20 Most Recent Honeywell Electronic Programmable Heat/Cool Thermostat - CT3300A100 Heater - Page 3 Questions & Answers

If there are both an Rc and Rh terminal, there should be a jumper across the two if there is only ONE transformer supplying power to both the furnace and the a/c. Without the jumper, there is no power on the cooling side of the thermostat. Also, the Honeywell thermostat may require a fourth wire for the C terminal. Some thermostats 'rob' control power for their operation off of the R terminal wire and others must have the physical connection to the C terminal, and yet others have batteries for the programming portion and when they go dead, there is no heat or cool operation.

Remove the cover to ensure the batteries were installed correctly. If they were, make sure none of the thermostat pins are bent a little cause mis- alignment with the pin-holes in the subbase. When you determine all is good, reinstall the stat to the base and make sure it is snapped securely in place.

Mhenn, It is my guess that the 'electrical burning' smell is from your heating system. Since there is no smoke and the walls are not warm.... then there is no real problem. The smell maybe just dust has collected in the duct work that is burning off the central heating systems electrical heat strips. If you have electrical heat strips then that may be the problem. If you have a central gas heat system, it may be the same type problem. Hope this helps you. Henry If you need further help, I’m available over the phone at https://www.6ya.com/expert/henry_239f63a136de60f0

Most thermostats have a built in 'cycles per hour' limitation, usually 6 cycles. Some thermostats have an adjustable one, but most usually do not need it. I'm thinking you are hearing a fan cycling on and off on its thermal sensing control and its not the heat at all. Unless you have a fan relay on an electronic control board that is energized in the heat mode, (and it is a gas furnace) it probably isn't the thermostat causing the issue at all. If its an electric furnace, well....that's another troubleshooting issue altogether.

I'm thinking you put in weak batteries. Try another new set, those may have lived beyond their shelf light.

Google Honeywell Tecnical Service. You should find a 1-800 number that will direct you to a technician for residential applications. He will walk you through each step required. Have the model # of your thermostat ready for him. They are quite simple, but almost impossible to dictate in a forum answer.

Google Honeywell Tecnical Service. You should find a 1-800 number that will direct you to a technician for residential applications. He will walk you through each step required. Have the model # of your thermostat ready for him.

See RC and RH, RC is for cool, RH is for heat, you wire the red wire to the RH or red terminal ,either one will work actually but we generally switch the hot leg of power, W is the heat circuit

You most likely have a heat pump, the aux heat (usually electric) comes on anytime the room temperature is 4 degrees below the thermostat setting. Does the buzz go off when the aux heat lite goes out? If the aux heat does not shut off then the primary heater (heat pump) is not putting out enough heat to satisfy the thermostat. I need a little more info. Do you have a heat pump? Is it working?

External temperature sensor or the wiring to it have been compromised.

Look here RTHL2410C 5 1 1 Day Programmable Thermostat

This is dependent on the year. Follow the top radiator hose from the radiator to the motor. The thermostat is generally in the housing that hose connects to. Replace with a thermostat that faults open to prevent future breakdown

Circ ==== Circulate.. To move "Air" around.

I'm not sure if the thermostat is wired correctly. First, the thermostat is wired directly to the outdoor unit (compressor/condenser unit). It is NOT directly connected to the indoor unit. It connects to a low voltage control panel in the outdoor unit that sends a signal to your indoor fan/evaporator. This wire is called the fan relay switch and physically runs between the low voltage controls of the indoor and outdoor units. If the fan relay is bad it's possible that the unit runs continuously. To prevent destroying your outdoor unit there is a safety feature that prevents the indoor fan from shutting down while the outdoor unit is running. If the indoor fan did shut down while the outdoor unit was running than you would slug your compressor. That is, your compressor normally sees refrigerant gas but is instead seeing refrigerant liquid. That would not be good since this scenario would destroy your compressor. It sounds like a faulty fan relay. The actual contactor portion of the relay is in the outdoor unit.

you do not need to hook up the l wire

it means the unit is in the cool mode. it should have a picture of the sun or fire when it is in the heat mode