4-3
MAINTENANCE
SFC BOILER / WATER HEATERS - SFC 199
Antifreeze concentration must be between 25% and 35% of the total volume of
water in the system.
4.1.12 System Treatment
•
Check consistency of any system treatment used, for appropriate mixture.
Chemical inhibitors are consumed over time, lowering their density.
•
Verify proper operation after servicing.
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, you must test
more often. Also perform a “try lever test” at the end of any non-service period.
Test at or near 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 attempts 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. IBC highly recommends using a system pressurization unit such
as an
Axiom Industries model MF200
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, turn on the unit’s
auto fill valve to recharge the lost fluid.
4.1.14 Domestic Hot Water System
Quality of the domestic cold water is very important to the longevity of the unit.
The recommended pH of the domestic water is between 6.5 and 8.5. The internal
domestic water heat exchanger tubing and the flow sensor is subject to fouling if
exposed to hard water (over 7 grains of hardness) or has a TDS of 500mg/L or
higher.
See Table 13.
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.
NOTE
Installers should contact
local water purveyors about
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.
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 unit damage. The
installer is responsible
in ensuring 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.
