FURNACE USER MAINTENANCE
Before proceeding, be sure the area is well ventilated. Turn the thermostat OFF. If the blower is running, wait until it stops automatically. Turn OFF the gas and electrical power supplies to the furnace. Check all metal parts and surfaces to be sure they have cooled to room temperature before you begin.
Blower Care
Even with good filters properly in place, blower wheels and motors will become dust laden after long months of operation. The entire blower assembly should be inspected annually. If the motor and wheel are heavily coated with dust, they can be brushed and cleaned with a vac- uum cleaner. If the blower cannot be properly cleaned without removing it from the furnace, then this service must be performed by a qualified service agency.
The blower can be serviced/removed through the blower access panel on the inside of the furnace. If there is a combustion air pipe installed inside the furnace, it may have to be removed to access the blower access panel. After the combustion air pipe is removed, it is easy to remove the inside blower access panel by pushing it up, against a spring, or removing the screws of the access panel. Blower is now ready to be serviced through the opening.
If the blower has to be removed through the inside blower access panel, then the top flange, blower door switch and bottom flange will also have to be removed on some models, On some other models, top and bot- tom angles will have to be removed to slide the blower out of the fur- nace.
Make sure you DO NOT move the clip-on weight on the indoor fan wheel when cleaning the wheel. This weight is used to balance the wheel. Moving the weight will cause the fan wheel to vibrate.
Air Filters
The filters should be checked every 3 months. On new construction, check the filters every week for the first four weeks and every three weeks after that, especially if the indoor fan is running continuously. When replacing the filter(s), refer to Table 1 to be sure you install the right size filter for your furnace. Dirty filters greatly restrict the flow of air and may cause damage to the moving parts of the furnace. If the filters become clogged the heat exchangers and blower motor could overheat resulting in a potentially dangerous situation.
Never operate your furnace without a suitable air filter.
Removing Filters
Most downflow furnaces have their filters located on the top of the fur- nace in an external filter rack. To check filters you should:
1.Follow the instructions to turn off the appliance before servicing.
2.Filters are installed in the return air plenum above the blower assembly. An “A” frame assembly supports the filters. Lift the filter slightly and remove for service.
3.Follow the instructions “HOW TO CLEAN YOUR FURNACE’S FIL- TER”.
4.Reverse the procedure to reinstall filters.
5.Follow the operating instructions to place appliance in operation.
FILTER RACK
RACK AND FILTERS SECURED
INSIDE BLOWER SECTION
FOR SHIPMENT
CASING SIZE | DIMENSION FH |
14-1/2” | 13-1/4” |
17-1/2” | 12-1/2” |
21” | 11-1/2” |
24-1/2” | 9-3/4” |
NOTE: FILTER ACCESS THROUGH
DUCKWORK MUST BE PROVIDED
FOR REMOVAL AND CLEANING
| | FILTERS |
| DUCKWORK | FILTER |
| RACK |
| |
| | FH |
FIGURE 7: Filter Rack Assembly and Attachment
TABLE 1: Filter Sizes
Input | CFM | Cabinet | Top Return |
BTU/H (kW) | (m3/min) | Size | Filter in(cm) |
60 (17.6) | 1200 (34) | B | (2) 14 x 20 (36 x 51) |
80 (23.4) | 1200 (34) | B | (2) 14 x 20 (36 x 51) |
80 (23.4) | 1600 (45) | C | (2) 14 x 20 (36 x 51) |
100 (29.3) | 1600 (45) | C | (2) 14 x 20 (36 x 51) |
100 (29.3) | 2000 (57) | C | (2) 14 x 20 (36 x 51) |
120 (35.1) | 2000 (57) | D | (2) 14 x 20 (36 x 51) |
Externally Mounted Air Filters
Some installations may have the air filter in a rack attached to the cas- ing of the furnace or placed in the return air duct. You can gain access to the filter by pulling on the door or unscrewing the retaining screw, then slide the filter(s) out of its channel. Replace throw away filter(s) with the same size new filter(s). Throw away filter(s) may be replaced with cleanable filter(s) at this time. Cleanable filter(s) may be cleaned as described in the manufacturer instructions or as described below and then re-installed.
How to Clean your Filter
High-velocity filters may be cleaned with a vacuum cleaner or washed with a garden hose. Be sure to shake off excess water and allow filter to completely dry before re-installing the filter.
To replace the filter after cleaning you must do the following:
1.Slide filter into place.
2.Snap the door on or place the door in position.
3.Make sure the door is secure to the end of the filter rack.
4.For filter grilles, place the filter into the grilles, close the grille cover and tighten the retaining screw.
Every time the filters are changed the following items should be visually inspected:
•Check combustion air and vent pipe for blockage or leakage.
•Check all components to be sure they are in good condition and that there are no obvious signs of deterioration.
•Check the drain lines to make sure there are no cracks or leaks.
•Check for dirt or lint on any surfaces or on components. Do not try to clean any of the surfaces or components. Cleaning of the fur- nace and its components must be done by a qualified service pro- fessional.
