4-3
MAINTENANCE
SL 26-260 G3, SL 40-399 G3 MODULATING GAS BOILERS
4.1.13 Relief Valve - Maintenance and Testing
The relief valve manufacturer requires that under normal operating conditions a “try
lever test” must be performed every two months. Under severe service conditions, or if
corrosion and/or deposits are noticed within the valve body, testing must be performed
more often. A “try lever test” must also be performed at the end of any non-service period.
Test at or near the maximum operating pressure by holding the test lever fully open for at
least 5 seconds to flush the valve seat free of sediment and debris. Then release the lever
and permit the valve to snap shut.
If the lever does not activate, or there is no evidence of discharge, discontinue use of
equipment immediately and contact a licensed contractor or qualified service personnel.
If the relief valve does not completely seal, and fluid continues to leak from the discharge
pipe - perform the test again to try and flush any debris that may be lodged in the valve.
If repeated tries fail to stop the leakage, contact a licensed contractor or qualified service
personnel to replace the valve.
While performing a “try lever test”, a quantity of heat transfer fluid will be discharged from
the piping system and the system pressure will drop. This fluid must be replaced. It is
highly recommended that a system pressurization unit, such as an Axiom Industries model
MF200 be employed to refill and pressurize your system. Capture the discharged fluid
in a container and recycle it by returning it to the system feeder unit. This is particularly
important when your system contains treatment chemicals or glycol solutions. If the
system employs plain water, the boiler auto fill valve must be turned on in order to
recharge the lost fluid.
CAUTION
Installers should inquire of
local water purveyors as to the
suitability of their supply for use
in hydronic heating systems.
If water quality is questionable,
a local water treatment expert
must be consulted for testing,
assessment and, if required,
treatment.
Alternatively, water or hydronic
fluid of known quality can be
brought to the site.
CAUTION
Before testing the relief valve,
make certain the discharge pipe
is properly connected to the
valve outlet and arranged to
contain and safely dispose of
equipment discharge.
WARNING
Do not use automotive-type
ethylene or other types of
automotive glycol antifreeze,
or undiluted antifreeze of
any kind. This may result in
severe boiler damage. It is the
responsibility of the Installer to
ensure that glycol solutions are
formulated to inhibit corrosion
in hydronic heating systems
of mixed materials. Improper
mixtures and chemical additives
may cause damage to ferrous
and non-ferrous components
as well as non-metallic, wetted
components, normally found
in hydronic systems. Ethylene
glycol is toxic, and may be
prohibited for use by codes
applicable to your installation
location. For environmental
and toxicity reasons, IBC
recommends only using non-
toxic propylene glycol.
