22
Part Number 550-142-320/0720
GWA
Series 3
Gas-Fired Water Boilers –
Boiler Manual
Fill the system with water
1. Close manual and automatic air vents and boiler drain cock.
2. Fill to correct system pressure. Correct pressure will vary
with each application. Typical cold water fill pressure for a
residential system is 12 psi.
3. Purge air from system:
a. Connect a hose to purge valve or valves, if installed.
Route hose to an area where water can drain and be
seen.
b. Close the boiler 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 makeup 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.
4. Open automatic air vent (diaphragm-type or bladder-type
expansion tank systems only) one turn.
5. Open other vents:
a. Starting on the lowest floor, open air vents one at a time
until water squirts out.
b. Repeat with remaining vents.
6. Refill to correct pressure.
Inspect system water piping
After filling the boiler and system with water, inspect all piping
throughout the system for leaks. If found, repair immediately.
Repeat this inspection after the boiler has been started and
the system has heated up.
Leaks must be repaired at once. Failure to do so
can damage the boiler, resulting in substantial
property damage.
Do not use petroleum-based cleaning or sealing
compounds in boiler system. Severe damage to
boiler will occur, resulting in substantial property
damage.
Determine if water treatment is needed
Do not use petroleum-based cleaning or sealing
compounds in boiler system. Severe damage to
boiler will occur, resulting in substantial property
damage.
Eliminate all system leaks. Continual fresh makeup
water will reduce boiler life. Minerals can build up
in sections, reducing heat transfer, overheating
cast iron, and causing section failure.
Verify water chemistry
Consult local water treatment companies for unusually hard
water areas (above 7 grains hardness) or low pH water condi-
tions (below 7.0). Boiler water pH of 7.0 to 8.5 is recommended.
Freeze protection (when used)
Use antifreeze made especially for hydronic systems. Inhibited
propylene glycol is recommended.
Do not use ethylene glycol, automotive or undiluted
antifreeze. Severe personal injury or death can result.
1. Determine antifreeze quantity according to system water
content. Boiler water content is listed on page 51. Remem-
ber to include expansion tank water content.
2. Follow antifreeze manufacturer’s instructions.
3. A 50% solution of propylene glycol/water provides maxi-
mum protection to about -30 °F.
4. Local codes may require back flow preventer or actual
disconnect from city water supply.
5. When using antifreeze in a system with automatic fill, install
a water meter to monitor water makeup. Glycol will leak
before the water begins to leak, causing glycol level to drop.
Added water will dilute the antifreeze, reducing the freeze
protection level.
Check for gas leaks
Before starting the boiler, and during initial
operation, smell near the floor and around the
boiler for gas odorant or any unusual odor. Do not
proceed with start-up if there is any indication of
a gas leak. Repair any leak at once.
Propane boilers only — Your propane supplier
mixes an odorant with the propane to make its
presence detectable. In some instances, the odor-
ant can fade and the gas may no longer have an
odor.
• Propane gas can accumulate at floor level. Smell near
the floor for the gas odorant or any unusual odor. If
you suspect a leak, do not attempt to light the pilot.
• Use caution when attempting to light the propane
pilot. This should be done by a qualified service
technician, particularly if pilot outages are common.
• Periodically check the odorant level of your gas.
• Inspect boiler and system at least yearly to make
sure all gas piping is leak-tight.
• Consult your propane supplier regarding instal-
lation of a gas leak detector. There are some
products on the market intended for this purpose.
Your supplier
may be able to suggest an appropriate device.
7 Start-up
Preparation
Inspect base insulation
Check to make sure insulation is secure against all four sides of
the base. If insulation is damaged or displaced, do not operate
boiler. Replace or reposition insulation.
Failure to replace damaged insulation or reposition
insulation can result in a fire hazard, causing
severe personal injury, death or substantial
property damage.
The boiler contains ceramic fiber and fiberglass
materials. Use care when handling these materials
per instructions on page 52 of this manual. Failure
to comply could result in severe personal injury.
