Operational Problems

Read and understand this instruction manual and the safety messages herein before installing, operating or servicing this water heater.

Failure to follow these instructions and safety messages could result in death or serious injury.

This manual must remain with the water heater.

This section of the manual is intended to be an aid in correcting common operational problems, it is not all inclusive. The installer may be able to observe and correct certain problems which might arise when the water heater is first put into operation or when it is re-fired after a prolonged shutdown. However, only qualified service agents, as defined in Qualifications on page 6, using appropriate test equipment, should perform any service procedures on the water heater.

Note: Call the technical support phone number listed on the back cover of this manual for further technical assistance or to locate a qualified service agent in your area.

Installation Errors

Operational problems on new installations are often the result of installation requirements that have been overlooked rather than failed components. IE: A "Low Gas Pressure" Fault condition is most often caused by low supply gas pressure rather than a defective Low Gas Pressure switch. Rough starting and rough operation are often caused by undersized supply gas lines and/ or the absence of a supply gas regulator at the water heater.

Prior to performing any operational checks inspect the water heater installation to ensure all installation requirements and instructions have been maintained and followed. See the Installation Checklist on page 54

Note: Costs to correct installation errors are not covered under the limited warranty.

Rough Starting, Rough Operation

Fire and Explosion Hazard

Do not use water heater with any gas other than the gas shown on the rating label.

Excessive gas pressure to gas valve can cause serious injury or death.

Turn off gas lines during installation.

Contact a qualified installer or service agency for installation and service.

•Undersized supply gas line (low volume of supply gas) - see Supply Gas Line on page 13.

•Supply gas regulator is not installed per installation requirements (erratic gas supply volume/pressures) - see Supply Gas Regulator on page 13.

•Excessive supply gas pressure - see Table 4 on page 13 and Supply Gas Pressure Adjustment on page 51.

•Excessive manifold gas pressure - see Table 4 on page 13 and Manifold Gas Pressure Adjustment on page 51.

•Vent (exhaust) gas recirculation at the vent and intake air pipe terminations on Direct Vent installations - see Direct Vent Installation on page 23.

•Excessive equivalent lengths of intake air and/or vent (exhaust) piping installed - see Venting Requirements on page 22.

•Debris clogging/blocking the intake air screen(s) - see Figure 17 on page 24 and Figure 22 on page 26.

•Debris clogging/blocking the Main Burner - see Figure 2 on page 7.

Momentary Ignition

CAUTION

Burn Hazard

•The combustion chamber and burner sleeve and housing become very hot during operation.

•Do not reach into the burner housing or combustion chamber if the water heater

is still hot.

• Allow the water heater to cool and always use gloves when handling the main burner.

If the Main Burner ignites momentarily but does not sustain ignition allow the water heater to try to ignite up to two more times until control system locks out and the Ignition Failure Fault message is displayed on the control system's LCD. If the water heater is experiencing rough starts - see Rough Starting, Rough Operation on this page. For momentary ignition problems without rough starting check the following:

•Incorrect manifold gas pressure - see Table 4 on page 13 and Manifold Gas Pressure Adjustment on page 51.

•Undersized supply gas line (low volume of supply gas) - see Supply Gas Line on page 13.

•Supply gas regulator is not installed per installation requirements (erratic gas supply volume/pressures) - see Supply Gas Regulator on page 13.

•See the list of possible causes and things to check and repair for the Ignition Failure Fault message on page 58.

•Debris clogging/blocking the intake air screen(s) - see Figure 17 on page 24 and Figure 22 on page 26.

•Debris clogging/blocking the Main Burner - see Figure 2 on page 7.

Not Enough Or No Hot Water

•No power to the water heater, check breaker, fuses and the water heater on/off switch.

•Hot water supply valve(s) to fixtures closed.

•Operating Set Point is set too low, Differential setting is set too high. See Control System Operation on page 42.

•Upper and/or Lower Probe Offset settings are causing the heating cycles to terminate prematurely - see Temperatures Menu (cont) on page 46.

•Ensure there is not any external supervisory control (using the enable/disable circuit) disabling heating operation. See Enable/Disable Circuit on page 39.

•The heating capacity of the water heater has been exceeded, the water heater is unable to meet demand.