Weil-McLain 550-110-260/02002 Boiler Manual, Boiler relief valve, lever must be operated AT LEAST

Boiler Manual

❏Check/test . . . . . . . discharge line have not been altered or tampered with illegally. Certain naturally occurring conditions may

	corrode the valve or its components over time,
circulation of air-saturated tank water back to	rendering the valve inoperative. Such conditions are
the system and prevents the air from bubbling	not detectable unless the valve and its components are
up through the water as it returns from the	physically removed and inspected. This inspection must
system.	only be conducted by a plumbing contractor or
• Do not use automatic air vents in systems	authorized inspection agency — not by the owner.
with closed-type tanks. The air will escape	Failure to reinspect the boiler relief valve as directed
from the system instead of returning to the	could result in unsafe pressure buildup, which can
tank. Eventually, the tank will waterlog and no	result in severe personal injury, death or substantial
longer control pressurization. The boiler relief	property damage.
valve will weep frequently.		Following installation, the valve
Diaphragm- or bladder-type — welded gas tight
		lever must be operated AT LEAST
with a rubber membrane to separate the tank
	ONCE A YEAR to ensure that waterways are clear.
pressurizing air and the water. May be located at
	Certain naturally occurring mineral deposits may
any point in the system, but most often found near
	adhere to the valve, rendering it inoperative. When
the boiler.
	manually operating the lever, water will discharge and
• Systems with this type of expansion tank
	precautions must be taken to avoid contact with hot
require at least one automatic air vent,
	water and to avoid water damage. Before operating
preferably located on top of an air eliminator,
	lever, check to see that a discharge line is connected to
as shown in examples in manual section 3.
	this valve directing the flow of hot water from the valve
2. If relief valve has tended to weep frequently, the
	to a proper place of disposal otherwise severe personal
expansion tank may be waterlogged or undersized.	injury may result. If no water flows, valve is inoperative.
Closed-type tank — tank is most likely	Shut down boiler until a new relief valve has been
	installed.
waterlogged. Install a tank fitting if not already
installed. Then check fill level per fitting	2. After following the above warning directions, if the
manufacturer’s instructions. If fill level is correct,	relief valve weeps or will not seat properly, replace
check tank size against manufacturer’s instructions.	the relief valve. Ensure that the reason for relief valve
Replace with a larger tank if necessary.	weeping is the valve and not over-pressurization
Diaphragm- or bladder-type — first, check tank	of the system due to expansion tank waterlogging
	or undersizing.
size to be sure it is large enough for the system. If
size is too small, add additional tank(s) as necessary
to provide sufficient expansion. If tank size is large
enough, remove tank from system and check charge
	Figure 23 Relief valve, typical
pressure (usually 12 psig for residential
applications). If tank won’t hold pressure,
membrane has been damaged. Replace tank.

Boiler relief valve

1.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 3a 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

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Part number 550-110-260/0200	39