooms. The main problem with this method is that your existing system was likely “sized” to your home based on square footage and other “load calculation” measurements. The AC condenser, furnace and evap coil may be the right size for your home before the add-on, but not sufficient for the new square footage and changes in sun exposure, window/glass technology and other factors that dictate the ideal system configuration.  Adding mini split units for add on construction take the guesswork out of the new square footage equation, because they can be easily sized to the new space without impacting the existing system.  And adding in a new mini split also provides a first step in adding on HVAC equipment for maximum energy efficiency – since you can condition the new space only when you need added cooling or heating.
  2. Areas with No Access to Ductwork. Many installations can’t support adding ductwork to provide heating and cooling to rooms or offices. No attic or crawl space under the house or in an apartment usually means there’s no viable way to run ductwork. The challenge then is where to place the outdoor condenser. Condensers are most commonly placed on rooftops, alongside walkways in yard, and on balconies where HOA rules permit their usage.
  3. Whole home or First Time System Replacements.  Over the last several years, we’ve seen an exponential increase in the use of Ductless Mini Split systems as replacements for traditional whole home ducted systems, or for applications where homeowners are installing air conditioning for the first time in their houses. When you factor in energy savings, much lower operating costs and the flexibility of cooling and heating specific rooms, the economics of choosing mini splits vs. traditional HVAC systems become very compelling.


How to Tell the Age of a Rheem Water Heater

If you’re a San Diego home or business owner with a Rheem water heater, there is a variety of useful information located on the Rheem water heating product label. If you ever need to call us to evaluate a repair or discuss installation of a Rheem water heater, you probably want to start with the age of the system.

Here’s an example of a Rheem water heater ten digit serial number and what each digit means:

Serial Number 12 09 D 01234

In this example,”12″ means the month manufactured – December. “09” indicates the year manufactured – 2009. Rheem’s headquarters are in Atlanta, GA, with manufacturing plants in Fort Smith, Montgomery, AL; Oxnard, CA; and Egan, MN for the United States; a plant in Quebec for Canada; and a plant in Mexico.

Consider that Rheem has three primary water heater models that we sell, install and service in San Diego: Tank, tankless and heat pump/hybrid. On all models, the serial number on all Rheem water heating product rating labels use ten (10) digits, and are located as follows in the images below:

Rheem tank water heater serial number locator san diego

The age of a Rheem tankless water heater is on the product label

Rheem heat pump or “hybrid” water heaters have 10 digit serial number

Rheem tankless water heaters place the serial number in the inside of the heater body on the right side.

Serial number plates for Rheem heat pump water heaters are located on a label on the upper left side of the system.





For more information about Rheem water heater installation, repair or maintenance agreements in San Diego, contact Carini Heating, Air and Plumbing at 619-843-0997;;

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Carini Blog

Why Does My AC Unit Smell Funny?

The main purpose of any AC unit is to regulate air temperature and control airflow, but the salesperson said nothing about air odors. Many homeowners ask us about a weird smell coming from their AC unit from time to time. Simply put, the air from the vent shouldn’t smell weird or smell at all and there are several reasons it does. Some odors are only temporary and pose no harm, while others are more persistent and could mean that something is wrong with your air-conditioning system. The next time you sense something smells foul inside your AC take notes and consult an experienced air conditioning expert whether the smell is a cause for alarm.

Fire to the Smoke

If your AC unit suddenly and inexplicably starts producing an odor reminiscent of smoke, it could potentially be a red flag. Smoke is frequently associated with a mechanical or an electrical issue within your AC system. Some parts like the fan or the motor have a tendency to overheat or even catch fire if you don’t subject your AC to regular maintenance.

If the AC unit smells like it had caught fire and smoke flows through your vents, turn off the AC system at the thermostat immediately. Go outside and check the outdoor unit. If there’s smoke coming out of the condenser or you can just smell it, don’t turn the system back on. Call an emergency air conditioning expert immediately.

Tobacco Smoke

If you have a heavy smoker in your home, your AC unit will likely spread that smoke across every room and absorb the odor inside the system. The stale smell of tobacco smoke can get absorbed by the condenser coils and the AC will spread the smell across the ventilation ducts. If you are a smoker this smell might go over your head, but when a non-smoker family buys a home from a smoker they will most certainly smell something is wrong with the AC.

Fortunately, a good company offering air conditioning services in has the tools and the technique to clean the ducts and minimize the odor caused by excessive smoking. However, doing the same with the coils can prove more difficult, which is why it is advised that you schedule regular maintenance if you have a heavy smoker in your home.

Damp Odor

If the air coming from the vents has an unpleasant smell reminiscent of mildew or mold, that is probably exactly what it is. Mold is known to form in the ductwork and on the coils, and if left unchecked can spread across the entire home. There could be several reasons why the inside of your AC system caught mold, and the likely ones are clogged drainage tubes, bad insulation or a leak in the ducts. To get rid of the unpleasant smell an expert must find the cause of the problem first, and then proceed to handle the cleanup.

It is important to handle this issue as soon as possible, as mold can spread across the entire home through the AC system. Mold could cause far more problems that the unpleasant smell, it could cause severe health conditions.

First Winter Run

When you run your furnace for the first time in the winter, a weird smell is not an unusual occurrence. This is one of the examples where the smell is harmless and often resolved quickly on its own. It is caused by the dust accumulated in the heating system during the summer. When you turn the system on again in the winter, the dust burns and produces the peculiar smell. Open a few windows and let your home vent and you’ll be rid of the smell easily.

New Ecobee3 Programmable Thermostat is Ideal for San Diego HVAC Needs and is HERO Program Approved

SAN DIEGO, California, November 19, 2014 – Carini Heating, Air and Plumbing is proud to announce the availability of a great new programmable thermostat from Toronto, Canada – based thermostat manufacturer, Ecobee. The Ecobee3 is similar in look and feel to the popular NEST thermostat, but has some additional distinguishing features that make it ideal for climates like we have in the San Diego area.

The company positions this new device for “Homes That Have More Than One Room,” a kind of tongue and cheek reference to its unique ability to place up to 32 additional remote temperature sensors in different locations throughout a home. These sensors enable the measurement of temperature and occupancy in multiple areas of the home, providing increased comfort when you’re home and energy savings when you’re not. Additionally, homeowners can monitor and control their ecobee3 thermostat from anywhere, with easy-to-use smartphone or tablet apps.

Ecobee3 programmable thermostat

Three Built in Sensors
There are three sensors built into the Ecobee3. One sensor wakes up the display when you get close to the unit. This is called the proximity sensor. Another one, called the occupancy sensor, tells the thermostat is the room is currently occupied. And a third sensor measures temperature in the room in which it is located.

Ecobee stat photo 2

Connectivity Through Most Standard WiFi Routers
The Ecobee3 works with any typical 802.11 b/g/n WiFi router. These include routers from manufacturers including Cisco and Linksys. Here is a link to some popular Ecobee-compatible routers

HERO Program Approved
The HERO financing program is growing in popularity throughout San Diego County for its simple application, tax deductible interest payments and qualification based on home equity versus credit reporting. HERO is designed to encourage homeowners to install high efficiency and energy saving HVAC products, and a programmable thermostat is normally a component of these kinds of systems. At Carini Heating, Air and Plumbing, we recommend the Ecobee3 to customers financing their heating and air conditioning purchases through the HERO Program.

Customer Service Award Nomination Given to Carini

SAN DIEGO – May 30, 2014 – The San Diego Regional Chamber of Commerce has chosen Carini Heating, Air and Plumbing as a finalist for the Excellence in Customer Service Award in the 2014 Small Business category. The award finalists were announced by former San Diego Mayor Jerry Sanders, now President and CEO of the San Diego Regional Chamber of Commerce. The awards will be presented June 17 at an awards banquet at the Omni San Diego Hotel.
San Diego HVAC service award recipient
Two other worthy nominees were also announced in this category: Bekkers Catering and My Lineage, Inc. Read more