Rheem IKONIC RTGH-S11i Training And Service Manual page 55

ERROR CODE DIAGNOSTICS
2.2 ERROR CODE LIST
A090 ERROR CODE
Detected Blockage in Venting
If the water heater detects a blockage in the venting,
the water heater displays the "A090" error code on the
Liquid Crystal Display (LCD) on the User Interface.
Diagnostic check items
• Venting
• Air filter
• Gas inlet pressure
Check method
Venting
Check the condition of venting (Exp. The connections
of vents, the terminal vent top) If the connection of
venting is removed or the terminal vent top is blocked
by something, reconnect the vents or clean the termi-
nal vent top (Both inlet side and exhaust side)
Refer to section "1.1.2 Venting for direct vent water
heat" in this manual or refer to U&C manual for instal-
lation instructions.
Air filter
Check with the air filter at the inlet air connection of the
water heater that filter is not blocked by some foreign
substance.
If the air filter is closed by something, clean the air filter
and remove the cause to be blocked the air filter.
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IKONIC Tankless Water Heater Service Manual
Gas supply pressure
1. Check the gas supply pressure at the gas connec-
tion of the water heater.
The correct gas pressure are below;
• Natural Gas (NG); 4.0"-10.0" W.C
• Liquid Propane (LP); 8.0"-13.0" W.C
2. While the static pressure is normal, the use of an-
other gas appliance may cause a possible drop to
the water heater. Therefore, it is required to check
the dynamic pressure.
• Static pressure : Gas pressure during standby
• Dynamic pressure : Gas pressure at max combus-
tion