Sequence Of Operation; Draft-Proving Switch; Replacement Parts - Rheem Raypak D-2 Power Vent Installation And Operation Manual

8. SEQUENCE OF
OPERATION
On call for heat, the PC board will go through its safety
chain (water pressure switch, high limit 1 & 2, roll-out,
etc.). When the safety chain is closed, the IID pilot will
begin to spark and the pilot gas valve will open. A flame
will be lit at the pilot assembly. When an acceptable signal
is sent back to the PC board, proving the rectification, the
D-2 Power Vent blower will start. When the blower comes
up to speed, a draft-proving switch will close to allow the
main gas valve on the heater to open.
NOTE: On Low NOx units, the main gas valve &
combustion blower will turn on simultaneously. A heater
with a D-2 Power Vent will continue to operate until call
for heat is satisfied.

9. DRAFT-PROVING SWITCH

The draft-proving switch ensures that the blower is
operating. Once the D-2 Power Vent is wired to the heater,
the switch does not allow the PC board to open the main
gas valve, unless it is closed.
Figure 31. Draft-Proving Switch
22
APPROVED

10. REPLACEMENT PARTS

NOTE: To supply you with the correct part, it is important
that you supply the heater model number, serial number
and type of gas when applicable.
Any part returned for replacement under standard company
warranties must be properly tagged with a return parts tag,
completely filled in with the heater serial number, model
number, etc., and shipped to the Company freight prepaid.
If determined defective by the Company and within
warranty, a like part or equal substitution will be returned,
freight collect. Credit will not be issued.
MANUFACTURER:
UNCONTROLLED DOCUMENT IF PRINTED
2151 EASTMAN AVENUE
OXNARD, CA 93030