6
CORAYVAC
®
HEATING SYSTEMS
Fuel Conversion Instructions
The CORAYVAC
®
burners operate with a "zero" regulator for both
propane and natural gas; they are factory set on a special flow
bench. Since each unit uses the same regulator, no spring changes
or adjustments are necessary when converting a CORAYVAC
®
burn-
er. Do Not Adjust The Zero Regulator.
Three separate conditions exist for converting between gases:
1. The CRV-B/E series, with the exception of the CRV-B/E-12 and
CRV-B/E-12A, are converted by changing the orifice only.
2. The CRV-B/E-12 and CRV-B/E-12A require a change of the
primary air shutter in addition to the orifice.
3. The CRV-B-2 is not convertible.
NOTE: There have been two different zero regulators used in the
CRV-B/E-9 and CRV-B-10 burners. The type of zero regula-
tor used will determine the orifice needed. If you are convert-
ing a CRV-B/E-9 or CRV-B-10 from propane to natural gas,
determine which regulator is being used in your burner (see
below).
The smaller Maxitrol R-400 regulator was in use beginning in
1991 and ending in March 1996 and was replaced exclusive-
ly by the R-500 at this time. The R-400 measures approxi-
mately 2" x 2" x 3"; the R-500 measures 3" x 3" x 4 1/2".
Each is clearly marked with the model number. See
Page 8,
Figure 3, for regulator location.
Use burner type and regulator type to determine the orifice
needed (See
Page 7, Table 3 ).
1. Insure that the gas supply and power are off before starting the
conversion.
2. Insure that power is shut off to the system/pump before
proceeding.
3. The installer is responsible to insure that the unit is gas tight
when returning the system to operation.
4. The CRV unit can easily be converted without removing the
burner unit from the combustion chamber. If the orifice falls off of
the hex key into the mixing chamber, it will be necessary to
remove the unit to get the orifice out. It is best to use a sharp
(new) hex key which will fit tightly into the orifice.
Introduction
General
Instructions/
Precautions
