Munchkin 399M - Manual (Page 17)

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VENTING / PIPING
G. CONDENSATE REQUIREMENTS
This is a condensing high efficiency appliance, therefore this unit has a condensate removal system.
Condensate is nothing more than water vapor, derived from the combustion products, similar to an
automobile when it is initially started. It is very important that the condensate line is sloped away
from and down to a suitable inside drain, if the condensate outlet on the Munchkin is lower than the
drain, you must use a condensate removal pump (kit available from Heat Transfer Products, Inc.) A
condensate filter, if required by local authorities can be made up of lime crystals, marble or
phosphate chips will neutralize the condensate. This can be done in the field by the installer or you
may purchase one from Heat Transfer Products, Inc. It is also very important that the condensate line
is not exposed to freezing temperatures, or any other type of blockage. Plastic tubing should be the
only material used for the condensate line. Steel, brass, copper or others will be subject to corrosion
or deterioration. A second vent may be necessary to prevent condensate line vacuum lock if a long
horizontal run is used. Also, an increase in pipe size may be necessary to drain properly. Support of
the condensation line may be necessary to avoid blockage of the condensate flow.
PART 5. PIPING
A. HYDRONIC PIPING WITH CIRCULATORS OR ZONE VALVES
The Munchkin is designed to function in a closed loop 15 PSI System. To assure you that you have
adequate pressure in the system, we have installed in the outlet manifold, a pressure switch that will
not let the Munchkin operate without a minimum of 10 PSI water pressure. This assures you that if the
system does have leak, the Munchkin will lock out (PRO on the display) before it damages the Stainless
Steel Heat Exchanger. We have also included a Temperature and Pressure gauge which should be
located on the Munchkin outlet to monitor the system pressure and outlet temperature from the
Munchkin. It is important to note that the Munchkin has a minimal amount of pressure drop and must
be figured in when sizing the circulators. Each Munchkin installation must have an Air Elimination
device which will remove air from the system. Install the Munchkin so the gas ignition system
components are protected from water (dripping, spraying, etc.) during appliance operation for basic
service of circulator replacement, valves and other. Observe minimum 1” clearance around all un-
insulated hot water pipes when openings around pipes are not protected by non-combustible
materials. On a Munchkin installed above radiation level, some states and local codes require a low
water cut off device at the time of installation. If the Munchkin 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. Freeze Protection for new or existing systems must use glycol that is specially formulated
for this purpose. It includes inhibitors, which prevent the glycol from attacking the metallic system
components. Make certain that the system fluid is checked for the correct glycol concentration and
inhibitor level. The system should be tested at least once a year and as recommend by the producer
of the glycol solution. Allowance should be made for the expansion of the glycol solution in the system
piping. Example 50% by volume solution expands 4.8% in volume for the temperature increase from
32 F to 180 F, while water expands 3% with the same temperature rise.
Basic steps are listed below, with Illustration, which will guide you through the installation of the
Munchkin.
1. Connect the system return marked “Heater In”, make sure to install with pipe sealant com-
CAUTION
The Munchkin should not be operated as a potable Hot Water Heater. It should not be
used as a direct Hot Water Heating Device.