this is the 2nd thermostat to fail in 3 years time its a digital Honeywell
ct8775a. I live in Florida and it fails in the summer time while on cooling.
the thermostat will register the 80 degree setpoint and turn on but not shut
off ( thermostat always read house temp at 80) the house was 74 degrees last
night, replaced the thermostat and all seems fine. I don't know why these
would fail in the same way, should I go with a normal honey well thermostat?
(non digital).
thanks in advance
jeff

"Dig" wrote in message

I don't know why these would fail in the same way, should I go with a
normal honey well thermostat?
(non digital).

Were both failures or the same model? Maybe a bad design, or both made with
components from the same batch. Certainly, I would not BUY another one of
those, unless you get it under warranty.

If you must have an electronic one - maybe Consumer Reports has some
ratings. Else get a simply mechanical one - they last forever.

RichK

Dig wrote:

this is the 2nd thermostat to fail in 3 years time its a digital Honeywell
ct8775a. I live in Florida and it fails in the summer time while on cooling.
the thermostat will register the 80 degree setpoint and turn on but not shut
off ( thermostat always read house temp at 80) the house was 74 degrees last
night, replaced the thermostat and all seems fine. I don't know why these
would fail in the same way, should I go with a normal honey well thermostat?
(non digital).
thanks in advance
jeff


FWIW, I've had a digital Honeywell (albeit not that model -- mine is a
CT3400) for a lot longer than three years, and it has performed
flawlessly.

I notice your model is powered from the 24VAC control voltage. You
might try one that is battery powered -- perhaps your area has a lot of
lightning-related power transients, and they are causing unreliability.
You might also check that your control transformer is actually providing
a voltage that is within the specs required by the thermostat.

--
The e-mail address in our reply-to line is reversed in an attempt to
minimize spam. Our true address is of the form .

Dig wrote:

this is the 2nd thermostat to fail in 3 years time its a digital Honeywell
ct8775a. I live in Florida and it fails in the summer time while on cooling.
the thermostat will register the 80 degree setpoint and turn on but not shut
off ( thermostat always read house temp at 80) the house was 74 degrees last
night, replaced the thermostat and all seems fine. I don't know why these
would fail in the same way, should I go with a normal honey well thermostat?
(non digital).
thanks in advance
jeff


BTW, according to the manual I found on line, the CT8775A is a "heat
only" model, so I assumed you actually have a CT8775C.

--
The e-mail address in our reply-to line is reversed in an attempt to
minimize spam. Our true address is of the form .

thanks for your help CJT,
sorry about the thermostat # it actually is CT8775A,C. I have regular
maintenance performed by the Company that installed the unit and he said the
LV transformer was ok, and yes living in Florida we have a lot of lightning
spikes so may be that did it in.
thanks again,
jeff


"CJT" wrote in message
...
Dig wrote:

this is the 2nd thermostat to fail in 3 years time its a digital
Honeywell ct8775a. I live in Florida and it fails in the summer time
while on cooling. the thermostat will register the 80 degree setpoint and
turn on but not shut off ( thermostat always read house temp at 80) the
house was 74 degrees last night, replaced the thermostat and all seems
fine. I don't know why these would fail in the same way, should I go with
a normal honey well thermostat? (non digital).
thanks in advance
jeff
BTW, according to the manual I found on line, the CT8775A is a "heat only"
model, so I assumed you actually have a CT8775C.

--
The e-mail address in our reply-to line is reversed in an attempt to
minimize spam. Our true address is of the form .

On Sat, 28 Jul 2007 19:47:52 -0400, "Dig" wrote:

thanks for your help CJT,
sorry about the thermostat # it actually is CT8775A,C. I have regular
maintenance performed by the Company that installed the unit and he said the
LV transformer was ok, and yes living in Florida we have a lot of lightning
spikes so may be that did it in.

When I tried to inquire about a lightning rod for my house, everyone
on the phone assumed I was in Florida.

Surely with the whole rest of the country also having lightning too,
that was an unwarranted assumption.


Actually, I wanted to know if I could convert my metal fireplace and
metal chimney into a lightning rod. I thought this might be real
easy, but like I say, they all thought I was in Florida, and no one
could answer my question, 23 years ago.


thanks again,
jeff

"Dig" wrote in message
. ..
this is the 2nd thermostat to fail in 3 years time its a digital Honeywell
ct8775a. I live in Florida and it fails in the summer time while on
cooling.
the thermostat will register the 80 degree setpoint and turn on but not
shut
off ( thermostat always read house temp at 80) the house was 74 degrees
last
night, replaced the thermostat and all seems fine. I don't know why these
would fail in the same way, should I go with a normal honey well
thermostat?
(non digital).
thanks in advance
jeff


What's the model number?
Are you using the exact same model each time?

"RichK" wrote in message
. ..


Else get a simply mechanical one - they last forever.


Then why is it, that I've come across faulty ones? g

On Sat, 28 Jul 2007 22:50:24 -0500, kjpro @ usenet.com wrote:


"RichK" wrote in message
...


Else get a simply mechanical one - they last forever.


Then why is it, that I've come across faulty ones? g

That's probably just you.

On Jul 28, 4:50 pm, "Dig" wrote:
this is the 2nd thermostat to fail in 3 years time its a digital Honeywell
ct8775a. I live in Florida and it fails in the summer time while on cooling.
the thermostat will register the 80 degree setpoint and turn on but not shut
off ( thermostat always read house temp at 80) the house was 74 degrees last
night, replaced the thermostat and all seems fine. I don't know why these
would fail in the same way, should I go with a normal honey well thermostat?
(non digital).
thanks in advance
jeff

Isn't Florida the lightning capital of the US? If you
experience a lot of lightning or power surges in your
area the resulting voltage spikes could be damaging
your thermostat. I would start by measuring the AC
voltage feeding the thermostat because sometimes
the control transformer could be defective, improperly
installed or have the wrong tap from the primary winding
hooked up. Many of the control transformers installed
in HVAC units have a 208 or 240 volt primary winding
selection and if the wrong wire is connected, the voltage
from the secondary winding which is supposed to be 24
volts will be too high or too low. If your thermostat is
properly installed, there should be 24 volts AC between
the red and blue wires. If you're problem is voltage spikes,
you can install a surge arrester on your HVAC unit.

[8~{} Uncle Monster

"mm" wrote in message
...
On Sat, 28 Jul 2007 22:50:24 -0500, kjpro @ usenet.com wrote:


"RichK" wrote in message
...


Else get a simply mechanical one - they last forever.


Then why is it, that I've come across faulty ones? g

That's probably just you.


Yeah, like I'm the only tech that's finding them... rolleyes

On Jul 29, 12:37 am, wrote:
On Jul 28, 4:50 pm, "Dig" wrote:

this is the 2nd thermostat to fail in 3 years time its a digital Honeywell
ct8775a. I live in Florida and it fails in the summer time while on cooling.
the thermostat will register the 80 degree setpoint and turn on but not shut
off ( thermostat always read house temp at 80) the house was 74 degrees last
night, replaced the thermostat and all seems fine. I don't know why these
would fail in the same way, should I go with a normal honey well thermostat?
(non digital).
thanks in advance
jeff

Isn't Florida the lightning capital of the US? If you
experience a lot of lightning or power surges in your
area the resulting voltage spikes could be damaging
your thermostat. I would start by measuring the AC
voltage feeding the thermostat because sometimes
the control transformer could be defective, improperly
installed or have the wrong tap from the primary winding
hooked up. Many of the control transformers installed
in HVAC units have a 208 or 240 volt primary winding
selection and if the wrong wire is connected, the voltage
from the secondary winding which is supposed to be 24
volts will be too high or too low. If your thermostat is
properly installed, there should be 24 volts AC between
the red and blue wires. If you're problem is voltage spikes,
you can install a surge arrester on your HVAC unit.

[8~{} Uncle Monster


A lot of critical info is missing. Like were all 3 the same model?
I don't see how 3 different thermostats from diff manufacturers could
all fail in the exact same way (goes on showing 80 and never chgs or
turns off) from surges. If they are all the same, or at least
similar ones from same company, then it sounds more like a weak point
in the design.