72
PHTM II
Combi Installation, Operating & Service Instructions
110331-07 - 8/23
18
Service and Maintenance
(continued)
E. Refer to Sections 7 thru 9 to re-assemble
any vent system components that are
disassembled during this inspection and for
details on supporting, pitching and
terminating vent system.
12.
Inspect hydronic system and DHW piping.
A. Look for leaks and repair if found. If system
contains antifreeze, or other additives, test
and/or maintain them as directed by additive
manufacturer.
B. Test heating system and DHW inlet water
quality to ensure they meet minimum
requirements specified in Section 15 Start-Up
and Checkout and Section 11 Domestic Water
Piping.
C. Inspect DHW flow limiter. Clean any debris/
build up, replace if necessary.
D. If DHW cold water supply is equipped with
a water filter replace according to
manufacturer's recommendations.
E. Refer to Appendix B for important information
on quality and boiler additives.
13.
Flush plate heat exchanger.
Back-flush (against normal flow) DHW loop to
remove scaling. Vinegar can be used to help
remove deposits.
14.
Inspect safety relief valve.
WARNING
Explosion Hazard.
Safety relief valves require periodic
maintenance. Refer to relief valve
manufacturer's instructions for frequency and
proper procedure. Any testing or maintenance
shall be done by a qualified installer, service
agency or gas supplier.
15.
Place boiler back into operation.
A. Replace any wiring which has been
disconnected.
B. Perform visual inspection of gas piping
to ensure no inadvertent damage to gas train
components during servicing.
C. Follow all instructions in Section 15 Start-Up
and Checkout to place boiler back in service,
including performance of combustion test.
16.
Test boiler flow switch.
A. Start with boiler in standby.
B. Either close a shut off in boiler loop or unplug
boiler pump at connecter.
C. Initiate a call for heat and confirm that boiler
shows an Active Fault (
H05
) indicating flow
switch is open.
WARNING
Component Damage.
If burner comes on with no flow through boiler,
there is a problem with flow switch. Turn boiler
off immediately. Failure to do so could result in
severe heat exchanger damage.
17.
Assure that all safety and operating controls
and components are operating properly before
placing boiler back in service
.
!
!
