Dual Venturi - Navien NCB-700-2S+/42K Service Manual

4.7.17 Dual venturi

Item
Function
Fault
Symptoms
Error codes
Diagnostics
Controls the TDR by adjusting the gas / air mixture rate.
A synchronous motor is used to provide two control phases for mixing gases.
1. Blades will not close.
2. Blades will not open.
1. Boiler operation starts and stops frequently because of excessive heat supply.
2. Set point temperature is not reached because of insufficient heat.
E060
Voltage test: Test the voltage at the synchronous motor.
(After approx. 2 sec the blade opening or closing, the motor turns off.)
Description
<Closed>
<Open>
System Details 59