PVI Industries MAXIM INTEGRATED WATER HEATING SYSTEM User Manual

12

AXIAL FLOW GAS BURNER (continued) 

 
C.  Defective automatic main or auxiliary gas 

shut off valves. Check electrical circuitry to 
valves. Replace valves or correct circuitry as 
required. 

 

D.  Main diaphragm shut off valve opening too 

slowly. Adjust bleed on valve. 

 

E.  Defective flame safeguard control or plug on 

amplifier. Check and replace as required. 

 

F.  Main gas pressure regulator atmospheric 

vent line obstructed. Correct. 

 

G.  Defective main gas pressure regulator. 

Replace.  Misadjusted main gas pressure  
regulator. Readjust to meet required 
operational values. 

 

H.  Polarity reversed on incoming power. (S89 

control only) 

 

5. CARBON MONOXIDE READINGS ON GAS FIRING 

 

A.  Flame impingement on "cold" heat transfer 

surfaces caused by excessive firing rate. 
Reduce firing rate to correct input volume. 

 

B.  Incorrect gas/air ratios. Readjust burner to 

correct CO

2

/O

2

 levels, eliminated all CO 

formation. 

 
 

6. GAS HIGH FIRE INPUT CANNOT BE ACHIEVED 

 

A.  Gas company pressure regulator or meter 

operating incorrectly, not allowing required 
gas pressure at burner train inlet. Contact gas 
company to correct. 

 

B.  Gas cock upstream of train inlet not fully 

open. Check and correct. 

 

C.  Gas line obstructed. Check and correct. 

 

D.  Gas train main and/or lead test cocks not 

fully open. Check and correct. 

 

E.  Gas supply line between gas company 

regulator and burner inlet too small. Check 
supply pressure at meter, determine pressure 
drop and increase line size as required, or raise 
supply pressure to compensate for small line. Do 
not raise pressure so high that under static (no 
flow) conditions the pressure exceeds the 
maximum allowable pressure to the gas train 
components on the burner. 

 

F.  Burner gas train components sized too small 

for supply pressure. Increase component size 
as appropriate or consult factory. 

 

G.  Automatic gas valve not opening fully due to 

defective operation. Replace gas valve. 

 

H.  Orifice (if supplied) too small. Replace with 

correct size. 

 

I. 

Defective main gas pressure regulator. 
Replace. 

 

J.  Incorrect spring in main gas pressure 

regulator. Replace as required. 

 

K.  Main gas pressure regulator vent line 

obstructed. Check and correct. 

 

L.  Normally open vent valve (if supplied) not 

closing when automatic gas valves open. 
Check to see if valve is fully closed when 
automatic valves are open. Replace vent valve, 
if not closing fully.