Weil-McLain Electric Water Heater Install boiler-to-water heater piping, heating application

PLUS Line Instruction Manual Supplement

PLUS & PLUS WATER HEATERS WITH GAS-FIRED WATER BOILERS

2 Install boiler-to-water heater piping

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.

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.

Figure 4 Boiler-to-water heater piping:	Figure 5 Boiler-to-water heater piping:
Combined space heating/water	Dedicated water-heating only
heating application	application

3Boiler relief valve (see Boiler Manual for piping details)

4Relief valve discharge piping (see Boiler Manual for details)

5Water heater circulator — must be at least equal in capacity to circulator recommended in Table 1, page 7

6Isolation valves

10Flow/check valve (with weighted seat to prevent gravity circulation)

11Purge/drain valves

3Boiler relief valve (see Boiler Manual for piping details)

4Relief valve discharge piping (see Boiler Manual for details)

5Water heater circulator — (see Table 2, page 7)

8Expansion tank (diaphragm or bladder type)

6Isolation valves

10Flow/check valve (with weighted seat)

11Purge/drain valve

20 Fill line to fill valve (item 23)

6 Part number IWHA016A/1103