Tstat wiring help
#1
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Tstat wiring help
I have a heat pump system. I am replacing a Robertshaw 9429 Tstat with a Venstar T1100 rec.
the robershaw wiring is
L-BLACK
R-RED
C-BLUE
Y-YELLOW
G-GREEN
W2-WHITE
E-WHITE JUMPER FROM W2
O-ORANGE
I have wired the Venstar
C-BLUE
R-RED
G-GREEEN
W1-O-B -ORANGE
Y1-YELLOW
W2-WHITE
THERE IS NOT A SLOT FOR THE BLACK WHICH GOES DIRECTLY TO THE HEAT PUMP SO I HAVE TAPED IT UP.
There is also no E slot on Venstar.
Wiring at the air handler is
C-BLUE
G-GREEN
R-RED
Y-YELLOW
O-ORANGE
W2-WHITE-
W1-BROWN WHICH GOES TO THE HEAT PUMP AND NOT THE THERMOSTAT.
The issue I am having is that when the air handler starts to kick on it blows the 5 amp fuse on the air handler board. Is this a lack of power issue or have I mis wired the venstar? the Robertshaw does not blow the fuse.
I would be grateful for anyhelp!
the robershaw wiring is
L-BLACK
R-RED
C-BLUE
Y-YELLOW
G-GREEN
W2-WHITE
E-WHITE JUMPER FROM W2
O-ORANGE
I have wired the Venstar
C-BLUE
R-RED
G-GREEEN
W1-O-B -ORANGE
Y1-YELLOW
W2-WHITE
THERE IS NOT A SLOT FOR THE BLACK WHICH GOES DIRECTLY TO THE HEAT PUMP SO I HAVE TAPED IT UP.
There is also no E slot on Venstar.
Wiring at the air handler is
C-BLUE
G-GREEN
R-RED
Y-YELLOW
O-ORANGE
W2-WHITE-
W1-BROWN WHICH GOES TO THE HEAT PUMP AND NOT THE THERMOSTAT.
The issue I am having is that when the air handler starts to kick on it blows the 5 amp fuse on the air handler board. Is this a lack of power issue or have I mis wired the venstar? the Robertshaw does not blow the fuse.
I would be grateful for anyhelp!
#2
Welcome to the forum!! Did you set the switches to HP for heat pump and to O for the reversing valve as shown on page 5 of your manual?
http://www.venstar.com/Support/Insta...nstallRev3.pdf
http://www.venstar.com/Support/Insta...nstallRev3.pdf
#4
I can't find any info on the Robertshaw 9429. Is that a complete/correct model number ?
Usually a fuse blowing can be traced to the Common in the wrong place or the wrong color used for common.
What's the make and model of the air handler ?
Usually a fuse blowing can be traced to the Common in the wrong place or the wrong color used for common.
What's the make and model of the air handler ?
#6
It appears you have the correct wiring based on your description. If you can post a clear photo of the wiring you have at the Venstar thermostat maybe someone can see something that may be causing your issues.
#7
Sw #7 ---> off for non electric first stage heat
Sw #8 ---> on for heat pump
Sw #9 ---> off for "O" reversing valve
These are the switch settings and you appear to have the wiring correct.
Sw #8 ---> on for heat pump
Sw #9 ---> off for "O" reversing valve
These are the switch settings and you appear to have the wiring correct.
#12
Ok, good deal. Just wanted to be sure. In your photo of the dip switches I noticed the switches do not match the configuration for a heat pump system as shown on page 5 in the manual. The only switch in the ON position is switch 8 (HP). I suggest setting those as shown in the manual and then see if your fuse still blows.
#13
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That is where I started out in the beginning and fuse still blew. The first 6 switches are just for setting the house code which I have set to 10. 7 off 8 on and 9 off.
#14
Here's what I would do now.
Remove thermostat and take a jumper wire and jump from .....
R ---> G
R ---> Y
R ---> W1/O
R ---> W2
Try one set at a time and don't touch the C terminal.

If the fuse doesn't blow.... it would appear you have a thermostat problem.
If the fuse does blow.... you need to determine which line has the short on it.
Remove thermostat and take a jumper wire and jump from .....
R ---> G
R ---> Y
R ---> W1/O
R ---> W2
Try one set at a time and don't touch the C terminal.

If the fuse doesn't blow.... it would appear you have a thermostat problem.
If the fuse does blow.... you need to determine which line has the short on it.