How to Change a Thermostat

First before you attempt to change your own thermostat you need to make sure you have the right thermostat and correct amount of wires to hook to your themostat.

Lets discuss the proper thermostat first. Many times I have been called to install a thermostat that a customer has purchased themself. Sometimes they will get a heat pump thermostat when they really need a thermostat for gas, oil or electric units. So make sure you know what type of system you have.

Now the wiring for your new thermostat. If you have a heatpump system the number of wires you need should be already there. Most heatpump wires require 6-7 wires , some may need more if you have a two speed heat pump.

Now if you have an air conditioner with either gas, fuel or electric heater in most cases you will need 4-5 wires. Some digital thermostats require a common wire so that the display shows and so the thermostat will work.

To change your thermostat first turn your breakers off that control your air conditioner and heater. Take your cover off the thermostat and access the wires that are connected to the thermostat. DO NOT DISCONNECT YOUR WIRES UNTIL YOU WRITTEN DOWN WHAT COLOR OF WIRE GOES TO WHICH TERMINAL. I would also compare the new thermostat terminals to the old one. If you are unable to figure out how to wireup the new thermostat then call a service company. You will be better off paying somebody to install it for you versus burning something up that cost you more money.

If you feel like you can proceed make sure you look at the diagrams that come with the new thermostat. they will have good information that you will need to properly wire the new thermostat.

Most thermostats have a similar terminal lables such as R, Y, W, E, C, G, and O/B. The O/B is for heat pump units. The O/B is for the reversing valve of the heat pump unit.

So make sure you have the proper thermostat and the correct number of wires needed and follow the instructions. I am going to put down the terminal lables that are most common and describe their purpose. These descriptions are the most common, but you still need to read the instructions and study your wire diagrams with the new thermostat.

HEAT PUMP TERMINALS

R - Power
Y & W - Cooling/ 1st Stage Heat
W2- Electric Heat 2nd Stage
E- Emergency Heat
C- Common
G- Fan
O/B - Reversing Valve

Y/W will sometimes have a jumper to each other or will just have a termial 'Y'.

O/B is for the reversing valve which ever therminal is used on your old thermostat use the same on the new t'stat.

G - is the blower/fan circuit

W2- is the second stage heat/strip heater

E- emergency heat/ strip heaters

C- common

R- Power

AIR CONDITIONER/ GAS, FUEL. ELECTRIC

R- Power

Y- Cooling

W- Heat

G- Fan

C- Common

Premature Compressor Failure

Why do compressors fail prematurely? What I have seen in the 20yrs. doing air conditioning that causes a compressor to fail is units being over charged and air flow issues.
Just this past friday I changed a compressor in a two year old unit. The compressor would not startup, it was locked up mechanically. So what caused the unit to lockup? The unit was over charged. Well when I removed all the freon, the total was 13lbs. Once I completed changing the compressor and recharged the unit the total amount of freon used was 6lbs. The system was over charged by 7lbs. of freon.
So how did it get over charged? It is plain and simple the installers or the startup person did not do their job correctly. Units come precharged. In many cases freon does not have to be added. Sometimes freon does if the lineset is long,but it usually is only a couple of pounds.
In some cases if it has a short line set, freon will need to be removed. Now what can the homeowner do to prevent this? Ask questions to the service tech such as, what is the superheat and split on the unit. These are the two readings I use the most when charging the unit.
There is no standard temperture, the readings vary depending on temperture and humidity,but this will at least let the tech know you have some knowledge about a/c units. If the tech blows you off or does not know, you should be concerned.
Airflow issues that I see most that contribute to compressor failures are dirty filters and dirty indoor coils due to no filter in the system.
This problem can be prevented by the homeowner.Make sure you keep a filter in the unit. Check and change the filter every 30 to 45 days. Make sure you have a good filter also, I prefer the pleated filter over the cheap throw away filter. The most important thing is to keep a filter in the system and replace or clean it regularly.
Unless mother nature does something to kill the compressor you should get at least 10yrs. out of a compressor and with proper maintenance you could get up to 20 yrs. out of a compressor.

Busy Summer

Well to say the lease I have been busy this summer, thats why I have not posted in a while. I thought I would write about some of my service calls this summer. I have had several calls this summer where units were not cooling due to being overcharged.
Overcharged units will not cool like it should,but if its overcharged real bad it will kill your compressor in a short time.

I have changed several capacitors this summer, make sure your capacitors are checked when having your system checked out. Capacitors are alot cheaper than a motor or compressor.

Just a reminder as of Jan. 2006, manufactures will be producing units only in 13 seer or higher. These units will cost more to install. If you are thinking about replacing your system and want to save some money you may want to do it soon before the 10 & 12 seer units are gone..

When should I replace my system?

Customers ask me this question alot. If your system is 10 yrs. old or older it would be in your best interest to start planning to replace it. I replaced three outdoor units in the past 10 days. For a one man shop this is alot of units in a short span of time.
Two of the units were 14 yrs. old and the third was only 7 yrs. old,but it is located near the beach and was badly rusted.

In January 2006 the manufactures will be producing units at 13 seer and higher, so expect higher prices when you go to replace your system. The 10 & 12 seer units will only be around until the inventory are used up. Remember to get the savings from these higher efficient units you will need to replace your indoor unit in most cases. Get at least 2 or 3 quotes and go with who you feel comfortable with, if you do not have a regular service company that you use ask friends & family who they use.

Why does my unit freeze up in the summer

I get asked this question alot and get alot of service calls for this. The two most common reasons for units to freezing up is dirty filters and units being low on freon. Always check your filter montly. Be sure and have a good filter that will keep your system clean. The only thing you can do about the freon is to have your system checked annually. This way if your unit is low on freon, the tech can charge the unit. If your system needs freon every year then you need to have a leak search done on your system. The only way the unit looses freon is if there is a leak. These two are the most common reasons for units freezing up, a couple of other reasons is a dirty indoor coil and indoor blower motor not working.

How to choose a service company

The most important thing to look for is"customer service". A company should treat you with respect, what I mean is if they tell you a certain time that they will be at your house then they are running late they should call you and let you know so that if needed you can reschedule the service if needed. This really shows that they really care and value you as a customer.
The tech who comes out to your house should explain to you what he found wrong with your system and give you options on what needs to be done to fix your system. If he tries to pressure you into buying a new system then this should be a warning to you and you may want to get a second opinion. To help find a good service company, ask friends and family who they use.

Water Leaks

Water leaks can be one of the most frustrating service calls I get. Sometimes it is as simple as a clogged drain line,but sometimes it can be more involved.
Sometimes it is a installation problem,drains ran uphill or double trap. Sometimes it is a manufactures problem.
I will focus on the first sitution of clogged drains. What can a homeowner do to prevent waterleaks? If you have access to the drain line you can pour a mixture of bleach and water in the drain line. You will need to have a pve tee in the drain line to do this. I also suggest the pve tee is capped off. Before you pour any of the bleach/water mixture make sure the water level is not to high in the drain line this could mean the line is clogged.
If you pour the mixture in,it may backup and leak the bleach onto your carpet or flooring. The other suggestion is to have the system checked in the spring/summertime. The tech should blowout the drain and add algae tablets to the drain system. If you have these things done it,will decrease the chance of a water leak.
The last suggestion is to keep your filter clean,if a filter gets real dirty it can cause the unit to freeze up. This can cause a water leak when it melts.
Maintenance is the key to preventing water leaks. Find a good service oriented company and get on a maintenance plan. Next time I will discuss about what to look for in a service company and what I try to do for my customers.

How to Install a Thermostat

How to install a thermostat: "Before you start

Before you head to the store to buy a new thermostat, take a minute to check the number and type of wires attached to your old unit.

If your old thermostat is connected to thin wires coming directly out of the wall, it has low-voltage wires, which don't present a shock hazard.

But if the thermostat is wired into an electrical box, then it's probably running off 120-volt current. Don't try to replace it until you’ve consulted with a licensed electrician.

If you’re replacing a thermostat that contains mercury in a sealed tube, don’t just throw it away. You’ll need to contact your local waste management agency for instructions for proper disposal."

Compressors

The compressor is the heart of the system. The compressor is what pumps the Freon around. If the compressor dies then you will have no cooling. If the compressor is out of warranty then you are looking at a major expense. Now what can a home owner do to prevent a compressor from failing. The first and most important step for a home owner is to have a good filter and to change it when needed.

When filters get dirty it restricts air flow through the indoor unit. When cooling with a very dirty filter it can cause your unit to freeze up. If this happens overtime. I can guarantee you the compressor will die. With a heatpump in the heating mode a dirty filter will raise pressures too high and damage the compressor,which will also cause premature failure and other problems.

A second suggestion is to get a digital thermostat. You may be wondering how a thermostat can help. A digital thermostat usually have a five minute delay built into it so that the unit cannot be short cycled by the homeowner or due to power flickering on and off. Short cycling causes undo stress on the compressor. If the power is flickering,turn off the unit until the storm passes.

The third suggestion is to have the unit checked out at least once a year, it would be best to do a twice a year maintenance. Find a good service company,ask friends,family who they use. Once you find somebody to service your system ask questions on what they check and clean under a maintenance plan. Make sure they check the compacitors for the compressor and motors,as discussed before,a copacitor is very important and can cause problems for the compressor. Next time I will discuss water leaks.