All About Your Heating System

The heating system in your home is probably the most important piece of equipment you have and commonly the most neglected. Many people are unaware of the kind of system they have and how it works, as well as what kind of regular maintenance is required.

Depending on the design, location and restrictions of your home, you might have electric heating, a furnace or a boiler, which could run on natural gas, propane, oil, and depending on the age, even wood. Some homes may have a combination of furnace, boilers, and even heat pumps. Newer homes will also have additional systems installed such as HRV (Heat recovery ventilators). As you can see some homes have a fairly straightforward heating system and some may have a very complex heating system.

Many homes also come with gas fireplaces that provide additional heat, or even localized heat. At times fireplaces can also act as a backup source of heat, so it is important to have regular maintenance on these units as well. Some fireplaces can now also be more decorative than others, but it doesn’t take away from the fact that it is still a gas appliance.

Why do you need maintenance?

No matter what kind of system you may have in your home, you should know the basics of how it functions and most importantly how it is to be maintained.

The importance of regular maintenance comes down to two main factors, safety and efficiency. Although more emphasis is put on efficiency, safety should actually be number one. The purpose of your heating system is to heat your home quickly and comfortably, while running efficiently and safely. The newer the systems the more safety devices, controls, and design improvements it will have that make it more energy efficient. The older your system the less safety features it has to let you know when things aren’t running well or if your facing any hazards. In addition to your heating system, safety devices such as carbon monoxide detectors are highly recommended and should be checked on a monthly basis for proper operation.

What are the different types of heating systems?

Most homes in the Delta, Surrey, White Rock Area, as well as the rest of the lower mainland are heated using Natural Gas or Liquid Propane as a fuel source for their boilers or furnaces. For this reason, we will focus mainly on those two types of fuel. It is important to note that a licensed electrician should maintain electrical furnaces, electrical fireplaces, and electrical baseboards.

Let’s get into the different types of home heating systems.

Forced Air Furnace:

A forced air furnace heats up the home by circulating the air inside the home. As the air circulates through the homes ducting system and furnace it passes through the furnaces heat exchanger where the heat is transferred to the air. The thermostat controls the furnace, which is normally an open switch that closes its contacts when the temperature drops low enough to turn on the furnace. Once the desired temperature is achieved it will open it again, separating the contacts and shutting down the furnace. Furnaces come in different sizes (measured in BTU’s) to correspond with the size of the house and the amount of heat that escapes, which is known as heat loss. The size of the furnace also determines the size of the heat exchanger, blower motor, gas pressure, and flue venting. It is mandatory that a heat loss calculation be done to determine the size of the furnace for every home.

Every furnace that is installed now will be a high efficiency furnace but if you have an older furnace, it is likely a mid efficiency furnace or even a low efficiency furnace.

How can you tell what kind of efficiency your furnace has?

Here are a few things that will help you determine what type of furnace you have.

  1. Low-Efficiency Furnace
    1. Natural draft exhaust for combustion gases
    2. Continuous Standing Pilot
    3. One speed blower and motor, belt driven
    4. Heat exchanger is usually made of cast iron or a heavy steel
    5. AFUE ranges from 56% – 70%
    6. Large in size, mainly due to their inefficiently
    7. Basic controls
      1. Thermocouple
        1. Acts as a safety device to detect flame
      2. Combination high limit and fan switch
        1. Turns fan on and off
        2. Shuts off gas valve on high temperature
        3. Mechanically controlled
  • Single stage gas valve
  1. No control board
  2. Few safety features
  1. Mid-Efficiency Furnace
    1. Equipped with inducer blower (exhaust fan)
    2. Electronic Ignition
      1. Intermittent Pilot
      2. Spark Ignition
  • Hot Surface Ignition
    1. Silicone Carbide Ignition
  1. Multi-Speed Blower Motor
    1. Later models equipped with ECM motors
  2. Steel or stainless steel heat exchanger
  3. Single and Two stage models available
  4. AFUE ranges from 80% to 83%
  5. Compact size
  6. Advanced controls
    1. Single Stage and Two Stage Thermostat
    2. Control board
      1. Controls sequence of operation
      2. Controls 24v and 120v circuits
      3. Provides troubleshooting feedback
      4. Allows for modification of timers and fan speeds
  • Advanced Safety Features
    1. Flame sensors
    2. Blocked vent switches
    3. Flame roll out switches
    4. High limit switches
    5. Pressure switches
    6. Door switches
  1. High-Efficiency Furnace
    1. Condensing flue gases
    2. Inducer blower and condensate pan
    3. Corrosion resistant parts, mostly plastic, as condensate can be very corrosive
    4. Condensate drain
    5. Two pipe direct venting – Plastic piping
    6. Electronic Ignition
      1. Silicone Nitrite Hot surface ignition
    7. Multi-Speed motor
      1. ECM motor
      2. DC motor
  • Fan Motor Controller
  1. Stainless steel heat exchanger
    1. Primary and Secondary heat exchangers
  2. Single Stage, Two Stage, and Modulating Models Available
  3. AFUE ranges from 90% to 98%
  4. Compact Size
  5. Advanced Controls
    1. Single, Two Stage, and Modulating Thermostats
      1. Communicating Thermostats
        1. Displays furnace operating details
        2. Troubleshooting feedback
        3. Advanced controls
      2. Control board
        1. Controls sequence of operation
        2. Controls 24v and 120v circuits
        3. Provides troubleshooting feedback
        4. Advanced Modification
          1. Fan Speeds
          2. Timers
          3. Thermostat Settings
          4. Pre-set Profiles
        5. Operation Feedback
          1. Fan CFM
          2. Furnace Stage
  • Remote diagnosis and controls
    1. Wi-Fi compatibility
    2. Smart phone apps
    3. Network Connection compatibility
  1. Advanced Safety Features
    1. Flame sensors
    2. Blocked vent switches
    3. Flame roll out switches
    4. High limit switches
    5. Pressure switches
    6. Door Switches
    7. Outdoor Sensors

Whether it’s a low, mid, or high efficiency furnace the maintenance protocols may be similar.

  1. Gas Pressures
    1. Every furnace has a design pressure that it operates at, this is called the manifold pressure
    2. The manifold pressure needs to be set to the manufacturers specification, older units usually are set to 3.5” water column, but mid and high units have different ranges.
    3. Inlet pressure needs to check to make sure that the unit is getting enough gas and the pressure is consistent.
  2. Temperature rise
    1. The temperature rise is the differential of the air temperature in the supply and return ducts of the system
    2. The manufacturer gives you ranges at which your furnace should be running
    3. Improper temperature rise could result in short cycling as well as uneven heat, which can be uncomfortable.
  3. Safety Features
    1. All furnaces come with safeties
    2. It is very important that all safeties are working as per their design specification and have not been jumped or bypassed.
  4. Sequence of operation
    1. All furnaces follow the same sequence of operation
      1. Call for heat
      2. Safety check (varies depending on furnace)
  • Ignition
  1. Sense for flame
  2. Furnace heats up heat exchanger
  3. Blower runs
  • Heat call is satisfied, Thermostat opens
  • Furnace is on standby
  1. If there are hiccups, delays, or it restarts sequence a few times, it is an indication that there is something wrong with the sequence of operation and needs servicing.
  1. Visual inspection
    1. Visual inspection of the whole furnace and all internal components, duct work, and venting. Looking for signs of corrosion, leaks, tears, and cracks.
    2. Heat registers and return air grills that are clean and free from obstruction
    3. Proper combustion air and fresh air
    4. Clean and proper air filter

A safety inspection to check all these factors and make proper adjustments should be done on an annual basis by a trained Heating Technician with a gas B ticket. Give us a call or send us an email and we would be happy to come over and take a look at your system to make sure that It is running safely and efficiently.

Boilers:

A boiler system heats up the home by radiating heat from either a baseboard heater or a radiant floor loop. A boiler can be very intricate or very simple depending on the needs and how much control you want to have over operating the system. A boiler system has a series of loops, each loop serving an area that requires heating. Normally one loop, called the boiler loop, circulates the water through the boiler. The boiler will also have a few pumps depending on the design, one being the boiler pump that circulates the boiler loop. A boiler can help provide better control of the heating system by creating zones and each zone its own thermostat. A boiler can also be setup to work with a storage tank to provide domestic hot water, and a fan coil to provide forced air heating.

Maintenance on boilers should be completed on an annual basis to ensure that the system is running safely and efficiently. A system that is not well maintained could not only cost you enormous amounts in your gas bill but could also be costly to repair if it has been neglected.

Boiler systems come with a number of safety features that help your system run safely or even shut it down if the system is out of calibration. Some of those safeties include:

Pressure Relief Valve: Every boiler system must have a functional pressure valve; it is designed to maintain safe pressure levels by opening and releasing water from your system when it reaches 30 psi. A leaky valve could be an indication that your boiler or expansion tank could be faulty or undersized.

Low-water cut-off: A low water cut off is designed to cut the electrical power of the boiler system if it senses low water in your system. If this valve has been activated a good place to start is the pressure gauge to see what the pressure is and then look for a reason as to why the water level has gone down. It could be a leak in the system, the relief valve has gone off, or a faulty cut-off valve.

Flow switch: A flow switch helps prove that there is water flowing in the system, same as the low-water cut-off, the flow switch will cut out the electrical power if it does not sense water flow. A faulty pump, low water level in the system or a faulty switch might activate a flow switch.

High-limit: A high limit switch will turn the power off to the gas valve if the temperature in the boiler reaches the limit on the switch. A high limit switch can be set from 180-220 degrees Fahrenheit but should not be adjusted unless you have a good understanding of how a hydronic heating system works and is designed.

Expansion Tank: An expansion tank is designed to absorb the thermal expansion of the system when it is running. The tank must be setup properly from the beginning to ensure it is the proper size and that the pressure corresponds with the system pressure. A faulty or improperly setup expansion tank will cause issues with the system pressure resulting on your relief valve letting out water and your feed valve introducing new water, which will cause other issues with your system.

Pressure Reducing Valve: The pressure reducing valve or boiler feed valve fills your system to the design pressure usually between 12-15 psi, if the pressure drops the valve automatically open up to fill the system. A faulty reducing valve could result in feeding the system to a higher pressure than the design pressure or not feeding the system at all.

Other components that serve to make sure the system operates properly are:

Air Vents: The air vents help the air in the system escape; newer vents work automatically while some of the older ones must be opened manually. Making sure that your vents are working properly will help prevent air locks in your system; air locks affect the circulation of your system, limiting the distribution of heat throughout the home.

Mixing Valves: A mixing valve is used to help control the temperature of the water for different loops of the system. For example, a slab will be heated at a lower temperature then a radiator but the boiler will only provide one outlet temperature, it mixes the outlet temperature of the boiler with the return temperature to provide a lower temperature for the loop serving the slab. A faulty mixing valve could result in a slab getting too much heat or too little heat resulting in the heating system heating up too fast or too slow. High temperatures in the slab could result in cracks to your slab.

Pressure Gauge: The pressure gauge will display the pressure in the system, although it doe not have any direct effect to the system, it does help with the diagnosis and check up of the boiler.

Circulator Pumps: The pumps circulate the water in your system. Depending on the design of your system you could have a pump which will circulates the water in the boiler loop and one pump that circulates the water for all your zones. You could also have a pump for each zone in the home.

Zone Valves: The zone valves help control the heat to each zone or set of zones in your home. The zone valves can be wired to a control panel or directly to boiler board. On smaller systems the zone valve can be used to turn the pumps on and off with the call for heat.

A boiler system can become very dangerous if neglected or not set up properly, to make sure that your system is working safely, you can have one of our trained heating technicians complete a safety inspection of your entire system. Adjustments are included with the inspection.

We are experts of our craft and will ensure the safety and efficiency of your homes heating system, we would love to meet with you and help you take great care of your home.

Contact us today for an inspection!