•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.
If, during the inspection of your furnace, you find any of the following conditions:
•Excessive amounts of dust and lint on components.
•Damaged or deteriorated components or surfaces.
•Leaks or blockage in the vent pipe passages.
•Water on any surface inside or outside of the furnace.
Do not operate the furnace, call a certified dealer / servicing contractor to check and / or clean your furnace, or for more information if you have questions about the operation of your furnace.
If all components appear to be in good operating condition, replace the front panels. Turn ON the gas and electrical power supplies to the fur- nace, and set thermostat to the desired temperature.
Air Filters
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. 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) you must use filters that are the same size as those recommended in Table 1. Use the following pro- cedure to determine the filter size. Never operate your furnace without a suitable air filter.
1.Measure the furnace width and use that measurement to deter- mine the cabinet width.
•A
•A
•A 21” wide cabinet is a “C” cabinet.
•A
2.Locate the cabinet size on Table 1 then determine whether you have a bottom or side return air duct using the following method.
TABLE 1: Recommended Filter Sizes
a.If the return air filter is on the left or right side of the furnace it is a side return
b.If the air filter is on the bottom of the furnace then you have a bottom return.
C.If the air filters are on the bottom and the side of the furnace then you have a bottom and side return. You must replace both air filters. Table 1 will indicate 2 filters by using brackets with the number two (2).
D.If the air filters are on both sides of the furnace then you have a two sided return. You must replace both air filters. Table 1 will indicate 2 filters by using brackets with the number two
(2).
3.After you determine the cabinet size and what return configuration you have, look up the recommended filter size from Table 1.
Replacing Filters
Filters used with this furnace must be installed external to the furnace casing. DO NOT attempt to install filters inside the furnace cabinet.
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. If the filter location or replacement process is not obvious, contact your installer or service technician for assistance. 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.
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
Input/Output | Nominal CFM | Cabinet | Side Return | Bottom Return | |
BTU/H (kW) | (m3/min) | Size | Filter in. (cm) | Filter in. (cm) | |
40 (11.7) | 1200 (34) | A | 16 x 25 | (41 x 64) | 14 x 25 (36 x 64) |
60 (17.6) | 1200 (34) | B | 16 x 25 | (41 x 64) | 16 x 25 (41 x 64) |
80 (23.4) | 1200 (34) | B | 16 x 25 | (41 x 64) | 16 x 25 (41 x 64) |
80 (23.4) | 2000 (57) | C | 16 x 25 | (41 x 64) | 20 x 25 (51 x 64) |
100 (29.3) | 2000 (57) | C | 16 x 25 | (41 x 64) | 20 x 25 (51 x 64) |
120 (35.1) | 2000 (57) | D | (2) 16 x 25 | (2) (41 x 64) | 22 x 25 (56 x 64) |
135 (39.6) | 2000 (57) | D | (2) 16 x 25 | (2) (41 x 64) | 22 x 25 (56 x 64) |
NOTES:
1.Air velocity through throwaway type filters may not exceed 300 feet per minute (91.4 m/min). All velocities over this require the use of high velocity filters.
2.Air flows above 1800 CFM require either return from two sides or one side plus bottom.
How to Clean your Filter
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 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 and bottom angles will have to be removed to slide the blower out of the furnace.
4 | Unitary Products Group |
