Ref
Checklist
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Maintenance
Only to be carried out by trained and qualified operatives.
Remarks /Notes
1
Turn off the District side Isolation valves and isolate the HIU electrical supply
(Fig 4, Section Installation).
Drain the Primary side of the HIU. (Fig 6 , Section: Installation)
If leaving the installation while maintenance is in progress notices should be
placed accordingly to prevent others from interfering with equipment and valves.
2
Inspect STRAINER on the HIU Primary (District) side flow. (Fig 1 and 2)
-
REMOVE
CAP, REMOVE MESH, CLEAN AND REPLACE.
Sample the Primary water chemical composition and check against specification.
Report any abnormalities to the Building manager immediately.
3
ISOLATE all connections to HIU (central heating flow and return and cold water
mains connection and DHW outlet). DRAIN the HIU using the built in drain valves
4
Check all strainers, including filters fitted on the cold water mains supply .
This may also include Pressure Reducing Valves with integral strainer cartridges.
Always isolate any components before maintenance.
5
If a potable vessel is fitted on the cold water main before the HIU the pressure
should be checked. Pressure charge value will be seen on the vessels data label.
Check if a Safety valve has been installed in the cold main, and check operation by
twisting the cap and check the valve re
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seats without leaking. Grit may get caught
on the seal, remove by flushing (twist the cap on the safety valve)
6
Central Heating side of the HIU
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check the safety valve discharges by twisting the
cap. Check the safety valve re
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seats and seals.
7
Central Heating side of the HIU
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check the expansion vessel pressure and adjust
or recharge to 0.75 bar.
8
PLATE HEAT EXCHANGERS
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MAINTENANCE
Special attention should be given to the plate heat exchangers, recent reported
loss of performance may be caused by dirty or blocked plates (lime scale).
Heating PHE (Fig 8A)
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remove the 4 fixing screws.
DHW PHE (Fig 8B) remove the 4 fixing screws.
Read Zilmet Plate Heat Exchanger Maintenance Recommendations on next page.
After cleaning (or replacing) refit both plate heat exchangers. Tighten the 4 fixing
bolts each PHE until sealed with reasonable force
-
do not over
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tighten.
9
PICV Settings
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these are set at the factory and should not be tampered with. This
setting is critical to the HIU performance design. The setting can be checked by
removing the PICV Actuator (by hand, avoid damaging the securing nut).
To replace the actuator the pin needs to be fully retracted.
The method for this is only for fully trained operatives.
10
Check all drain valves are closed, open isolation valves and REFILL (secondary and
primary), check for leaks and vent air from the systems.
Central Heating side of the HIU
-
check the safety valve discharges by twisting the
cap. Check the safety valve re
-
seats and seals.
Satisfied all is checked, replace casing and carry out commissioning check list.
SECTION 8
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Maintenance instructions
09/17 E & OE
System maintenance, commissioning and design is not the responsibility of INTA.
Summary of Contents for Hiper Xi45 INDIRECT HIU 45DHW/10HTG
Page 28: ...09 17 E OE ...
