York 035-18843-000-a-0402 manual Cleaning Burners, Cleaning Flue Passages Heating Elements

035-18843-000-A-0402

mary air shutters to give a distinct, sharp blue flame as explained under BURNER AIR SHUTTER ADJUST- MENT. If it is not possible to adjust for the proper flame, the burners may need cleaning.

CLEANING BURNERS

Remove them from the furnace as explained in BURNER INSTRUCTIONS section in the Unit Installa- tion Instructions. Clean burners with wire brush and vacuum as needed.

CLEANING FLUE PASSAGES AND

HEATING ELEMENTS

With proper combustion adjustment, the heating ele- ment of a gas fired furnace will seldom need cleaning. If the element should become sooted, it can be cleaned as follows:

1.Remove the burner assembly as outlined in “BURNER INSTRUCTIONS” of the unit installation instructions.

2.Remove the unit roof from over the gas heat section.

3.Remove the top plate and the top draft blower wheel from the upper draft blower housing.

4.Remove the screws holding the top of the flue collec- tor box. Carefully remove the top of the flue collector box without ripping the adjacent insulation. Then remove the center divider plate separating the upper and lower flue boxes.

5.On the inside of the flue collector box, remove the flue baffles from the tube interiors. Note the last bend of the baffle fits tightly against the tube forcing the end of the baffle to lock into the tube collar. This collar is formed when the tube is expanded into the end sheet. To remove, move the end of the baffle toward the center of the tube releasing the end of the baffle from the tube collar, then pull straight out of the tube. Refer to Figure 4.

6.Using a wire brush on a flexible wand, brush out the inside of each heat exchanger from the burner inlet and flue outlet ends.

7.Brush out the inside of the flue collector box and the flue baffles.

8.Run the wire brush down the vent hoods from the flue collector end.

9.If soot build-up is particularly bad, remove the vent motor and clean the wheel and housings. Run the wire brush down the flue extensions at the outlet of the vent housings.

10.After brushing is complete, blow all brushed areas with air or nitrogen. Vacuum as needed.

11.Replace parts in the order they were removed in Steps 1 thru 5.

12.When replacing the center and top of the flue collec- tor box, be careful not to tear the adjoining insula- tion.

13.Ensure that all seams on the vent side of the com- bustion system are air tight. Apply a high tempera- ture (+500°F) sealing compound where needed.

FIGURE 4: TYPICAL FLUE BAFFLE

INSTALLATION

AIR FILTERS

Units up through 125 MBH input (3-6 Ton) are shipped with 1" throwaway type air filters. All other units contain 2" filters. The filter racks on 3-6 ton units will receive 1" or 2" filters. Filters can also be installed in the building at a suitable return air location if an economizer or out- side air accessory is not used. Filters must always be used. They should be inspected once a month and thoroughly cleaned or replaced if it appears they are beginning to accumulate excessive dirt. Filter sizes and quantities are shown in the following table.

			QUANTITY PER UNIT (Nom, Tons)
THROW
		15		20
AWAY
		TON		TON
FILTER
	3 - 6	STD		STD	25 TON STD	15 - 25 TON ULTRA
SIZES
	TON	&		&	EFFICIENCY	HIGH EFFICIENCY
(Inches)
		HIGH		HIGH
		EFF.		EFF.
14 x 20	2	~		~	~	~
14 x 25	1	~		~	~	~
12 x 24	~	~		~	12	12
16x 20	~	~		4	~	~
16 x 25	~	~		4	~	~
18 x 24	~	5		~	~	~

Unitary Products Group 5