ULTIMATE FURNACE INSTALLATION INSTRUCTIONS

As this is a DIY Blog, and I get all the questions that come my way. Today I am going to address a question that is coming up a lot

If I am going to do my own Furnace Installation, should I choose a high or mid efficiency furnace? The choice is not so clear so here are some tips to make the choice easier.

The difference in a high efficiency and mid efficiency furnace installation can be considerable if the equipment is installed correctly. For a high efficiency furnace to work correctly it will have to be installed with two pvc pipes going outside. One to carry the product of burning gas out of your home. The other pipe is to bring in fresh air for the furnace to use for combustion.

Now this perplexes some. Why bring in fresh air to burn? Is there not plenty around the house that you do not have to bring in freezing cold air, I dont see how this helps. Thats a great question all. Heres why. When the furnace is burning air naturally from your home it is creating a negative pressure in your home, and all the while the atmosphere pressure on the outside of the house is pushing in with 14.7 lbs of pressure. This causes cold air to find every small opening in your home (like electric outlets, cracks in windows, small cracks from doors) and push that freezing cold air into your home making it very inefficient.

Now if we bring in a little bit of fresh air and pipe it right into the burner chamber on the furnace we increase the efficiency buy not circumventing those natural forces. In fact in theory, and there are some furnaces out there that do this, in theory if you could pressurize your home to 14.8 lbs pressure or close to it, you could possible heat the house with a candle or two as there would be no cold air infiltration.

I know thats a long story just to say, make sure you install the intake pipe………

The efficiencies work like this – if my furnace is 80% efficient, for every dollar I send to the heating company 80 cents would have been to heat my home, the other 20% went into inefficiencies . So a 95% Furnace is a booya no.

Now on to choosing. If I were short on money and I already had a 80% efficient furnace I would more then likely go for another. They are cheaper up front and there is no real added expense to install other then the furnace itself.

When you  choose to install a 95% furnace and you have a 80% already in your home , the furnace will not only cost more you should take the following into consideration.

• The initial cost is more for a 95% furnace, but you could make that up in a few year with efficiency.
• You will have to install new pipes to the outside of your home – two to be exact, this is extra cost
• If your hot water tank is left alone piped into the chimney (called orphaned)   It will need to have a chimney liner installed so the flue gases can get out of the home and not fall back down the chimney and eat at your chimney. These can be a considerable cost depending on the access to your chimney and the style (but thats for another article)

That should cover most of the needed data to answer the question–  New Furnace Installation 95% or 80% ?

This brief tutorial will help you to Understand your Thermostat. Espically when it comes to Furnace Installations.

So what is a thermostat. T-stats (thermostat for short) are used in a variety of applications, In fact your cooking appliance most likely has a thermostat, so does your car. The t-stat were going to be talking about is the one on the wall in your home.

What does it do? Basically a thermostat is a switch. Just like a light switch when we want to turn something on (other then our spouse) , we just flip the switch on the wall up.

The thermostat is exactly the same principle , but it does the job without human interaction.

How does the t-stat sense temperatures?

Good question . The old style had a piece of metal in it that expanded or contracted when heated or cooled, when the metal was heated it expanded enough to flip the switch, then when it cooled sufficiently it flipped the switch the other way.

The new electronic t-stats have sensors that will change an electric property and send a single to flip the switch on or off.

Here is a basic and simple wiring diagram of a thermostat , and some explanation

So here is the deal……

R = Color red , and Power coming from the transformer on the Furnace

W = Color White , and this is the wire that send 24volts back to the furnace when the t-stat calls for heat. That 24volts starts the heating cycle

G = Green in Color (see a pattern) , this is used to manually start the fan in the furnace (most of the time)

Y = Yellow for color, and this will send 24 volts back to the furnace to start the AC cycle (if you have ac, if not you dont have ac you dont use this terminal

x (sometimes B and sometimes other colors) = usually black or blue in color, this is the common, or ground side of the transformer in the furnace.

Not all thermostats are the same , and many of them will have different parameters that the manufacturer would like you to adhere to. Those instructions are very important. READ THEM CAREFULLY BEFORE YOU DO YOU OWN THERMOSTAT INSTALL. If you have any questions you can always email me and I will try to help.

Here is another fine resource for thermostat wiring , Probably the most comprehensive i have ever seen . So if your stuck or have a more complicated system try this link

Hope this all helps with your furnace install – If you looking for a full set of written instructions look at my home page where you will find The Ultimate Furnace Installation Instructions

Regards Tony