I've installed and am running a Central Boiler outdoor wood boiler heating two buildings. I have two propane forced air furnaces as backup. My furnace guy installed two 2stage heat/ 1-cool honeywell FocusPro5000. Problem-There is not enough tempreture difference between first and second stage heat. If there's a 2degree difference between stat setpoint and room temp, both stages come on. I emailed honeywell and was told all factors that determined when second stage kicked in, and that the 2-3 degree temp difference could not be changed. I want a 2stage heat/ 1 cool stat that I can have more control of. A 5-10 degree temp difference would be nice. I have heard of other outdoor boiler users using two stats to control. One stat controlling the fan only(outdoor boiler) and the second(forced air propane) as back-up- at a much lower setting. Any advice?

Response wasn't appropriate.

Most thermostats have pre-set stage differentials (or very limited ). Two thermostats may be the ticket to give you the differential you need. You are on the right track, redundant thermostats will give you what you want. I would appreciate a follow up on your progress since I am in the process of integrating a solar system for my domestic heat.

Get two stage thermostats that allow a much larger differential is the easiest way to go since the wiring is already do for this type of set up.

HVAC1000... like which thermostat? It's clear that it's what will work but what thermostats are available that have that great a differential? Manufacturer and model numbers please...

Read


Second Stage Time Delay

Your thermostat is designed to determine the optimum time
to activate the second stage. Simply raising the temperature
in heating or lowering it in cooling will not always force the
thermostat to bring the second stage on quickly. If the fast
second stage option in the configuration menu (step 12) is
set to "OFF", there is a delay from 0-30 minutes depending
on the performance of the first stage of the system.
EXAMPLE: For the last 2 hours the thermostat is set on 70°
and the room temperature is 70° with the equipment using
only the first stage of heat. Since the equipment is keeping
the temperature within 1 degree of setpoint, the thermostat
will delay second stage for a longer time if you manually
raise the temperature or if the room temperature quickly
changes. Once the second stage comes on, it will come on
sooner the next time there is a difference between the
setpoint and the room temperature. The net effect of the
staging program is that when the first stage is capable of
holding temperature, the second stage will delay longer.
When the thermostat calculates that first stage cannot make
temperature in a reasonable time, the second stage will
come on sooner. This built in function automatically optimizes
the use of additional stages of heat or cool.

Unit

http://www.white-rodgers.com/wrdhom/pdfs/instruction_sheets/0037-6841.pdf


There are others out there with similar features but I like this one since it is automatic.