Crown Boiler 24-07 用户手册

41

 CONNECT TANKLESS HEATER PIPING as 

shown in Figure 38.  See Table IV for Tankless Heater 

Ratings.

1.  Install Flow Regulator 
  If flow through the heater is greater than its rating, 

the supply of adequate hot water may not be able to 

keep up with the demand.  For this reason a FLOW 

REGULATOR matching the heater rating should be 

installed in the cold water line to the heater.  Refer 

to Figure 36 for piping recommendations.  Locate 

the flow regulator below the inlet (cold water side) 

of the heater and a minimum of 36” away from the 

inlet so that the regulator is not subjected to excess 

temperatures during “off” periods when it is possible 

for heat to be conducted back through the supply 

line.  The flow regulator will limit the flow of supply 

water regardless of inlet pressure variations ranging 

from 20 to 125 psi.

2.  Install Water Temperature Mixing Valve

  Refer to Figure 38 for piping recommendations.  

Adjust and maintain the mixing valve in accordance 

with manufacturer’s instructions. 

  Installation of a mixing valve will also lengthen the 

delivery of the available hot water by mixing some 

cold water with the hot.  In addition, savings of hot 

water will be achieved since the user will not waste 

as much hot water while seeking desired water 

temperature.  Higher temperature hot water required 

by dishwashers and automatic washers is possible 

by piping the hot water from the heater prior to 

entering the mixing valve.  An electric hot water 

booster can also be used.  The mixing valve should 

be “trapped” by installing it below the cold water 

inlet to heater to prevent lime formation in the valve.

3.  Flushing of Heater 

All water contains some sediment which settles 

on the inside of the coil.  Consequently, the heater 

should be periodically backwashed.  This is 

accomplished by installing hose bibs as illustrated 

in Figure 38 and allowing water at city pressure to 

run into hose bib A, through the heater, and out hose 

bib B until the discharge is clear.  The tees in which 

the hose bibs are located should be the same size as 

heater connections to minimize pressure drop.

4.  Hard Water
  A water analysis is necessary to determine the 

hardness of your potable water. This is applicable 

to some city water and particularly to well water. 

An appropriate water softener should be installed 

based on the analysis and dealer’s recommendation. 

This is not only beneficial to the tankless heater but 

to piping and fixtures plus the many other benefits 

derived from soft water.

67

35-1/2"

-

64

-

37-1/2"

150

-

40"

Primary or Secondary

Primary (Gravity Return)

Primary (Pumped Return)

“A”

“B”