HTP Munchkin High Efficiency Heater - Manual (Page 6)

It is recommended that a soapy solution be used to detect leaks. Bubbles will appear on pipe to indicate a leak is present. The
gas piping must be sized for the proper flow and length of pipe, to avoid pressure drop. Both the gas meter and the gas
regulator must be properly sized for the total gas load. If you experience a pressure drop greater than 1" WC, the meter or
regulator or gas line is undersized or in need of service. You can attach a meter to the incoming gas drip leg, by removing the
cap and installing the meter. The gas pressure must remain between 7" and 14" during stand-by and unit running heat cycle.
If an in-line regulator is used, it must be a minimum of 10 feet from the Munchkin. It is very important that the gas line is
properly purged by the gas supplier or utility. Failure to properly purge the lines or improper line sizing, will result in
the failure of the Munchkin lighting off.
This problem is especially noticeable in NEW LP installations, and also in empty
tank situations. This can also occur when a utility company shuts off service to an area to provide maintenance to their lines.
This valve must not be replaced with a conventional valve under any circumstances. As an additional safety feature, this
valve has a flanged connection to the Venturi and blower.
PART 4
VENTING
4-A. ALL MODELS 3" VENTED
The inlet pipe on the back of the cabinet, use 3" PVC schedule 40. It is very important that you plan the location properly, to
eliminate long pipe runs and excessive fittings. Inlet pipe size must not be reduced. Do not combine the inlet air with any
other inlet pipe including an inlet to an additional similar appliance. The joints must be properly cleaned, primed, and
cemented. The piping must also be properly supported as per Local and National Standard Plumbing Codes. It is important
that the piping must be clean and free from burs, debris, ragged ends, and particles of PVC.
Exhaust pipe on the back of the cabinet will use 3" PVC, CPVC, ABS Schedule 40 or 80. For concrete construction or to
meet certain fire codes, exhaust piping inlet air pipe must be 3" CPVC Schedule 40 or 80, (only to meet local fire codes). The
balance of the inlet and exhaust piping may be PVC Schedule 40 or 80, or ABS solid only, NOT FOAM CORE.
The only approved exhaust vent materials are PVC Schedule 40 (NOT FOAM CORE PIPE!). Exhaust piping should be
sloped back to the connection on the Munchkin, at least …" per foot to remove additional condensate that forms within the
pipe. The total combined length of pipe (intake piping plus exhaust piping added together) including elbow allowances intake
and exhaust (each elbow = 5’ of pipe) should not exceed 85’. The combined vent length should not be less than a combined
length of 6’ plus two 90 degree elbows. Choose your vent termination locations carefully. You must additionally make certain
that exhaust gas does not re-circulate back into the intake pipe. You must place them in an open area, and follow the
following guidelines.
1) Never vent into a walkway, patio area, alley or otherwise public area less than 7’ from
the ground.
2) Never vent over or under a window or over a doorway.
3) Never install a heat saver or similar product to capture waste heat from exhaust.
4) Always have vent location at least 1’ above maximum snow level.
5) Always have vent 1’ above ground level, away from shrubs and bushes.
6) Follow local gas codes in your region or refer to National Fuel Gas Code, Can B149.
7) Always have vent at least 3’ from an inside corner of outside walls.
8) Maintain at least 4’ clearance to electric, gas meters, and exhaust fans or inlets.
9)
Very Important!
Inlet air must be taken from outside of building, next to exhaust
outlet, no closer than 8".
10) Always place screens in all openings in intake and exhaust to prevent foreign matter
from entering the Munchkin.
11) The vent intake and exhaust must be properly cleaned and glued for a pressure tight joint. Several methods
for venting the Munchkin can be found in Figures 1 thru 6. Use the following layout as a guideline; certain
site conditions such as multiple roof lines/pitches may require venting modifications (consult factory). The
air inlet must be a minimum of 1’ vertically above the maximum snow level or 24" which ever is greater.
The air inlet must also be a minimum of 10’ horizontally from the roof, and terminated with a tee. The
exhaust must be a minimum of 24" above the air inlet opening and terminated with a coupling. It is very
important that there are no other vents, chimneys or air inlets in any direction for at least 4’.
WARNING!!
It is extremely important to follow these venting instructions exactly. Failure to
follow the venting instructions can cause severe personal injury, death or
substantial property damage.
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