SECTION 9: HEATING PLANT START-UP
17
STEP 1: PLANNING AHEAD
1. Check flow direction arrows imprinted on water system
components are pointing in the proper direction.
2. If system was not previously hydrotested, fill system.
Check all temperature/pressure indicators to assure there
is at least the desired cold fill pressure in the system.
3. Check all fittings and components for visible signs of
leakage, including each module's (and header's) supply
and return water connections.
4. Check that system pump(s) are interlocked with the
heating plant's operating controls so modules cannot fire
without pump(s) running.
NOTE:Do not draw water from heating system for
cleaning. Minerals in the water can build up on heat
transfer surface and cause overheating and subse-
quent failure of the cast iron sections.
1. Thoroughly purge system following standard purging
practices. Remember, every loop in the system must be
properly purged.
2. Check air elimination equipment for proper operation to
be certain there is no air in the water system.
3. With main gas valve OFF, turn on power to modules.
Open all zones individually; let system pump(s) run until
all air is purged from each zone (sound of air bubbles
flowing in piping has been eliminated).
4. Then operate system pump(s) with all zones open;
continue for the minimum time required to pass entire
system volume through separation point until sound of air
bubbles flowing in piping has been eliminated.
5. Open main gas valve, allowing gas to flow through gas
piping system. Open each burner's gas inlet.
6. Set operating control(s) to call for heat and follow start-
up instructions packaged with burners.
7. Allow system water temperature to rise slowly to about
30° F above fill temperature; shut down modules but
allow system pump(s) to run continuously. When all
sounds of air bubbles are eliminated, increase system
temperature another 30° F. Repeat procedure until maxi-
mum system design temperature is reached.
8. Start and stop burners several times by raising and
lowering the controls settings.
9. Check all safety and operating controls to be sure they
are operating in accordance with manufacturer's recom-
mendations.
a. Hi-Limit Aquastat: Mounted on each module, it cuts
off gas supply to the module when module wa-ter tem-
perature exceeds setting. Check high limit is set at 220°
F. To verify aquastat operation, with a small screwdriv-
er, reduce high limit setting to 100° F. Fire module until
water temperature reaches or exceeds 100° F, at which
time the burner should shut off. If for any reason burn-
er does not shut off, or allows the water temperature to
exceed 120° F, replace aquastat. If no replacement is
necessary, return setting to 220° F.
b. Manual Reset High Limit: Mounted in supply head-
er, it shuts off all module burners if system operating
water temperature exceeds setting. Check that setting
is 250° F. To verify operation, with a small screwdriver,
reduce setting while heating plant is firing. All module
burners should shut off, as operating water tempera-
ture exceeds the reduced setting. If module burners do
not shut off, check high limit electrical wiring. If O.K.,
replace high limit.
c. Check that low water cutoff(s) actually shut down
heating plant as intended.
10. Before leaving the job, make sure heating plant
installation has been inspected and approved by local
authorities having jurisdiction over the installation.
STEP 2: START-UP & ADJUSTMENTS
DANGER: To avoid fire or explosion hazards: Do not
store anything against modules or allow dirt or
debris to accumulate in area immediately surround-
ing modules. Keep heating plant area clear and free
from combustible materials, gasoline and other
flammable vapors and liquids. Lint, paper or rags
must not be allowed to accumulate near burners. Do
not place clothing on module casings to dry.
