NEW RIVER VALLEY
Christiansburg 540-381-1166
Blacksburg 540-951-5299

SMITH MOUNTAIN LAKE
Southlake 540-576-1200
Franklin County 540-721-5093
Bedford County 540-296-1180

CUNDIFF HEATING & AIR CONDITIONING

ROANOKE VALLEY RESIDENTIAL INSTALLATION
Toll Free  800-660-8398
Main Offices  540-366-0648

CUNDIFFSERVICE COMPANY
COMMERCIAL  DIVISION
Metal Fabrication 540-343-9490
Gas Piping 540-982-1199

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 24-Hour Emergency Service
540-366-0648
SERVICE DEPT.   540-362-8784

                                     SOUTHSIDE
                 Forest 434-846-1323
           Lynchburg 434-846-1323

We employ a team of professional Call Center Specialists and Highly Trained Technicians who are ready and capable of tackling the most complicated problems.

Our 24-Hour Hot-Line is always prepared to dispatch a qualified technician, at your request for Emergency Service, even in the middle of the night, even on holidays.

Each member of our Service Team understands the urgency of your call. We know that you have loved ones whom you wish to make comfortable in your home. We know that you may have health issues as well. That is why seeing that your system is working properly as quickly as possible is our top priority.

Year-round Emergency Service 24-Hours per day,
7-Days a week, when you need it most.

WHY IS PREVENTIVE MAINTENANCE NECESSARY?
 
Preventive Maintenance is essential to the proper functioning of HVAC equipment. If preventive maintenance is not performed regularly or if it is done haphazardly, the equipment will require extensive and costly repairs at a later date.
Preventive maintenance of HVAC equipment requires regular inspections each year. During these inspections, proper operation of the equipment is checked and verified.  All mechanical equipment is designed to operate within certain limits. HVAC equipment is no exception, and if not properly maintained, the equipment will exceed its design limitations with the result being equipment failure.
 
Why must we clean condenser coils?
 
Your heating and cooling equipment is designed to operate between certain outdoor temperature limits. Cooling and condensing of the refrigerant vapor is designed to occur with a particular volume of air flowing through the condenser at a maximum outdoor ambient temperature. (Usually 115°F) If the finned surfaces of the outdoor coils are fouled with dirt, the ability of these coils to transfer heat is reduced and the airflow through the condenser coil is reduced. When the ability to transfer heat is reduced, the operating temperatures and pressures of the unit increase. A unit, designed to operate at ambient temperatures of 115°F or more, may stop operating at an outdoor temperature of 90°F. Due to the reduced heat transfer capability, the operating temperatures and pressures within the unit exceed the manufacturer's safe limit and the unit shuts down. If the unit does not exceed the manufacturer's limits by enough to shut down, it will continue to run at reduced capacity and efficiency, and at an increased rate of wear due to the increased work load.
 
Why Inspect Relays and Contactors?

Electrical relays are designed to open and close a certain number of times with a particular current load, before the contact points are damaged and relay requires replacement. If more than the design-specified current is passed through this relay due to a motor working too hard, or low voltage conditions, the contact points overheat and become damaged. If the electrical contacts in a contactor (large relay) begin to get pitted, and the contactor is not replaced, eventually the compressor motor or the fan motor controlled by the contactor will burn up and require replacement. Once again, if we exceed the design limitations of the device, or its anticipated life span, additional damage is caused.
 
Why Must We Lubricate Bearings and Rotating Components?
 
Bearings and other rotating parts are designed to have a useful life span of hundreds of thousands of hours, provided they are lubricated at appropriate intervals and are not overloaded due to vibration from defective drive belts or dirty blower wheels. If bearings are not lubricated regularly, they will overheat and seize. When this occurs, the bearings fall apart, and the blower wheel, shaft, and housing are destroyed. This is a prime example of a situation where inexpensive maintenance was neglected with catastrophic results.
 
Why Must We Check the Refrigerant Charge on a Regular Basis?
 
A unit operating with an insufficient refrigerant charge can ruin its compressor via two scenarios. The unit icing up due to a low-pressure condition causes the first type of failure, causing the compressor to fail due to liquid slugging. The second type of failure is due to the fact that the compressor requires a certain quantity of cool refrigerant vapor to cool its motor windings. If the refrigerant charge is not sufficient, the motor within the compressor will overheat and burn up.

Why must we replace air filters?
 
Air conditioning equipment is designed to operate with a specific quantity of air passing over its indoor coil surface. When air filters are not replaced, they clog and become coated with dirt. Similarly, the indoor coils get coated with dirt. This dirt reduces the amount of air through the unit below the design limit, leading to catastrophic failure.
 
In the cooling mode, if there is not enough air over the indoor coil, the coil temperature drops. When it drops below the freezing point, ice forms on the coil, which further reduces the airflow, which further reduces the coil temperature. The compressor within the unit is a pump, which is designed to pump a vapor. As the airflow through the indoor coil drops, there isn't enough heat being removed from the air passing over the coil to vaporize the liquid refrigerant inside the coil. Thus, instead of receiving a vapor, the compressor receives liquid refrigerant. This is called "liquid slugging". The effect of "liquid slugging" is similar to the effect of pouring liquid into the cylinders of a gas engine. As liquids are not compressible, cylinder pressure exceeds the design limits,  of the cylinder, and the valves, connecting rods, pistons, or other internal components are destroyed. The units start out requiring that its filters be replaced. Now it needs a new compressor.
 
In the heating mode, low airflow causes the heat exchanger to overheat.  Heat exchangers are designed to operate at temperature between 120°F and 200°F.  At higher temperatures, the heat exchanger oxidizes, its life-span is reduced, or it cracks and breaks. In either case, It makes far more sense to replace air filters regularly than to replace a heat exchanger costing far more.
 
These scenarios all cause damage to occur slowly, over a period of time, usually without being noticed by the occupants of the conditioned space until catastrophic failure has occurred.
 
Regularly scheduled preventive maintenance properly performed, in addition to lowering overall annual HVAC service costs, and reducing the number of emergency calls due to catastrophic failures, will also result in lower utility costs.
 

 

We Service a variety of Heating and Cooling Equipment and All Brands of Equipment Including:

Preventive Maintenance Agreements
To help extend equipment life, lower energy bills, and prevent those surprise repairs, we offer Preventive Maintenance Agreements. With this economical prearrangement, we schedule a routine service call twice a year; ideally just as you are changing from heating to cooling and then again from cooling to heating your home. In this visit we shall perform a variety of maintenance procedures that include:

  • Cleaning Coils
  • Inspection of Relays and Contactors
  • Lubricating various components
  • Checking Refrigerant Charge
  • Changing System Filters
  • Replacing fouled Humidifier Filters
  • Checking UV Bulbs if applicable
  • Checking Air Purifiers and Electronic Air Cleaners

TO PURCHASE A MAINTENANCE AGREEMENT
CALL OUR
SERVICE DEPARTMENT

540-362-8784 OR
OUR MAIN OFFICE
 
540-366-0648

Out-of-area residents may call 
TOLL FREE 1-800-660-8398

 
  • Heat Pumps
  • Furnaces - Gas and Oil
  • Air Conditioners
  • Boilers
  • Radiant Floor Heating
  • Geothermal Systems
  • Indoor Air Quality Products 
  • We provide Service to the following communities:
      Zip Code     Community
    24579   Natural Bridge Station
    24578   Natural Bridge
    24555   Glasgow
    24483   Vesuvius
    24473   Rockbridge Baths
    24472   Raphine
    24439   Goshen
    24435   Fairfield
    24415   Brownsburg
    24010   Roanoke
    24011   Roanoke
    24013   Roanoke
    24012   Roanoke
    24014   Roanoke
    24016   Roanoke
    24025   Roanoke
    24017   Roanoke
    24026   Roanoke
    24024   Roanoke
    24027   Roanoke
    24022   Roanoke
    24028   Roanoke
    24008   Roanoke
    24037   Roanoke
    24009   Roanoke
    24038   Roanoke
    24032   Roanoke
    24040   Roanoke
    24034   Roanoke
    24042   Roanoke
    24036   Roanoke
    24043   Roanoke
    24033   Roanoke
    24044   Roanoke
    24031   Roanoke
    24045   Roanoke
    24035   Roanoke
    24048   Roanoke
    24007   Roanoke
    24006   Roanoke
    24005   Roanoke
    24004   Roanoke
    24003   Roanoke
    24002   Roanoke
    24001   Roanoke
    24029   Roanoke
    24030   Roanoke
    24015   Roanoke
    24070   Catawba
    24020   Roanoke
    24059   Bent Mountain
    24179   Vinton
    24018   Roanoke
    24087   Elliston
    24141   Radford
    24142   Radford
    24143   Radford
    24084   Dublin
    24126   Newbern
    24132   Parrott
    24058   Belspring
    24129   New River
    24301   Pulaski
    24324   Draper
    24347   Hiwassee
    24557   Gretna
    24594   Sutherlin
    24530   Callands
    24531   Chatham
    24069   Cascade
    24139   Pittsville
    24549   Dry Fork
    24527   Blairs
    24161   Sandy Level
    24138   Pilot
    24149   Riner
    24162   Shawsville
    24023   Roanoke
    24061   Blacksburg
    24063   Blacksburg
    24062   Blacksburg
    24111   McCoy Coy
    24060   Blacksburg
    24073   Christiansburg
    24068   Christiansburg
    24504   Lynchburg
    24501   Lynchburg
    24505   Lynchburg
    24503   Lynchburg
    24515   Lynchburg
    24502   Lynchburg
    24506   Lynchburg
    24514   Lynchburg
    24450   Lexington
    24134   Pearisburg
    24136   Pembroke
    24128   Newport
    24124   Narrows
    24086   Eggleston
    24147   Rich Creek
    24150   Ripplemead
    24094   Goldbond
    24093   Glen Lyn
    24167   Staffordsville
    24067   Callaway
    24102   Henry
    24146   Redwood
    24176   Union Hall
    24088   Ferrum
    24151   Rocky Mount
    24184   Wirtz
    24137   Penhook
    24092   Glade Hill
    24065   Boones Mill
    24091   Floyd
    24380   Willis
    24072   Check
    24079   Copper Hill
    24105   Indian Valley
    24131

      Paint Bank

    24127   New Castle
    24426   Covington
    24517   Altavista
    24554   Gladys
    24550   Evington
    24538   Concord
    24588   Rustburg
    24528   Brookneal
    24569   Long Island
    24576   Naruna
    24571   Lynch Station
    24512   Lynchburg
    24513   Lynchburg
    24416   Buena Vista
    24019   Roanoke
    24130   Oriskany
    24050   Roanoke
    24438   Glen Wilton
    24085   Eagle Rock
    24064   Blue Ridge
    24175   Troutville
    24090   Fincastle
    24083   Daleville
    24077   Cloverdale
    24066   Buchanan
    24523   Bedford
    24536   Coleman Falls
    24122   Montvale
    24101   Hardy
    24104   Huddleston
    24121   Moneta
    24095   Goodview
    24556   Goode
    24526   Big Island
    24174   Thaxton
    24551   Forest
    24570   Lowry
    24178   Villamont
    24593   Spout Spring
    24522   Appomattox
    23939   Evergreen
    23958   Pamplin
    24595   Sweet Briar
    24533   Clifford
    24521   Amherst
    24574   Monroe
    24572   Madison Heights 
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