46
en
No.
Fault symptom
Possible cause
Explanation - Solution
16 The room tempera-
ture rises during DHW
operation.
3-way valve failure
Check the 3-way valve.
17 Water discharges
from pressure relief
valve.
(Primary circuit)
1. If continual – pressure relief valve may be
damaged.
1. Turn the handle on the pressure relief valve to check for foreign objects in it. If the
problem is not still solved, replace the pressure relief valve with a new one.
2. If intermittent – expansion vessel charge may
have reduced/bladder perished.
2. Check pressure in expansion vessel.
Recharge to 1 bar if necessary.
If bladder perished replace expansion vessel with a new one.
18 Water discharges
from pressure relief
valve (field supplied
item).
(Sanitary circuit)
1.
If continual – field supplied pressure reducing
valve not working.
1. Check function of pressure reducing valve and replace if necessary.
2. If continual – pressure relief valve seat may
be damaged.
2. Turn the handle on the pressure relief valve to check for foreign objects inside. If
the problem is not still solved, replace the pressure relief valve.
3. If intermittent – expansion vessel charge may
have reduced/bladder perished.
3. Check gas-side pressure in expansion vessel.
Recharge to correct precharge pressure if necessary.
If bladder perished replace expansion vessel with a new one with appropriate pre-
charge.
4.
DHW tank may have subjected to backflow.
4. Check gas-side pressure in DHW tank. If pressure in DHW tank is similar to that in
incoming mains, cold water supply that merges with incoming mains water supply
could flow back to DHW tank. Investigate source of back-feed and rectify error in
pipework/fitting configuration. Adjust pressure in cold supply.
19 Noisy water circula-
tion pump
Air in water circulation pump.
Use manual and automatic air vents to remove air from system.
Top up water if necessary to achieve 1 bar on primary circuit.
20 Noise during hot
water draw off
typically worse in the
morning.
1. Loose airing cupboard pipework.
1. Install extra pipe fastening clips.
2.
Heaters switching on/off.
2. Normal operation no action necessary.
21 Mechanical noise
heard coming from
the system.
1.
Heaters switching on/off.
Normal operation no action necessary.
2. 3-way valve changing position between DHW
and heating mode.
22 Water circulation
pump runs for a
short time unexpect-
edly .
Water circulation pump jam prevention mecha-
nism (routine) to inhibit the build-up of scale.
Normal operation no action necessary.
23 Milky/Cloudy water
(Sanitary circuit)
Oxygenated water
Water from any pressurised system will release oxygen bubbles when water is run-
ning. The bubbles will settle out.
24 Heating mode has
been on standby for
a long time (does
not start operation
smoothly.)
The time of “Delay” set in “Economy settings
for pump” is too short. (Go to “Service menu”
→ “Auxiliary settings” → “Economy settings for
pump”)
Increase the time of “Delay” in “Economy settings for pump” .
25 The FTC unit that was
running in the heating
mode before power
failure is running in
the DHW mode after
power recovery.
The FTC unit is designed to run in an operation
mode with a higher priority (i.e. DHW mode in this
case) at power recovery.
• Normal operation.
• After the DHW max. operation time has elapsed or the DHW max. temperature has
been reached, the DHW mode switches to the other mode (ex. Heating mode).
26 Cooling mode is NOT
available.
Dip SW2-4 is OFF.
Turn Dip SW2-4 to ON. (Refer to “5.1 Dip Switch Functions” in this manual.)
27 The cooling system
does not cool down to
the set temperature.
1. When the water in the circulation circuit is un-
duly hot, Cooling mode starts with a delay for
the protection of the outdoor unit.
1.
Normal operation.
2. When the outdoor temperature is lower than
the preset temperature below which the
freeze stat. function is activated, Cooling
mode does not start running.
2.
To run Cooling mode overriding the freeze stat. function, adjust the preset tem-
perature below which the freeze stat. function is activated. (Refer to “Freeze stat
function” on Page 38.
28 The electric heaters
are activated shortly
after DHW or LP
mode starts running
after Cooling mode.
The setting time period of Heat-pump-only
operation is short.
Adjust the setting time period of Heat-pump only operation. (Refer to “Electric heater
(DHW)“ in the table of <Auxiliary settings> on Page 19.)
29 During DHW or LP
mode following the
cooling mode, error
L6 (circulation water
freeze protection)
occurs and operation
stops frequently.
If the preset temperature below which the freeze
stat. function is activated is low, error L6 is more
likely to occur interruption operation before the
freeze stat. function is activated.
Adjust the preset temperature below which the freeze stat. function is activated. (Refer
to “Freeze stat function” on Page 38.)
30 Heat pump is forced
to turn ON and OFF.
Smart grid ready input (IN11 and IN12) is used, and
switch-on and off commands are input.
Normal operation no action necessary.
8. Troubleshooting
Summary of Contents for PAC-SIF051B-E
Page 62: ......
