Operating instructions

Part number 550-141-887/0800
31
AHE Series 4 Direct Vent Wall-Mounted Boilers — Boiler Manual
continued
Check/test continued
Limit controls and cutoffs
1. Inspect and test the boiler limit control. Verify
operation by turning control set point below boiler
temperature. Boiler should cycle off. Return dial
to original setting.
2. Inspect and test additional limit controls or
temperature plug switch (see Figure 25) installed
on system. Make sure aluminum foil on boiler
insulation does not come in contact with
temperature plug switch terminals, preventing
boiler operation.
Expansion tank
Expansion tanks provide space for water to move in and
out as the heating system water expands due to
temperature increase or contracts as the water cools.
1. AHE boilers require a diaphragm-type expansion
tank with at least one automatic air vent. See Figure
12 on page 15 for suggested best location of the
expansion tank.
2. If relief valve has tended to weep frequently, the
expansion tank may be waterlogged or undersized.
Check the following:
a. Check tank size to be sure it is large enough
for the system.
b. If size is too small, add additional tank(s) as
necessary to provide sufficient expansion.
c. If tank size is large enough, remove tank from
system and check charge pressure (usually 12
psig for residential applications). If tank won’t
hold pressure, membrane has been damaged.
Replace tank.
Boiler relief valve
1. See Figure 26. Inspect the relief valve and lift the lever to verify flow as
in the following warnings, excerpted from a relief valve manufacturer’s
warning label. Before operating any relief valve, ensure that it is piped
with its discharge in a safe area to avoid severe scald potential. Read
Manual Section 4a on page 15 before proceeding further.
Safety relief valves should be reinspected at least
once every three years
, by a licensed plumbing
contractor or authorized inspection agency, to ensure
that the product has not been affected by corrosive water
conditions and to ensure that the valve and discharge
line have not been altered or tampered with illegally.
Certain naturally occurring conditions may corrode the
valve or its components over tine, rendering the valve
inoperative. Such conditions are not detectable unless
the valve and its components are physically removed
and inspected. This inspection must only be conducted
by a plumbing contractor or authorized inspection
agency — not by the owner. Failure to reinspect the
boiler relief valve as directed could result in unsafe
pressure buildup, which can result in severe personal
injury, death or substantial property damage.
Following installation, the valve lever must be
operated at least once a year
to ensure that waterways
are clear. Certain naturally occurring mineral deposits
may adhere to the valve, rendering it inoperative. When
manually operating the lever, water will discharge and
precautions must be taken to avoid contact with hot
water and to avoid water damage. Before operating lever,
check to see that a discharge line is connected to this
valve directing the flow of hot water from the valve to a
proper place of disposal, otherwise severe personal
injury may result. If no water flows, valve is inoperative.
Shut down boiler until a new relief valve has been
installed.
2. After following the above warning directions, if the relief valve weeps
or will not seat properly, replace the relief valve. Ensure that the reason
for relief valve weeping is the valve a not over-pressurization of the
system due to expansion tank waterlogging or undersizing.
Review
1. Review the “User’s Information Manual” with the owner.
2. Emphasize the need to perform the maintenance schedule specified in
the “User’s Information Manual” (and this manual as well).
3. Remind the owner of the need to call in a licensed contractor should
the boiler or system exhibit any unusual behavior.
4. Remind the owner to follow the proper shutdown procedure and to
schedule an annual start-up at the beginning of the next heating season.
Figure 26
Relief valve, typical
88736
Figure 25
Temperature plug switch
88719