Model DP Oil-Fired Heater
Page 11
5.3 Automatic Flow Control Valve
The inlet/outlet header of the XL-3 heater comes
equipped with an automatic flow control valve. The
automatic flow control valve maintains the proper flow
through the heater at rates up to approximately 60
Gallons Per Minute (GPM) (227 liters per minute
[LPM]). If the filter system flow rate is higher than
approximately 60 GPM (227 LPM), install a manual
bypass valve (see Figure 9), then perform a
temperature rise test (see Section 7.7) and adjust the
flow using the bypass valve until the proper
temperature rise is obtained.
5.4 Reversible Water Connections
The XL-3 heater is shipped with water
connections on the right side, but changing the
connections to the left side could simplify the
installation or improve access for service and
maintenance. Make the change before locating and
connecting the heater. This procedure for reversing
the connections involves removing the heat exchanger
and reinstalling it turned 180° from it's original position.
Some of the heater wiring and control components
must be relocated, so this procedure must be done only
by a qualified service technician.
Heat exchanger reversals are generally done
before the installation of power and water to the
heater. If you need to reverse the heat exchanger on a
previously installed heater be sure that all electrical
power, the gas supply and water supply have been
turned off before starting the procedure.
Follow these step-by-step instructions and
Figures 10 and 11 to reverse the heat exchanger:
Figure 9. Water Piping.
Manual bypass is used
only when filtration rate
normally exceeds
60 gallons per minute
Thermometer For
Testing Temperature
Rise
1. Remove the control compartment door.
2. Remove the chimney cap assembly, or
barometric draft control if one is installed, and the
inner stack (1).
3. Remove the eight screws (2) securing the top
assembly and lift off.
4. Lift out the flue collector assembly (3).
5. Lift off both heat exchanger end baffles (4).
6. Remove the siphon loop cover (5) located on the
right side of the heater under the In-Out header.
7. Remove both gap spacers (6).
8. Disconnect the siphon loop from the header (7).
9. Remove both drain extensions (8) (one at each
side of the heat exchanger) and the 1/4" plug (9).
10. Carefully remove the insulation at each corner of
the heat exchanger; it will be reused. Remove
the four hold-down screws (10).
11. Unplug the electrical connector at the switch box
inside the control compartment (11). At the other
end of the conduit, loosen the brass compression
fitting one or two turns. Rotate the conduit
assembly and lay it on top of the heat exchanger.
WARNING
The heat exchange is heavy. FOR YOUR SAFETY it
may be necessary to have help lifting the heat
exchange out of the heater and replacing it.