Lennox International Inc. GWB9-050IH-2 User Manual

• The acidic nature of fl ue gasses condensing on 

aluminum boiler sections may cause formation of 

aluminum oxide. This oxide formation is normal, 

is generally uniform throughout boiler sections, 

and represents negligible mass of aluminum that is 

consumed by oxidation during life of the boiler. 

• If left unchecked, this buildup may eventually cause 

blockage of fl ue gas passages in boiler sections, 

reducing effi ciency, and ultimately shutting down the 

boiler due to lack of combustion air fl ow. 

• Regular service and maintenance by a qualifi ed service 

agency must be performed to assure safe trouble free 

operation and maximum effi ciency.

Annual service call by qualifi ed service agency, which 

includes:
A. Examine fl ue passages between boiler sections, 

burner, and condensate lines, and clean if 

necessary following 

 

“Annual Examination And 

Cleaning Of Boiler Components” on page 46

 .

B.  Visually inspect venting and air intake system 

for proper function, deterioration or leakage. If 

vent or air intake show any signs of deterioration 

or leakage, repair or replace them, immediately. 

Insure proper reassembly and resealing of vent and 

air intake system

C.  Check for and remove any obstruction to fl ow of 

combustion air or venting of fl ue gases. Check air 

baffl e located inside 1½” x 2” fl exible coupling on 

mixer, clean if necessary and make sure to put it 

back. Refer to repair parts diagram of mixer and 

pressure switch assembly for exact location.

D.  Follow instructions for

 

“Operating Instructions” on 

page 38

 .

E.  Follow instructions for “Check Out Procedure and 

Adjustment” on page 42 .

F.  Visually inspect condensate drain lines for proper 

operation and deterioration. Check for plugged 

condensate drain lines.

G.  Check silicone rubber seals between boiler sections. 

Insure that there are no leaks. Use RTV silicone 

rubber adhesive sealant rated for at least 400° F to 

replace or repair seals in locations where original 

seals have deteriorated.

H.  Check all gasketed joints for leakage, and tighten 

bolts or replace gaskets if necessary.

I.  Remove jacket front and top panels and check for 

piping leaks around relief valve and other fi ttings. 

Repair, if found. DO NOT use stop leak compounds.

Check boiler area is free from combustible materials, 

gasoline, and other fl ammable vapors and liquids.

Circulator pump and blower motor furnished with boiler 

are permanently lubricated from factory and require no 

further lubrication. Additional or non-factory supplied 

pumps and/or motors should be lubricated according to 

the pump and/or motor manufacturer’s instruction. 

Check for and remove any obstruction to the fl ow of 

combustion air or venting of fl ue gases.

Check boiler area is free from combustible materials, 

gasoline, and other fl ammable vapors and liquids.

Remove jacket front and top panels and check for 

piping leaks around relief valve and other fi ttings. If 

found, contact qualifi ed service agency to repair. DO 

NOT use stop leak compounds.

Test relief valve. Refer to valve manufacturers 

instructions packaged with relief valve.

Visually inspect venting and air intake system for 

proper function, deterioration, or leakage. If vent or 

air intake show any signs of deterioration or leakage, 

contact a qualifi ed service agency to repair or replace 

immediately and to insure proper reassembly and 

resealing of vent and air intake system.

Visually inspect clear vinyl condensate lines and PVC 

condensate drain pipe for proper operation, leakage, 

and deterioration. If condensate lines or drain pipe 

show any signs of blockage, leakage, or deterioration 

contact a qualifi ed service agency to clean, repair, or 

replace them immediately.

Where low water cutoffs are used, periodic inspection of 

low water cut off is necessary, including fl ushing of fl oat 

type devices. Refer to low water cut off manufacturer’s 

specifi c instructions.

Follow instructions  “To Turn Off Gas To Appliance” on page 

38 .
If heating system is to remain out of service during 

freezing weather, and does not contain antifreeze, drain 

system completely. If boiler will be exposed to freezing 

temperatures, drain condensate lines. Otherwise, do not 

drain system or boiler.