Pro1 Thermostat T705 Not Working? Try These Fixes

Pro1 Thermostat T705 Not Working

As a homeowner, chances remain that you’ve encountered a faulty thermostat at some point. When your pro1 thermostat T705 stops working, the most common problems impacting the device are mechanical in nature.

This article shares how you can fix such problems by yourself and save a lot before calling a professional.

Signs of thermostat failure

Thermostats typically play an important role in dealing with extreme weather, helping you to warm up or cool down your house easily.

When your pro1 thermostat is not working, you may assume that the entire HVAC system in your home is faulty.

A thermostat is one of the most significant components of your heating, ventilation, and air-conditioning (HVAC) system. It serves as a brain to the HVAC system’s operation. The purpose of a thermostat is to control your HVAC system and manage your home’s temperature.

However, activities inside a thermostat can malfunction and affect the functioning of your HVAC system. It’s, therefore, crucial to understand issues that can prevent your digital thermostat from working properly. While some issues may appear like common sense issues, others can be a little more complicated.

Here are some of the common reasons why your thermostat may fail to work and how you can solve them.

1. No Power at the thermostat’s display

When you realize that your thermostat’s screen is dark, it means no power is getting inside it.

If the thermostat’s display is blank, this shows that the batteries are dead. Sometimes the thermostat can drain batteries, a signal showing that the device is old or faulty.

Your thermostat can also become unresponsive when adjusting the temperature, making no changes in your home’s temperature. These are key indications that your thermostat batteries are dead (dying). All this impacts the effectiveness of your cooling and heating system.

Dead batteries may leave your programmable thermostat nonfunctional, leaving you unable to control your entire heating and cooling system. You may also lose your thermostat’s pre-programmed settings.

If your batteries are depleted, you stand to lose those settings and the ability to control your HVAC system properly.

How to fix:

  • First, you’ll need to use a voltmeter or multimeter to inspect whether the batteries are dead.
  • If the batteries are not working, then you need to replace them with new ones immediately.
  • The batteries should work for several months or even a year before replacement. If you replace batteries in your thermostat as often as once a month, that is unusual. You should, therefore, contact a professional for assistance.
  • If batteries are not the problem, then you need to assess if your thermostat is the cause of the malfunction, inspecting its unit’s ability to connect and draw power.
  • Signs that your thermostat can’t get enough power from good batteries or it is draining them unusually fast show that the device is the problem.
  • If that is the case, you need a new replacement. Repairing the existing thermostat won’t be cost-effective for you.

2. Setting and room temperature doesn’t match

A more complex signal of a malfunctioned thermostat is when your room temperatures don’t match.

Fluctuating temperatures in your house rooms could indicate that your thermostat might be faulty.

In some cases, the wrong settings may cause the thermostat’s malfunction. For instance, you set it to “heat” when you wanted “cool.” Such a wrong setting would trigger the device to stop working. Incorrect settings in the thermostat can also result in the system turning off or on at inappropriate times.

In certain scenarios, the problem is triggered by damaged wiring. Burned, corroded, or frayed wires can prevent the thermostat from working.

Sometimes you will find that your thermostat reading is higher than the settings. That could happen because faulty wiring causes too much heat in and around the thermostat. This could also happen when the thermostat is placed in an area with a high temperature (e.g., in direct sunlight).

Wrong thermostat readings could also happen when you live in a big house with only one thermostat that cannot keep the temperature consistent throughout your home.

Also, your thermostat may start reading the wrong temperature when its batteries are dying, the inside of the device is dirty, or its temperature sensor is faulty.

How to fix:

  • First, ensure your thermostat is in the right setting. In other words, ensure your thermostat is set on “cool” if it’s summer and “heat” if it’s winter.
  • If your AC system is constantly running, you should set your thermostat “ON”. If your cooling/heating system isn’t running constantly, you should set your thermostat to “AUTO mode.”
  • Try to replace batteries to see if it fixes the issue. It will help if you replace batteries in your digital thermostat annually.
  • Every season, you need to remove the thermostat cover and clean the inside using a cloth or a small brush.
  • Try to remove the thermostat cover and check the wires inside to ensure they are all firmly connected to their respective mounting screw.
  • If the situation worsens, then you can consider contacting a technician to schedule a repair, or you can think of replacing a new thermostat.

3. Faulty wiring

Your digital thermostat depends on some important electrical connections to perform its work. Most basic thermostat components, such as heating, cooling, and fan connections.

These connections can become faulty due to corroded wires, loose wires, or any other reasons. As a result, your thermostat may not properly communicate with your AC system.

If your thermostat starts and shuts down continuously, faulty wiring could be the cause. The wire connection wears out with time, which can cause your thermostat to fail.

Besides that, your HVAC won’t function if the thermostat’s wires are wrongly connected to its AC’s heating and cooling system.

Also, incorrectly installed wire can make the entire system stop working at all and cause high electricity costs and uncomfortable temperatures in your house.

How to fix:

  • If your thermostat is not working properly, you’ll need to test its connections manually.
  • Before rebooting any electrical, start by unplugging your thermostat from the power.
  • Diagnose obvious signs of compromised connections.
  • If the wire corrodes, remove the corroded parts using wire strippers and tighten the terminals.
  • If you are not confident testing your thermostat’s wiring network, consult an expert to ensure the work is safely executed.

4. Accumulation of dust

Like several other electrical devices, the thermostat may become faulty if it is allowed to accumulate dirt. Dust, debris, and dirt can cause problems with your thermostat’s mechanical and electrical components, thus making the device stop working.

If your thermostat is dirty, this can cause short cycling (when the thermostat starts up and shuts down continuously) and impact energy efficiency.

Over the years, dust can accumulate in the thermostat’s temperature detection, blocking airflow and vents. These complements help you manage your HVAC and set the appropriate temperature in every room of your house.

How to fix:

  • Remove the thermostat cover and clean out the dust each season.
  • If you don’t feel comfortable exposing the inner workings of your thermostat, use a can of pressurized air to blow through the vents.
  • Ensure that your thermostat is turned off when cleaning, and expect not to turn it back on for at least an hour afterward.

5. A malfunctioning thermostat sensor

A faulty temperature sensor is another problem that may cause your thermostat to read the wrong temperature in your home.

However, this problem can be difficult to troubleshoot. In other words, replacing a faulty temperature sensor is extremely difficult. You can fix this problem by replacing the thermostat with a new one.

How to fix:

  • Before scheduling a replacement, you can try recalibrating (resetting) the digital thermostat to fix the issue.
  • You can also clean any dust inside the thermostat’s cover with a small brush or pressured air.
  • If none of these functions, then the temperature sensor could be faulting. So your thermostat will need a new replacement.
  • You can also contact a professional for further assistance.

6. Your thermostat is becoming old

Like other home appliances, your thermostat will eventually get old and start developing problems like reading the wrong temperature.

Your thermostat will reach the end of its working lifespan. When this occurs, it can cause various problems.

If you consider repairs as a cheaper solution, that could be costly to you. You may end up paying more for repairs than going for a replacement.

Indications (like the thermostat always reads incorrect temperatures, requires reoccurring and constant repairs, has a burnt smell or starts sparking, and is over ten years old) show that your device is old and, therefore, needs a replacement.

How to fix:

  • You can fix this problem by replacing the thermostat with a newer model.
  • You can contact a professional to help you to get the right new device for your needs.

7. Replace Pro1 Thermostat Or Contact Support

If you’ve tried all of the fixes above and you still can’t get your Pro1 Thermostat to work, you can try replacing it.

I personally use the Pro1 Thermostat, which I picked up from Amazon.

View on Amazon

Or contact Pro1 Support.

Note: Only pick up a new Pro1 Thermostat if you’re convinced the one you currently have has too many issues. There’s no point in picking up a new Pro1 Thermostat if the problem with your current thermostat can easily be fixed.

Brady Klinger-Meyers is an experienced writer and marketer with who currently writes for Robodens as well as other popular sites like MakeUseOf and Techzillo. At Robodens, he focuses on general smart home advice with his interest being accessories and gadgets. Read our Editorial Guidelines and Fact Checking process.


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