Munchkin HIGH EFFICIENCY HEATER with the "925" Controller - Manual (Page 24)

24
PIPING
C. FILL AND PURGE HEATING SYSTEM
• Attach the hose to balance and purge hose connector or drain valve and run hose to near-
est drain
• Close the other side of the balance and purge valve or the shut off valve after the drain.
• Open first zone balance and purge or drain valve to let water flow out the hose. If zone
valves are used, open the valves one at a time manually. (Note: please check valve manu-
facturer’s instruction prior to opening valves manually, so as not to damage the valve.)
• Manually operate fill valve regulator. When water runs out of the hose, while it’s connect-
ed to the balance and purge valve or drain you will see a steady stream or water (with no
bubbles). Close balance and purge valve or drain to stop the water from flowing.
Disconnect the hose and connect it to next zone to be purged.
• Repeat this procedure for additional zones (one at time).
Upon completion, make sure that the fill valve is in automatic position and each zone balance and
purge or shut off is in an open position and zone valves are positioned for automatic operation.
1. Glycol in hydronic applications which is specially formulated for this purpose includes
inhibitors which prevent the glycol from attacking metallic system components. Make certain
that the system fluid is checked for the correct glycol concentration and inhibitor level.
2. The glycol solution should be tested at least once a year and as recommended by the glycol
manufacturer.
3. Anti-freeze solutions expand more than water. For example a 50% by volume solution
expands 4.8% in volume for a temperature increase from 32° F to 180° F, while water expands
3% with the same temperature rise. Allowances must be made for this expansion in the sys-
tem design.
4. A 30% mixture of glycol will result in a BTU output loss of 15% with a 5% increase in head
against system circulator.
5. A 50% mixture of glycol will result in a BTU output loss of 30% with a 50% increase in head
against system circulator.
CAUTION
For installation that incorporates standing Iron Radiation and systems with manual
vents at the high points. Follow above section and starting with the nearest manual
air vent, open vent until water flows out, then close vent. Repeat procedure, working
your way toward furthest air vent. It may be necessary to install a basket strainer in
an older system where larger amounts of sediment may be present. Annual cleaning
of the strainer may be necessary.
WARNING
Use only inhibited propylene glycol solutions which are specially formulated for
hydronic systems. Ethylene glycol is toxic and can attack gaskets and seals used in
hydronic systems.
CAUTION
It is highly recommended that you carefully follow the glycol manufacturer’s
recommended concentrations, expansion requirements and maintenance
recommendations (pH additive breakdown, inhibitor reduction, etc.). You must
carefully figure the additional friction loss in the system as well as the reduction in
heat transfer co-efficients.