Caution, Part 5 5-a. hydronic heat piping, B. fill and purge heating system – HTP Munchkin High Efficiency Heater User Manual
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PART 5
5-A. HYDRONIC HEAT PIPING
The Munchkin is designed to function in a closed loop 15 PSI System. To assure that there is adequate pressure in the system,
we have installed in the Outlet Manifold, a pressure switch which will not let the Munchkin operate without a minimum of 10
PSI water pressure. This assures that the system does not have a leak, which could cause damage to the Munchkin System. It
is Important to note that the Munchkin Boiler does have minimal amount of pressure drop and must be figured in when sizing
the circulator to the System (See Figure 7B). Each Munchkin System must have an Air Eliminator, which is designed to be
installed in the Boiler Return Pipe (boiler in) which will remove air from the Hydronic System. Always follow good piping
practices. Observe minimum 1" clearance to combustibles around all uninsulated hot water pipes or 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 by the installer. If the Munchkin supplies hot water to
heating coils in air handlers units, flow control valves or other devices must be installed to prevent gravity circulation of boiler
water in the coils during the cooling cycle.
Basic steps are listed below, with an Illustration, which will guide you through the installation of the Munchkin
1. Pipe properly. In accordance to (Figure 7A).
2. Connect system return marked "BOILER IN", make sure to install with pipe sealant compound. Threaded connection are
1…" NPT brass nipples.
3. Connect system supply marked "BOILER OUT". Make sure to install with pipe sealant compound. Threaded connection
are 1…" NPT brass nipple.
4. Install Purge and Balance Valve on system return.
5. Install Back Flow Preventer if required by local codes on system return.
6. Install Pump on system supply. Make sure pump is properly sized for piping loss.
7. Install on Cold Water Feed Pressure Reducing Valve. (15 PSI nominal on system return). Check temperature/ pressure
gauge should read minimum of 12 PSI.
8. Install Expansion Tank on system supply. Use appropriate size tank for volume of water in system.
9. Install Air Vent on system return.
10. Install Flow Check on system supply.
11. Install Drain Valve on system supply. Note Munchkin can not be drained of water without purging the unit with air
pressure 15 PSI minimum.
12. Install Temperature/ pressure gauge on system supply.
5-B. FILL AND PURGE HEATING SYSTEM
Attach hose to balance and purge hose connector and run to drain.
Close the other side of the balance and pur ge valve.
Open first zone balance and purge valve, so as to let the water flow out of the hose. If zone valves are used, open zone
valves one at a time, manually. (NOTE: please check manufacturers’ instructions prior to opening valves manually , so
not to damage valve.)
Manually operate fill valve regulator. When the water runs out of the hose, while it’s connected to the balance and
purge valve you will see a steady stream (with no air bubbles). Close balance and pur ge valve to stop the water from
flowing. Disconnect hose and connect to next zone to be pur ged.
Repeat procedure for additional zones (one at a time).
Upon completion, make sure that the fill valve is in automatic position and each zone balance and purge valve is in the open
position and zone valves are positioned for automatic operation.
CAUTION!!
THE MUNCHKIN SHOULD NOT BE OPERATED AS A PORTABLE HOT WATER HEATER.
IT IS NOT TO BE USED AS A DIRECT DOMESTIC HOT WATER APPLIANCE.
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