Tip & How-To about Heating & Cooling

Replacing the Thermostat

If you are replacing a thermostat for your heating system, then there are a few things that you need to be aware of before you start. There have been many questions here of people that are frustrated because they did not take the proper steps to changing their thermostat.

Here are some things that can help you avoid the frustration of having no heat because you did not plan ahead.

  1. If your heating or air conditioning system is not working right now, do not assume that the thermostat is at fault and try to replace it because you think it may be a quick and easy fix to your problem. The thermostat often is NOT the problem and changing it may just confuse things more and make it harder to fix the real problem. Find out first IF the thermostat actually IS the problem.
  2. Before removing the thermostat, make sure, that all power is shut off to the boiler, air handler or furnace, whatever is providing power to the thermostat. If the wrong wires are shorted together for even a split second your will burn out the transformer that is powering the thermostat. By the time you see the spark it is often too late. The damage is already done.
  3. Make sure to label well and securely, all wires and the position of them on the old thermostat. This is so that you know exactly where they were and can reinstall the old t-stat if necessary. Also you have that as a reference for hooking up the new thermostat.
  4. When shopping for a new thermostat make sure you do not fall for the cheaper is better deal. Many times a few extra bucks spent on your thermostat can pay off big time in savings. The better thermostats have a logic built in that will run your heating or air conditioning system much more efficiently. They also use better relays and electronics that will hold up much better over the years. Many touch screen thermostat are also much easier to program and are more user friendly than non touch thermostats
  5. Make sure that if you have a heat pump that you READ the instructions and program the thermostat for heat pumps BEFORE installation. It will NOT work if you don’t. Many of today’s thermostats can be programmed in your hands on battery power before you place it on the wall.
  6. Some thermostats, especially the cheaper ones will NOT work with all heat pumps even though they say that they will. Many times it is very hard for homeowners a DIY’ers to know the difference. If in doubt find out first before purchasing a product that you may not be able to return.
  7. If you have a multi-stage system you will need a thermostat that can handle multiple stages. Make sure that you know if your system is a multiple stage system before you shop and yes, those thermostats will cost considerably more money, they are essentially more than one thermostat packed in one case.
  8. And finally, GUYS READ THE INSTRUCTIONS!!!! This is not a fly-by-the-seat-of-your-pants deal!! I have done many hundreds of thermostat installations and I still get the instructions out of the box FIRST! These products are always being changed and updated. You need to make sure that you know what is going on before tearing things apart.

By following these suggestions you can save yourself a lot of trouble. Changing a thermostat often is not a simple a project as it would look to be. Allow yourself time to do the project correctly and take the time to research the project properly. This will give you the results that you are looking for and a feeling of a great job well done.



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1 Answer

My Bush dryer is not heating up

The dryer Thermostat may have blown.
There are a couple of them:
The high limit thermostat is a safety device mounted on the heating chamber and is designed to prevent the dryer from overheating when the exhaust vent is restricted. A restricted vent will cause the high limit thermostat to trip or activate, interrupting the circuit to the heating element or gas valve. The high limit thermostat is not designed to activate repeatedly like a cycling thermostat and will eventually fail causing a no heat symptom. Disconnect the power to the dryer and check the thermostat for continuity with a multi-meter. If there is no continuity then it will need to be replaced and the restricted vent system corrected as well.
Cycling thermostats control the temperature inside the dryer drum. They are designed to "cycle" the heating element on and off to maintain the correct amount of heat. Cycling thermostats are normally located on the blower housing or elsewhere in the internal airflow ducting. Over time, the cycling thermostat can become defective. Disconnect the power to the dryer and check the thermostat for continuity with a multi-meter.

Temperature sensors are devices that change resistance depending on the temperature. The internal temperature of gas and electric dryers is managed by cycling thermostats on most dryers and by temperature sensors on some electronic controlled dryers. Depending on the dryer it may use multiple sensors to regulate the temperature. You can use a multi-meter to check the resistance of the temperature sensor. You will need to know what that resistance is at room temperature to verify if it is defective. This test should only be done when the power has been disconnected.
IF I HAD TO GUESS, I would bet it's one of the thermostats and I would start with checking these first.
Be aware that it could be many things that cause a dryer to not heat up such as the sensors named above or the timer could be faulty or the heating element itself is bad if it is an electric dryer, or if it's a gas model the ignitor or glow bar may be bad. But again I would start with checking the "fuses / thermostats" first.

Dec 01, 2013 | Dryers

1 Answer

fujitsu heatpump 13 years old is not heating room as it used to.filters are clean.i have gauges and would like to know what pressures are good and what pressures indicate low refrigerant or worn compressor.unit is about a 7kw heating model.

The refrigerant and compressor are related in cooling the room.As for heating problem the thermostat needs to be checked.
if you're used to a certain temperature of air and your heat pump is producing much cooler air, take the following steps. (Note that a heat pump may go into a defrost mode to prevent icing. When this happens, it can temporarily output cold air. Also be aware that the heat pump will have to work harder to produce heat.)

1) First be sure the thermostat is set properly. Try raising the set temperature 5 degrees F. and waiting a few minutes.

2) Be sure the room-heating registers are open.

3) Check the heat pump filter. If it's dirty, change it.

4) Be sure the auxiliary heating elements are working . 

5) Clean the coils of the outdoor condensing unit.
If still the same problem then thermostat needs to be checked and replaced.

Jun 15, 2010 | Heating & Cooling

2 Answers

the heater blows out cold air only.

check the coolant level in the radiator it may be low
and starving the heater core

Jan 10, 2010 | 2000 Chevrolet Monte Carlo

1 Answer

Dryer Heats for 30 Minutes then stops heating

Hello there :
what you are going to want to do is to troubleshoot the heating circuit
if you have a multimeter
there is a thermal Cut-Out switch that is connected to the heater box.) -simply unplug wires and take reading from the end connetors
your reading should be 0 ohms. and nothing else
Next check
a part called the Hi-Limit Thermostat that is connected to the heater box, it should be located closest to the heating element wire leads unplug the wires and take the reading across the 2 wire connections . this should give you a reading of 0 ohms and nothing else.
Now if any of these 2 parts are not in this range they need to be replaced and i would recommend that you replace them as a set cause if one usually goes out then the other one will soon follow ok

I hope this is very helpful for you
Best regards Michael

Jan 09, 2010 | Kenmore Dryers

1 Answer

replacing the thermostat

first thing you need to make the cool down for few hours . then open the upper hose of water that comes from the engin to the radiator . after that you will find the thermostat housing its couple of screws then you can replace the thermostat. pls vote if this helped you
good luck

Jun 03, 2009 | 1999 Isuzu VehiCROSS

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