Heating Problem

[johnk]

You need return air vents so the heat is pulled across the rooms. The only rooms that won't have them (usually) are the kitchen and bathroom..

 

[Jagmandave]

I put my own furnace in a few years ago, replacing the original. The first unit I bought was so much smaller in size than the old one, that I could not figure an effective way to hook up the old ductwork. Fortunately they sold the same furnace in a bigger "package", and allowed me to return the first one. It's worked fine since day one, and my gas bills were 1/2 the first year. Of course, gas prices have almost doubled since then, so I'm pretty much back where I started monthly cost wise, but I have a new furnace!

Oh, cost me about $700 for a new lennox, 3 years ago.

 

[Birdhunter1]

</font><font color="blue" class="small">(
uhh...150,000btu for 2200 sq. ft? /forums/images/graemlins/blush.gif

They sized the house using the finger equation or you have holes in your walls.

Seriously, a load calculation should be done on your house to determine the load. As far as the coil, depends on a couple of factors, but...shouldn't be a problem as long as you can do some sheet metal work. But...keep in mind, different size furnace MAY require different size duct work to "maximize" the airflow from the furnace and a/c.

)</font>

He's in Michigan, where the outdoor design temps are muc lower, for longer, than the outdoor design temps where you are. Most likely that 150,00 BTu isn't too far off if it is even off at all!

 

[Sigarms]

You're correct, wasn't even thinking about the state. One reason though to do the load calc.

 

[Sigarms]

The reason I mentioned return air is not because of vents, but due to propper sizing of the return air to maximize air flow across the coil and heat exchanger. You would be surprised how many "cracked" heat exchangers are due to the return air being to small.

 

[Sigarms]

Had a residential house I had saved in my system. Fourteen hundred sq. ft (and all info needed for the load such as R value, windows ect...). Here in N.C load was 36k for cooling and 32k for heat. Only variable changed was location of state, from N.C to Lansing (sp?) Michigan. "New" load was 32k for cooling and the heating increased to 44k.

Program was Wrightsoft.

 

[Mrwurm]

Ok guys, here is the latest. The supplier said they can get the gas valve in about two weeks, but they can't get the orifices ! They let me cancel and they refunded my money. Done.

Next, I found another supplier who said they could get the parts in two to three days (here we go again). They called me back and said that they can get the valve in 10 days but that there are only 3 orifices in the supply chain right now. (I need six) The manufacturer lists them as backorder. They cannot even estimate availability.

I have removed the orifices and they are size 54. The installation and parts guide that came with the furnace lists all natural gas models as using size 42.

Anyone know for sure what drill size that is ?

 

[Bird]

Jerry, I don't have an answer, but look at this site and see if something there can help.

 

[Mrwurm]

Ok, from Birds link, it looks like a #42 is .0935 in. Trouble is, the orifices are sized in .004 increments. So, if I'm off by .004 inches, I'm into the next size. I'm not sure how I could size to that tolerance.

Would a simple #42 drill run through the orifice do the trick, or does it need to be precision reemed ?

Thanks Bird

 

[Highbeam]

I'm thinking this is a drill press job just so the hole is straight and since you are shaving such a small amount off.

 

[Sigarms]

The PROBLEM is that it's like oil nozzle sizes, there is no "national standard".

I would just talk to "tech" at Heat Controller.

 

[Mrwurm]

Ok, here is what I found out:

A #54 drill is .055 inch
An 16 gauge wire is .051 inch
A 16 gauge wire fits very nicely through the #54 orifice.

Now, this could be a coincidence or it could mean that
these orifices are sized just like standard drill bits.

Assuming the above:
The #42 orifice that I need coincides to .0935 inches.
A 3/32 drill bit is .0937.
.0937 is right in-between a #41 and #42 drill.

I don't have a drill set with numbered sizes. Tomorrow
I'll see if I can buy a few #42's. If not I may just use the
3/32. I believe that should leave me enough range to
adjust to a blue flame.

This is making me nuts /forums/images/graemlins/confused.gif /forums/images/graemlins/mad.gif

 

[Sigarms]

Fact is you can "correct" the current problem now (valve and orifices) and the furnace may be fine for the next 10 years.

But...if it is this much trouble just to get a gas valve (what are you looking at so far, 3 weeks or more?), you run the chance of having the same availability on other parts as well.

Problem is you "usually" only run your furnace when you need it (when it's cold out).

Say in December you need a limit switch or ignition control board (or pressure switch). You want to run the risk of having to wait that long for a "common part"?

Considering the unit is over 10 years old and from the current "issue" on parts, get a new furnace.

 

[Egon]

When I drilled out some orfices had a hard time getting drill bits small enough. Finally found some that came in pencil type case that also acted to hold the drill bit as you hand drilled the orfice. Was very easy drilling. Hardest was trying to see what the bit size was.

Hope all goes well.

Egon /forums/images/graemlins/grin.gif

 

[Mrwurm]

Ok, folks, good news . . . I have an operable furnace /forums/images/graemlins/grin.gif I had help from several TBN'rs but one in particular spent some time on the phone with me. He instructed me as to how to do some checking and calculating and drilling. Result, I have heat /forums/images/graemlins/cool.gif If the TBN'er would like to be recognized, here is your chance to take a bow. (or fade into obscurity, your choice.)

I clocked the meter and found that I'm actually running a bit under the rated capacity of the furnace but the flames are nice and blue, no CO2 emissions reported by either of my NightHawk detectors.

In a week or two, when my parts arrive, I plan to install the original equipment parts. Till then, I'll be keeping a close eye on the operation of the furnace.

Ok, here is the interesting part. I have participated in many friendly debates here on TBN about whether one should drill their ROPS. I drilled holes in mine to mount my lights. I have been roasted by many and admired by few. Drilling must be in my blood, for I feel I'm about to be roasted for drilling again. Except this time, it was gas orifices and not a ROPS.

 

[VA_Joe]

Congrats on the successful conversion. Heat is a good thing.