What To Do In Case Of Failure; General; Fault Overview - A.O. Smith COF 199 Installation, User And Service Manual

4. WHAT TO DO IN CASE OF FAILURE

4.1

General

If faults occur, check the following points:
• Overheat thermostat
The water heaters are equipped with an overheating
cut-out, which, in the case of a too high water
temperature, interrupts the current supply to
the burner, as a result of which the gas valves in the
gas block are closed and the gas supply is cut off.
The overheating cut-out remains activated until the
water temperature drops below the overheating
cut-out's switching-off point. Then the water
heater can be turned on again by resetting
the overheating cut-out. Next set the control
thermostat to a lower water temperature,
(see figure 8).
• Water temperature too high:
Check if the control thermostat has been set too high.
• Wrong hot water temperature:
1. Check the control thermostat setting;
2. Check that there are no leaks or if any taps are
open.
4.2

Fault overview

Fault Possible cause
Heater is off or Chimney is blocked.
does not ignite
Overheating cut-out is activated.
Gas or oil supply shut off.
Insufficient hot Temperature set too low.
water or none
at all Overheating cut-out is activated.
Supply of hot water exhausted.
Cause cannot be traced.
Water leakage Insufficient sealing of the water
connections (screw thread).
Leakage from another water appliance
or pipes in neighbourhood.
Please consult the front-mounted burner's installation
manual in the event of faults in the front-mounted burner.
Figure 8: Resetting the overheating cut-out
Measure
Trace (or let trace) cause and rectify it.
Let water in heater cool down and set the water
temperature to a lower value. Reset the overheating cut-out.
Let heater ignite.
Open gas or oil valve.
Set water temperature to higher value.
Reset overheating cut-out after the water has cooled down
and set the water temperature to a lower value.
Reduce hot water use. Give the heater time to heat up the
water.
Remove voltage supply. Close gas / oil supply valve and
contact your installer.
Tighten the screw thread connections.
Trace the cause.
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