42
UltraTemp
®
Heat Pump Installation and User’s Guide
Problem or Symptoms
Possible Cause
Corrective Action
Higher than Normal Head Pressure, lower
than normal suction pressure with high
superheat and very cold or frosty distribu-
tor tubes, may have no Alarm
TXV stuck closed.
1. Disconnect TXV bulb from suction line (SL), have it in your
hand, if pressures go back to normal, then reinstall the bulb
on suction line (it may have some debris stuck in the port).
For adjustable TXVs open adjustable valve, it may remove
the debris and set it back to original position. 2. If (1) does
not work, recover the charge, remove bulb from SL, unscrew
TXV head, shake it, if rattles, replace head (PN KT-45-ZGA),
if not, replace TXV and fi lter dryer and charge appropriately.
Lower than Normal Head Pressure,
higher than normal suction pressure with
cold suction line and compressor and no
superheat, may have no Alarm.
TXV stuck open.
1. Check to see if TXV bulb is fi rmly attached
to suction line, if loose, attach fi rmly by tighten
ing the clamp over the bulb and suction line.
2. If (1) above does not work, reclaim charge and replace
TXV and fi lter dryer with nameplate charge.
Unusually higher than normal current.
TXV stuck closed/partially closed, insuffi cient
water fl ow, system overcharged.
See Possible Cause column for: TXV stuck closed, Insuf-
fi cient water fl ow, and Unit overcharged.
Low current with high superheat.
Unit undercharged.
Find source of refrigerant leak and fi x. Pull vacuum and
charge.
Unit runs, but trips continuously.
Wires not connected properly.
Fix the miswire as per the Wiring Diagrams.
*Temperature Resistance Chart
°F
OHMS
°F
OHMS
°F
OHMS
°F
OHMS
°F
OHMS
0
85,387
51
19,377
66
13,136
81
9,076
96
6,382
10
62,479
52
18,870
67
12,809
82
8,861
97
6,238
20
46,225
53
18,377
68
12,491
83
8,651
98
6,097
30
34,561
54
17,899
69
12,182
84
8,447
99
5,960
40
26,100
55
17,435
70
11,882
85
8,249
100
5,827
41
25,391
56
16,985
71
11,589
86
8,056
101
5,697
42
24,704
57
16,548
72
11,305
87
7,867
102
5,570
43
24,037
58
16,123
73
11,029
88
7,684
103
5,446
44
23,391
59
15,711
74
10,761
89
7,506
104
5,326
45
22,764
60
15,310
75
10,500
90
7,333
105
5,208
46
22,156
61
14,921
76
10,246
91
7,164
106
5,094
47
21,566
62
14,543
77
9,999
92
6,999
107
4,982
48
20,993
63
14,176
78
9,758
93
6,839
108
4,873
49
20,438
64
13,820
79
9,525
94
6,683
110
4,664
50
19,900
65
13,473
80
9,297
95
6,530
120
3,758
Problems and Corrective Action (3 Phase Units Only)
Problem or Symptoms
Possible Cause
Corrective Action
Unable to turn Heat Pump ON. Display is
Blank. Unit will NOT start.
Incorrect Wiring.
Check the Light on Phase Monitor inside the electrical box.
If red, switch two of the Input wires. Any two of the three can
be switched.
Faulty Phase Monitor.
Call dealer or factory for advice before attempting to replace
parts. Replace Phase Monitor.
Loose wire on Phase Monitor, either from the
supply input power or the output side.
Check the Light on Phase Monitor inside the electrical box.
If the Light is Red, fi x the supply power loose end. If the
Light is Green, fi x the output loose wire.
Compressor making a loud or unusual
noise or sounds during operation. Fan is
turning, no cool air discharge out of top of
heater. Unit ON, and Set Temperature is
above Actual, but Unit is not heating.
Compressor running Backwards. This usually
happens if the compressor wire harness is dis-
connected for possible repair or replacement.
Switch any two of the three wires on the compressor side of
the Contactor.