Indirect Fired Water Heater Scalding; Hydronic Piping - Circulators, Zone Valves And Multiple Heaters - Pioneer PHR100-55 Instruction Manual

F. INDIRECT FIRED WATER HEATER SCALDING
This heater can deliver scalding water. Be careful
whenever using hot water to avoid scalding injury.
Certain appliances, such as dishwashers and
automatic clothes washers may require increased
water temperature. By setting the thermostat on this
heater to obtain the increased water temperature
required by these appliances, you may create the
potential for scald injury.
To protect against injury, you should install a mixing
valve in the water system. This valve will reduce
point of discharge temperature by mixing cold and
hot water in branch supply lines. Such valves are available from your local plumbing supplier.
Table 2 details the relationship of water temperature and time with regard to scald injury and may be used
as a guide in determining the safest water temperature for your applications.
G. HYDRONIC PIPING - CIRCULATORS, ZONE VALVES AND MULTIPLE HEATERS
This heater is designed to function in a closed loop 15 PSI System. A factory installed low water cut off
will ensure that you have adequate water in the system. We have also included a T&P gauge which
allows the user to monitor system pressure and outlet temperature from the heater.
Install the heater so the gas ignition system components are protected from water (dripping, spraying,
etc.) allowing clearance for basic service of circulator replacement, valves and other parts. Observe
minimum 1" clearance around all hot water pipes not protected by non-combustible materials.
On a heater installed above radiation level, some states and local codes require a low water cut off device
at the time of installation. If the heater supplies hot water to heating coils in air handler units, flow control
valves or other devices must be installed to prevent gravity circulation of heater water in the coils during
the cooling cycle. Chilled water medium must be piped in parallel with the heater.
Basic steps are listed below which will guide you through the installation of the heater.
1. Connect the system return marked "Return".
2. Connect the system supply marked "Supply".
3. Install purge and balance valve or shut off valve and drain on system return to purge air out of each
zone.
4. Install a back flow preventer on the cold feed make-up water line.
APPROXIMATE TIME /
TEMPERATURE RELATIONSHIPS IN SCALDS
o
120 F
o
125 F
o
130 F
o
135 F
o
140 F
o
145 F
o
150 F
o
155 F
Table 2
20
More than 5 minutes
1 ½ to 2 minutes
About 30 seconds
About 10 seconds
Less than 5 seconds
Less than 3 seconds
About 1 ½ seconds
About 1 second