Munchkin Gas-Fired Hot Water Circulating Heater - Manual (Page 53)

52
GAS-FIRED HEATER
Installation Manual
PART 11. START-UP PREPARATION
(CONTINUED)
5. The system may have residual substances
that could affect water chemistry. After the
system has been filled and leak tested, verify
water pH and chlorine concentrations are
acceptable.
D. PURGE AIR FROM WATER SYSTEM
1. Purge air from system:
a. Connect a hose to the purge valve and
route hose to an area where water can
drain and be seen.
b. Close the heater or system isolation valve
between the purge valve and fill
connection to the system.
c. Close zone isolation valves.
d. Open quick-fill valve on cold water make-
up line.
e. Open purge valve.
f.
One zone at a time, open the isolation
valves. Allow water to run through the
zone, pushing out the air. Run until no
noticeable air flow is present. Close the
zone isolation valves and proceed with
the next zone. Follow this procedure until
all zones are purged.
g. Close the quick-fill water valve and purge
valve and remove the hose. Open all
isolation valves. Watch that system
pressure rises to correct cold-fill
pressure.
h. After the system has operated for a
while, eliminate any residual air by using
the manual air vents located throughout
the system.
i. If purge valves are not installed in
system, open manual air vents in system
one at a time, beginning with lowest
floor. Close vent when water squirts out.
Repeat with remaining vents.
j. Refill to correct pressure.
E. CHECK FOR GAS LEAKS
F. CHECK THERMOSTAT CIRCUIT(S)
1. Disconnect the two external wires connected
to the heater thermostat terminals (low
voltage terminal strip terminals 5 and 6).
2. Connect a voltmeter across these two
incoming wires. Close each thermostat, zone
valve and relay in the external circuit one at
a time and check the voltmeter reading
across the incoming wires.
3. There should NEVER be a voltage reading.
4. If a voltage does occur under any condition,
check and correct the external wiring. (This is
a common problem when using 3-wire zone
valves.)
5. Once the external thermostat circuit wiring is
checked and corrected if necessary,
reconnect the external thermostat circuit
wires to heater low voltage terminal strip
Allow the heater to cycle.
WARNING
Before starting the Munchkin Contender, and
during initial operation, smell near the floor and
around the heater for gas odorant or any
unusual odor. Remove heater front door and
smell interior of heater enclosure. Do not
proceed with startup if there is any indication of
a gas leak. Repair any leak at once.
WARNING
Propane heater only — Your propane supplier
mixes an odorant with the propane to make its
presence detectable. In some instances, the
odorant can fade, and the gas may no longer
have an odor. Before startup (and periodically
thereafter), have the propane supplier verify the
correct odorant level in the gas.
WARNING
Eliminate all system leaks. Continual fresh
make-up water will reduce heater life. Minerals
can build up in the heat exchanger, reducing
heat transfer, overheating heat exchanger, and
causing heat exchanger failure.
CAUTION
It is important that you purge the system of air
to avoid damage to the heater.