A.O. Smith FMD 40 Manuale Utente

26

These guidelines should be utilized by a qualifi ed service agent.

 

Improperly sealed, hot or cold supply connection,  

Tighten threaded connections.

 

 

relief valve, drain valve, or thermostat threads.

 

 

Leakage from other appliances or water lines. 

Inspect other appliances near water heater.

   Condensation 

of 

fl ue products. 

Refer to CONDENSATION.

 

 

Thermal expansion in closed water system. 

Install thermal expansion tank (DO NOT plug T&P valve).

 

 

Improperly seated valve. 

Check relief valve for proper operation 

 

 

 

(DO NOT plug T&P valve).

 

 

High sulfate or mineral content in water supply. 

Drain and fl ush heater thoroughly, then refi ll.

 

 

Bacteria in water supply. 

Chlorinate or aerate water supply.

 

 

Dirty pilot burner. 

Clean pilot assembly. 

 

 

 

Thermocouple tip is not in contact with pilot fl ame. 

Insert thermocouple correctly. 

 

 

Thermocouple malfunction. 

Replace thermocouple. 

 

 

Thermocouple malfunction. 

Check thermostat. 

 

 

Gas knob dial not positioned correctly. 

Refer to LIGHTING INSTRUCTIONS. 

   Pilot 

orifi ce clogged. 

Clean or replace pilot orifi ce.

 

 

Pinched or clogged pilot tube. 

Replace pilot tube.

 

 

Main gas supply off. 

Turn on main gas shut-off valve. 

 

 

 

Heater not lit or thermostat not on. 

Refer to LIGHTING INSTRUCTIONS.

 

 

Thermostat set too low. 

Refer to TEMPERATURE REGULATION.

 

 

Heater undersized. 

Reduce the hot water use.

 

 

Low gas pressure. 

Contact dealer.

 

 

Incoming water is unusually cold. 

Allow more time for heater to re-heat.

 

 

Leaking hot water pipes or fi xtures. 

Have a plumber check and repair leaks.

 

 

High temperature limit switch activated. 

Contact a Service Agency to determine cause.

 

 

Thermostat set too high. 

Refer to HIGH TEMPERATURE REGULATION.

 

 

Condensate dripping on burner. 

Refer to CONDENSATE.

 

 

Sediment at bottom of heater tank. 

Clean sediment from tank. Refer to DRAINING instructions

 

 

 

in Maintenance section of manual.

 

 

Improper combustion. 

Refer to FACTS TO CONSIDER ABOUT THE LOCATION.

 

 

 

Also see Figure 2 on page 6.