"flyer" wrote in message ...
"TURTLE" wrote in message
...
"Barb" wrote in message
om...
We have a house built in the 70's with a Nutone intercom system.
The the intercom worked well (built-in base unit in kitchen, with
4 other units throught the house), UNTIL we replaced our forced-air
electric furnace with a NEW gas furnace and new Honeywell
thermostat.
Now, you can hear the voices faintly through the intercom, but
you have to turn-up the volume and there is a lot of static noise.
I realize that the thermostat and the intercom might share the
same wiring. Is it coincidence that our intercom doesn't work
when we got the new furnace?
What can I do to fix the intercom?
Thanks
Barb
This is Turtle.
The newer gas furnaces use the Ground wire for the grounding the 24 volt
control
voltage. Yes I said Ground wire and not Common wire of the 115 volt
service. The
All Electric 220 volt service electrice furnace or called Air handler did
not
use the Ground wire of any 115 volt service. They had to get to a 115 volt
service in your house and then the gas furnace and intercom are in some
way
common to each other now.
I can't see it from here but I would say get the Intercom 115 volt service
and
the 115 volt service for the gas furnace seperated on different circuits.
The
only thing I can be seeing here as to the problem is either your not
Grounding
the furnace and intercom at all or they are common together on the same
circuit.
The only way for a gas furnace to effect the intercom would be it is
common in
some way to both electrically. Both using the same power source 115 volt
service
, common wires, and ground wires. I don't know about intercom systems but
I
would think they would have to have 115 volt service to make them run and
that
service is in some way common to the furnace power supply, ground wire ,
or
common wire.
Gas furnaces now days will use the ground wire to discharge any built up
power /
static power from the relay boards / computor boards of the furnace.
Now here is a wild one that I have seen happen when Gas furnaces start
messing
with other circuits in the home. The Ground wire outside at the meter pan
was
not grounding properly. Check the wire as to being hooked up and if some
dig
around the ground rod down about 6 inches and fill it with water and keep
it
fill for about 5 minutes and then try the intercom to working right. It is
works
right , you have a ground rod grounding problem.
Now you got me going out on a limb suggesting things here without me
seeing it.
TURTLE
Turtle, thanks for the info. We also have a 70's era Nutone intercom that I
would like to decommision and tear out of the walls. Am I looking at messing
up my 1-year new HVAC system if I start tearing out the intercom? How much
of that 115 volt supply is there? I thought it was all a low voltage
circuit. I'd appreciate any of your thoughts.
This is turtle.
I don't see any problem with ripping out the intercom you have and all the wire
with it but just don't rip any of the hvac system wires with it. They should be
totally seperate from the hvac system and the intercom system.
If you like E-Mail me and discuss it farther if you like or post here.
TURTLE
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