A large portion of the savings that is expected when upgrading to a high efficiency condensing furnace is gained due to the reduced electrical consumption with the use of ECM (electrically commutated motor) motors.
In parts of Canada such as Saskatchewan or Alberta where electricity is at a premium, total energy savings can be much more than places such as Winnipeg or Montreal where our rates are much lower.
ECM motors are also promoted as needing little maintenance due to the use of ball bearings and having the ability to operate at various speeds. As a motor that communicates with the heating or cooling components to deliver the optimum amount of airflow (speed) at any given time, increased comfort levels are almost always the primary benefit.
Since an ECM motor does require less maintenance than a typical PSC motor, some homeowners may assume that the other components in their High Efficient Furnace also can continue to operate safely with less preventative maintenance. This could not be further from the truth.
Here are 7 things that you may not know:
- A dirty furnace filter in a high efficient furnace will cause more damage and do so much quicker than in an older style natural draft or mid efficient furnace.
- ECM motors are not available as a universal replacement. A temporary conversion to a standard PSC motor is possible but is never accepted as warranty with any manufacturer.
- ECM motors are made up of 2 main components. The actual motor drive which may be easier to source; and the control module which is unit specific.
- ECM motors are easily and frequently misdiagnosed. When a motor drive is replaced when the control module is faulty, the second motor drive will eventually fail as well. Specific testing equipment along with a factory trained technician is required for complete diagnosis.
- Most local suppliers do not consistently carry enough ECM replacement motors and will have to freight in as needed.
- Each motor component can cost as much as $350.00 – $450.00 each without labor costs.
- Most manufacturers offer a standard 5 yr factory parts warranty. A 6 year old furnace with a failed ECM Motor can easily cost you over $1,000.00 to repair. Annual maintenance and a 10 year Parts and Labor extended factory warranty are more important than ever before.
I work with Tradesman Mechanical and this is my personal opinion. ECM
Mark J Boissoneault