Installation / Operation Instruction Manual

Pre-installation continued-

NOTICE

Increasing the boiler DOE heating capacity above the values

listed in Table 3 will not increase the rating of the water heater.

2. Circulator Sizing – Refer to Table 5 for the

corresponding pressure drop through the coil for the given

model. Calculate the pressure drop of all straight pipe and

fittings on the supply and return of the water heater at the

selected flow rate. Add the piping/fitting pressure drop to

the pressure drop through the water heater coil.

Select a circulator that will provide an appropriate flow

rate at the combined pressure drop.

SYSTEM ZONE CONTROL

The indirect-fired water heater must be installed as a zone

separate from the space heating system. The domestic hot

water zone’s piping and circulator must be sized for a

minimum flow rate with all zones in use and a maximum flow

rate with only the water heater in use. For this reason, the

preferred method of zone control is with circulators.

1. Circulators – With space heating zones using

circulators, the indirect-fired heater should be added as

an additional zone with a circulator.

2. Zone Valves – Select a valve with a low-pressure drop

to assure adequate flow through the water heater.

3. Hybrid – The space heating zone can be zoned using

zone valves and the indirect-fired heater zoned with a

circulator.

DOMESTIC HOT WATER PRIORITY

Two options are available, Priority and Non-Priority.

1. Priority – Demand for space heating is interrupted or

postponed until the domestic hot water demand is

satisfied. This option provides maximum delivery of

domestic hot water. Priority is recommended when: