"Pete C." wrote in message
...
Robert11 wrote:

Hello,

Have a gas fired, hot air furnace.

Last year they put in on of these really fancy, 7 day programmable
Honeywell
thermostats for it.
Works fine.

Every month or so, I replace the filter.

The thermostat has just come up with a message to change the filter.

Am I correcdt that this message is based purely on time elapsed, and that
I
never "reset" it at the
time I changed the filter (don't know how to) ?

In other words, it really does Not monitor the filter's condition at all,
just elapsed time ?

Right ?

Thanks,
B.

Not elapsed time, like every 3 months, but elapsed fan run time so a
more accurate reflection of the filters expected condition. You'll get a
longer interval during the "off" seasons with minimal heating and
cooling. You might even be able to adjust the time setpoint to better
match the filters you are using and dust conditions. One feature I'd
like to see is a minimum fan run time function to insure the fan cycles
for air filtering purposes even if heating or cooling is not required.

If you have that type of thermostat, you can do that. Just set your fan
setting to CIRC. The fan runs at random intervals about 35% of the time.