Aqua-Hot 375-d Service Manual page 34

Replacement Procedure:
F
AILURE TO DISCONNECT ALL POWER SUPPLIES AND
TO ALLOW THE HEATER TO COOL BEFORE SERVICING
COULD CAUSE SERIOUS DAMAGE OR PERSONAL INJURY
1. Ensure that the Aqua-Hot has been completely shut
down and that all power sources have been disconnect-
ed. Also, because this replacement procedure will in-
volve the potential for hot coolant, be sure the heater is
adequately cooled.
2. Drain the antifreeze and water heating solution from the
Aqua-Hot's boiler tank using the drain valve.
3. Disconnect the defective zone pump's wires by separat-
ing the quick-disconnect terminals. Reference Figure
19.
4. Release the nylatch plungers securing pump to heater.
5. Using constant tension pliers, loosen and slide back the
constant tension clamps securing the hoses to the zone
pump.
Zone Pump 2
Zone Pump 1
/
OR
®
© 2009 Aqua-Hot 375D Hydronic Heating System Service Manual—Rev. A
S 4: A
ECTION QUA
6. Remove the hoses from the defective zone pump.
6. Slide the hoses back onto the replacement zone pump
and set the constant tension clamps back into place.
7. Install the replacement zone pump onto the heater, by
aligning nylatch plungers into holes, and pushing in but-
ton to secure pump.
8. Reconnect the wires on the replacement zone pump to the
wires connected to the heater by uniting the red quick-
disconnect terminals.
9. Refill the Aqua-Hot's boiler tank with the antifreeze and
water heating solution. Reference Section 5 for filling i-
nstructions.
10.
Test the Aqua-Hot for normal operation.
Figure 19
-H C
OT OMPONENTS
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