Cleveland ogb-20.20 Manuale Utente

•  If the condensate box is heated to 140 degrees F at the B3probe, 120 VAC is 

sent from terminal 5 of connector X12 to the condenser valve (Y1) until the 
temperature drops.  

b

  The display will show the set temperature and set time when the flush is done or a 

negative reply is made to the “Generator Flush?”. 

c

  The Control Board (A10) will check the water level by looking for a ground at 

terminals 1 and 2 on connector X15.  These are connected to the high and low 
probes (B1) in the steam generator. 
•  If the ground is not found 120 VAC is sent from terminal 7 on connector X12 

on the Control Board (A10) to the fill solenoid (Y3) 

•  The fill solenoid opens and the generator is filled until both probes are 

grounded. 
◊

  If the top probe becomes ungrounded for more that 5 seconds the fill 

solenoid (Y3) will energize. 

◊

  If the bottom probe becomes ungrounded the combi will fill immediately 

and the combi will not heat 

d

  When terminal 2 on connector X15 is grounded, the Control Board (A10) sends 

120 VAC to 
•  The primary of the Hot Air 24v Transformer (T1) 

◊

  24 VAC is sent from the secondary of the transformer to the Hot air 

Burner Control (N20) 

•  The primary of the Steam 24v Transformer (T2) 

◊

  24 VAC is sent from the secondary of the transformer to the Steam Burner 

Control (N21) 

•  Terminal 1 on connector X20 of the Gas Control Board (A20) 

•  Terminal 12 on connector X1 of the Upper Hot Air Control Module (N20) 

•  Terminal 12 on connector X1 of the Steam Control Module (N22) 

•  Terminal 12 on connector X1 of the Lower Hot Air Control Module (N22) 

e

  If the Steam Generator temperature is less than 190 dgrees the Control board 

transmits and receives a signal from terminals 5,6,7 and 8 on connector X10 to 
terminals 3,4,5 and 6 of connector X28 on the Gas Board (A20) 
•  The Gas Board (A20) begins the steam generator heat circuit 

◊

  A signal is sent from terminal 8 of connector X24 to terminal 4 of 

connector X2 on the Steam Power Burner and Fan Control (U21) selecting 
the set speed of the combustion blower. 
(a)

 When this speed is attained the signal is sent from terminal 2 of 

connector X2 on the Steam Power Burner and Fan Control (U21) to 
terminal 9 of connector X24 on the Gas Board (A20) 

◊

  A request for heat is sent from terminal 3 of connector X21 on the Gas 

Board (A20) to terminal 10 on connector X1 on the Steam Burner Control 
Module (N21) 
(a)

 120 VAC is sent from terminal 8 of connector X1 of the Steam Burner 

Control Module through the high limit (B7.2) to terminal 7 of 
connector X1 of the Steam Burner Control Module