Operator`s manual
  PUREHEAT™ HYDRONIC AIR HEATER OPERATOR’S MANUAL – SECTION 3 
V. 2, Rev. 09/01/06  © 2006 Ground Heaters, Inc. 3- 3 
3.1.1.3 O
2 
Content Sampling 
1.  Follow the combustion analyzer manufacturer’s instructions for pre-purge and exhaust sampling. 
  2.  Sample the exhaust gas
by inserting the combustion analyzer sampling probe into the chimney access 
hole provided through the exhaust guard. The
 probe must be greater than 5 in. (127 mm) in length for 
an
 accurate sampling. Exhaust O
2
 content must be 3 to 4% for optimum performance and minimum 
soot production. 
  3.  Several samples should be taken as the heater warms. The final sample should be taken just before 
the heater reaches 180ºF (82.2ºC). 
3.1.1.4 Smoke Spot Sampling
1.  Follow the smoke spot tester manufacturer’s instructions for accurate exhaust sampling. 
2.  Start the Burner by turning the BURNER Switch ON. The Burner will start and begin a 45 second pre-
purge followed by the ignition sequence 
3.  Sample the Burner exhaust for smoke
by inserting the smoke spot sampling probe into the chimney 
access hole provided through the exhaust guard. The
 probe must be greater than 5 in. (127 mm) in 
length
 for an accurate sampling. Smoke spot production must be 2 or less. 
4. 
Several samples should be taken as the heater warms. The final sample should be taken just before 
the heater reaches 180ºF (82.2ºC). 
NOTE: Higher O
2
 percentage (excess air settings) lowers soot production but raises stack temperature 
and reduces efficiency. Lower O
2
 percentage (inadequate air settings) increases efficiency and 
lowers stack temperature but may cause soot build-up. A Burner optimized for clean and efficient 
operation will have O
2
 levels of 3 to 4% and a smoke spot value of 1 or less. 
5.  Loosen the air dampers locking screws enough to provide movement for adjustment. Open the top 
damper 45%, and fully shut the bottom damper. (Refer to Appendix A-24) 
6.. Adjust the air dampers until combustion parameters fall within the above outlined values. 
7.  Lock the air dampers in place by tightening the locking screws. 
3.1.2 Burner Shutdown
1.  Shut down the Burner by turning the BURNER Switch OFF. 
2.  Turn MAIN BREAKER 1 and MAIN BREAKER 2 Switches OFF. 
3.  Shut the Main Gas Supply Ball Valve. Remove the manometers, petcocks and adapters, and reinstall 
pipe plugs (use pipe dope). 
NOTE:  Should the Burner fail to respond during any of the air adjustments or if the fuel pressure cannot 
be adjusted or drifts, discontinue Burner setup and contact your Pureheat™ Distributor. 
3.2 DIESEL/FUEL OIL
3.2.1 Burner Adjustment
Before beginning these steps, it is assumed that the optional diesel Burner has been installed per Section 
4.2.1. 
NOTE: The use of a high quality combustion analyzer and fuel pressure test gauge is mandatory
. All 
adjustments
 must be accomplished by an experienced fuel oil Burner professional and must 
conform
 to the requirements of local, state and federal codes and authorities. 










