I have 3 Sears digital thermostats in my house all top rated by
Consumer Reports many years ago. Don't know who makes them. They all
have a slight click. I am very adverse to noise but they are not loud
enuf to be annoying.


"George E. Cawthon" wrote in message
...
You are right, there was no click with my digital Honeywell
thermostat. Can't really imagine there would be one with
any kind of electronic thermostat, wouldn't they all use a
solid state switch. Why would anyone put the mechanical
relay, if there is one, in the thermostat instead of at the
furnace. There may be a click at my furnace but there is so
much other noise when it start that you couldn't hear a
click without having the furnace cover off. A mechanical
relay in a digital thermostat sounds like a real design
flaw.

"Bob M." wrote:

There are a few that use solid-state components to activate the
HVAC
equipment, and these may be described as having battery backup,
but running
on the voltage provided by the HVAC equipment. But most of the
units are
more universal in their design, so they work on the majority of
control
systems used on HVAC equipment.

Unfortunately, the best and most universal way to activate the
HVAC
equipment is with dry contacts, the kind that small relays have.
Being an
electro-mechanical device, when the contacts activate, there is
some noise
associated with that action. Some are noisier than others. The
relays are
small, the contacts are small, so to make a good connection they
must really
"snap" into position.

After a while, either you get used to it, or you move the
thermostat around
the corner to a room or space where you can't hear it anymore, and
hope that
the resulting temperature is still within your comfort zone.

The original Honeywell round thermostats use a mercury switch
inside that's
totally silent as it makes the connection, but this kind of unit
is not
digital and can't be programmed. I would not be surprised however
to find
that the Honeywell units are very quiet, if not silent, so it may
be worth
buying one and trying it out. If there's no improvement, or it's
too noisy,
you should be able to return it to the store where you purchased
it.

Bob M.
======
"Dave Gallant" wrote in message
om...
Greetings:

I have a Hunter Digital Thermostat [Set and Save 110], and the
relay
makes a "click" noise every time the unit calls for heat. Their
help
department tells me that this is a normal function of this unit.

Is this a standard operation of all digital thermostats? If not,
I
will be making a change. I have an office setup within 15 feet
of the
unit, and the sound can distracting. Suggestions on a good
replacement
would be appreciated - heat only, for hot water baseboards.

Thanks,

Dave