"Jack Benimble" wrote in message
...
I have a 2-wire, 24v, single-stage heat only, SlantFin hot water
boiler, about 20 or 30 years old, maybe more. Two wires go from the
system to the thermostat in my living room. One wire is red and one
is white. On my current thermostat, the red wire connects to Rh and
the white wire connects to W1.

I bought a new programmable thermostat. It wants me to connect the
red wire to RH and the white wire to W2 (there is no W1), but also
calls for a common wire, which I don't have.

Installed with just the 2 wires, the thermostat keeps making a
clicking or chattering sound when the heat comes on. The sound
diminishes over time, but not completely. In the first minute or so,
it goes from loud clicking to a soft chattering sound that is much
lower in volume.

I didn't let it run long this way because I wasn't sure if it would
ruin the thermostat.

My question is, is there a way I can stop the chattering without a
common wire, since I don't have one? Also, if left with the clicking,
is that something which can damage the thermostat and/or other parts
of the heating system?

I am not versed in boiler transformers and such, so I am not sure how
to find a common "terminal" on my boiler to run a wire from. Is there
an alternate way to make this work without a common wire, or do I
absolutely need one? I don't even know if my boiler has a terminal
for a common wire.

If I follow the wires backwards from the current thermostat to my
boiler, the wires go into the basement to a Honeywell Aquastat valve
first, and from there into a big metal box with a removable cover
inside the boiler itself, behind the front boiler cover.

Can anyone offer me some advice? If needed, I can take some pictures
of the components in question and post them here or to a binary group,
or to an image hosting site.

I really love this new thermostat I bought. It is a Totaline touch
screen with password protected settings. I bought it because I pay
the heating bill but have a couple of boarders living in my house who
refuse to help me save on the heat bill. I want to use this to keep
them from altering my heat settings. I really don't want to return
the thermostat if at all possible. I want to keep and use it if I can
figure out this "common wire" problem.

I should also mention that on my current thermostat, there is a wire
which jumpers from the Rh terminal to the Rc terminal.

Is there a way I can jumper two different terminals on the thermostat
to get the desired effect, or no? Or is there some other alternate
way to get the chattering to stop without using a common wire?

The wiring diagram for my new thermostat can be found at
http://www.totaltouch.info/documents/TT_wiring.pdf - it also gives
information on each terminal and what it is for.

Could my solution be to run the white wire to the C terminal instead
of the W2 terminal, or would that create a huge problem? Like I said,
I know nothing about this stuff. I just wanted to replace my
thermostat.

Any advice or suggestions would be very helpful.

Thanks,

Jack



Real simple...you wont get it to work WITHOUT a common.
What you have now, is nothing but a loop from the transformer to the stat,
and then to the gas valve.
You have to have a C line or it wont work....period. Pull a 18-3 wire and be
done with it...