Weil-McLain Ultra Electric Water Heater - Manual (Page 6)

Part number IWHA016A/1103
6
PLUS Line Instruction Manual Supplement
PLUS & PLUS
WATER HEATERS WITH GAS
-
FIRED WATER BOILERS
Install boiler-to-water heater piping
2
Combined space heating/water
heating applications
1. Figure 4 shows recommended piping between Ultra
Boiler and PLUS water heater. All show direct
connection of the water heater piping to the boiler
because the boiler circulator shuts down during
water heater operation.
2. Table 1, page 7, uses the recommended flow rates
for the Ultra PLUS water heater and minimum flow
rates for the Ultra boiler to provide recommended
water heater piping and circulator sizing. If using
another circulator, verify it is at least equal to the
Taco selection given in Table 1. For general
information on head loss through boiler and boiler-
to-water heater piping, refer to the Ultra Boiler
Manual.
3. Procedure :
Step 1 : Select Ultra Boiler model and PLUS water
heater model in Table 1.
Step 2 : Read recommended minimum flow rate, GPM,
in table.
Step 3 : Read across to find recommended minimum
pipe size for boiler-to-water heater piping.
Step 4 : Read across to find recommended Taco
circulator model. Use a circulator with a pump
curve at least equal to the Taco circulator shown.
See Figure 6, page 7 for pump curves of typical
Taco circulators.
Figure 4 Boiler-to-water heater piping:
Combined space heating/water
heating application
3 Boiler relief valve (see Boiler Manual for piping details)
4 Relief valve discharge piping (see Boiler Manual for details)
5 Water heater circulator — must be at least equal in capacity to
circulator recommended in Table 1, page 7
6 Isolation valves
10 Flow/check valve (with weighted seat to prevent gravity circulation)
11 Purge/drain valves
Figure 5 Boiler-to-water heater piping:
Dedicated water-heating only
application
Dedicated water-heating only
applications
1. Figure 5 shows recommended piping between Ultra
Plus Boiler and PLUS water heater for dedicated
water-heating only applications.
2. Pipe sizing :
Table 2, page 7, provides the recommended
minimum pipe size for boiler-to-water heater piping.
3. Circulator :
Use the circulator recommended in Table 2, page 7.
Install the circulator as shown in Figure 5.
4. Procedure :
Step 1 : Select Ultra Boiler model and PLUS water
heater model in Table 1, page 7.
Step 2 : Read flow rate expected using the circulator
specified inthe last column.
Step 3 : Size connecting piping as listed under
“Boiler piping” in the table.
3 Boiler relief valve (see Boiler Manual for piping details)
4 Relief valve discharge piping (see Boiler Manual for details)
5 Water heater circulator — (see Table 2, page 7)
8 Expansion tank (diaphragm or bladder type)
6 Isolation valves
10 Flow/check valve (with weighted seat)
11 Purge/drain valve
20 Fill line to fill valve (item 23)