LAARS Heating Systems
Page 32
Figure 16. DHW Piping - Two Heaters, Two Vertical Tanks
7.D Condensate Drain Trap
A condensate drain trap is included with the unit
and is designed to drain the unit of condensate.
See Figure 2 on page 8. The vent condensate
should be drained through a drain tee located in
the vent line. This will help prevent excessive
condensate from entering the unit at the vent.
The condensate drain must be installed to
prevent the accumulation of condensate. When
a condensate pump is not used, the tubing must
continuously slope downward toward the drain with
no spiraling.
7.E Water Flow
See Section 5 for water flow and head requirements.
Note - The head loss for the piping, fittings, and
accessories must be calculated and added to the
heater head loss to get the total required pump
head. An undersized pump will result in insufficient
flow. This can result in scale buildup and failure of
the heat exchanger.
Connect a 3/4” PVC pipe between the drain
connection and a floor drain (or condensate pump if a
floor drain is not accessible).
Consult local codes for the disposal method.
A condensate neutralizer is not included with the unit
and yet is almost always used. It is advised that the
unit be installed on a raised 4” concrete platform so
that there is sufficient elevation for the condensate
neutralizer below the included condensate trap. See
Figure 9 on page 25
CAUTION
Condensate is mildly acidic (pH
=
5), and may
harm some floor drains and/or pipes, particularly
those that are metal. Ensure that the drain,
drainpipe, and anything that will come in
contact with the condensate can withstand the
acidity, or neutralize the condensate before
disposal.
Damage caused by failure to
install a neutralizer kit or to adequately treat
condensate will not be the manufacturer’s
responsibility.
NOTES:
1. Optional CWMU & recirculation line location.
2. Locate NTV DHW sensor or remote aquastat well in lower 1/3 of tank.
3. Back Flow Preventer may be required. Check local codes.
4. Thermal expansion tank may be required. Check local codes.
5. Factory mounted pumps are sized for a max pipe length of 30’ total, 6-90° elbows, full pipe size.
6. CAUTION: Pump sizing must be based upon water hardness at job site.
NOTE:
This drawing shows
suggested piping
configuration and valving.
Check with local codes and
ordinances for additional
requirements.
EXPANSION
TANK
Location of pump
.
Location of pump
.
Optional location for
COLD WATER SUPPLY
EXPANSION
TANK
BUILDING
RETURN
BALL VALVE
(TYPICAL)
TWO HEATERS
WITH TWO VERTICAL TANKS
MGV-DOM3-2H2VT
KEY:
..
Check valve
Check valve
