Sunday, October 30, 2011

Amana 90+ Furnace Fix.

Disclaimer: Always follow your installation manual to the letter when installing a furnace or other appliance. Only trained professionals who are licensed in HVAC should attempt or perform repairs on HVAC equipment as personal injury, death, or property damage could result. Improper service methods can render your equipment inoperable.


Amana/Goodman has made an excellent product over the past decade and there are few problems related to their design, workmanship or parts. Almost none in fact save for the inducer motors and control boards on precious few units. One thing that has carried over from the Amana 90% furnaces made in the 1990's is their drain system. They use a hose from an elbow off the inducer motor and one off the collector box on the heat exchanger. When the furnace is installed, there are typically three hoses and some spring clamps to secure them. The instructions in the manual are pretty straightforward as to how these hoses go, but installers can and do misinterpret them out of ignorance or because beer thirty is just a few minutes away. It could also be that it's perceived to be easier and just as good to do it their way.


I've gotten a few callbacks on Goodman/Amana/Everrest 90 percent furnaces because they will run for a few minutes, stop and after a half hour or so they'll run again. The reason is that the installer will install drain hoses improperly. On a typical install with the furnace straight up, there should be one hose off the bottom of the elbow from the inducer motor and the other off the heat exchanger. The one coming from the heat exhanger must drain on the same side as the drain trap, no exceptions. The long hose is for draining from that elbow if the trap needs to be on the opposite side. No matter what, never use the long hose to drain the heat exhanger, or it will sag in the middle and form a trap of its own. The result is that the heat exhanger will fill up with water and the pressure switch will fail to close. The furnace will fail to operate or operate erratically. Another error is to have the pressure switch tubing routed below the inducer fan, as water will pool here too. Maranatha!

Saturday, October 29, 2011

Power Steering Pump Service for Buick Rendezvous.

Disclaimer: I have no control over your work, and any work on vehicles is potentially dangerous for you, your passengers or the public. Improper service techniques can result in injury, death or property damage. The methods given may or may not be typical or accepted service procedure. You must use your own judgement before attempting any repairs on your vehicle or those of others. Do these and any other repairs at your own risk...

Another thing while I'm at it. Power steering noise is usually caused by a worn pump, not a defective rack. Extra effort to steer could or could not be the pump or rack getting ready to check out. A failing power steering pump will likely have leaks as well. A little noise first thing on a cold morning isn't a huge deal. However, once you warm up your ride, the noise should go away and not be heard over the engine. If you heard a whine, growl or groan from the front of the engine even when you aren't turning the wheel, suspect the pump is on its way out.

For nearly three weeks, I've put up with noise from the front of my Rendezvous and since the odometer is ready to hit 150,000 miles in the next month, it was time to replace the power steering pump. On the 3.4 liters, which GM put in most of their cars and minivans in the early 2000's this pump lives at the front of the engine (right side) on the very top. There only three bolts, two hoses and a belt to deal with. The only thing that should give you issues is the low pressure hose that connects to the reservoir. You will need to suck the fluid out of same with a poultry baster or suction gun and use a long handled 3/8 inch socket wrench or breaker bar to release the tensioner to remove the belt. You could use a belt tensioner tool, but the ones from Auto Zone don't work very well on this one unless you add an adapter from your tool box. Take the belt all the way off and set it aside. You'll need a 10mm, 13mm, and a 15mm socket as well as a pair of needle nose pliers, socket wrench handle, power steering pump removal tool (rent this) and 15mm open end wrench.

Before you do anything else, go ahead and check out the two idler pulleys. Grab them, spin them or just take them off and check the bearings for noise or roughness. If they make any noise, go ahead and replace them now. The reason being is that they'll cause the bearings on your new pump, your alternator, water pump, to fail because of play in the belt and heat transfer. These pulley's are about $17.00, while an alternator is about $200 and an A/C compressor is nearly $800. A power steering pump is about $40.00 at Auto Zone and a little more everywhere else, but I digress.

Remove the belt and cover from the front of the engine. Take your wrench and unscrew the pressure line from the back of the pump and your pliers to back off the clamp from the line on the reservoir. There are three 13mm screws holding the pump to the engine and you'll have to get to them through the pulley. Just unscrew them and be careful not to drop them. Take a flat head screwdriver and carefully pry the hose off the spud on the back of the reservoir as you remove the pump. That reservoir is plastic and if you break it, you'll be replacing it. You can make a 1/4 slit in the hose with a razor blade to make this easier, but no more or you'll be replacing the line. Just take your time, because there isn't a whole lot of room to work. Once you get the pump out, make sure all the fluid is out.

There are two clips holding the plastic reservoir to the metal pump. Pry on the tabs with screwdriver and use a small hammer to tap them off. Now you can pull off the reservoir and set it aside. The pulley will also need to come off, so get your tool you rented and follow the directions on the box. You can use this same tool to install the pulley on your new pump flush with the shaft. As always, don't break it as this is also plastic. Use a new O ring on the reservoir and use the clips to fasten it to the new pump. These clips are specific to each side, so don't mix them up. Tap them back on with a hammer until the tabs click in.

Put the pump back in, working the low pressure hose on the reservoir with a straight blade screwdriver. The slit will help the hose fit back over the spud. Be careful of the sensor and wire harness below the pump as you could break them as you manhandle the pump back in. Once you have the hose on, go ahead and slide the clamp back down and start the high pressure line (install a new O ring on the line first) but don't tighten it yet. Start the three screws that hold the pump in by hand and a deep well socket and once you're satisfied they're threaded in right, tighten them up with a 1/4 inch socket wrench. Then go ahead and tighten the pressure line snugly. Reinstall the belt (check to make sure the belt is in good condition) and fill the reservoir with clean power steering fluid. Start the car and move the steering wheel back and forth about 10 or 15 times. Check the reservoir to make sure the level is still full and keep moving the wheel back and forth until the noise from the system goes away. This is called "bleeding" the system; getting rid of the air in same. Be patient, because there will be more effort to turn the wheel and it could take a half hour or more. You could speed this up by putting the front end on jack stands, but this also requires some effort. Just keep turning the wheels back and forth and once it smooths out take the car for a drive and makes some turns with it. The noise should be much diminished if not gone altogether once all the air is out of the system. Maranatha!

Saturday, October 22, 2011

Look for the Obvious.

When I worked for the now defunct Auto Glass Specialists, there was a rather impatient trainer who always started every other sentence with "look for the obvious." This concerned auto glass, but now I apply this truism to everything. If the truism that people that irritate you the most inspire you the most this guy was it. Hopefully, he's doing well and I mean that. However, we're getting off the subject.

I've been a home service professional for 15 years and some months and it never amazes me to see the things people will pass off as repairs. If they work, no harm done, but if they don't they can make the problem even worse. We have some family friends who are looking for a house in the Grand Ledge area. Their children are friends with my son as well. They still live in the same apartment complex we did, but they weren't given a house like I was. They have buy theirs.

Grand Ledge is an expensive place to find a house relative to a good part of the Greater Lansing area. If our friend had chosen to settle in Lansing, she'd probably find a decent place for under $50,000. She did find a really nice Cape Cod in Grand Ledge, move in condition for $100,000. It looks really nice inside and out. Even the basement is clean and the mechanicals are in decent shape. There was new carpeting and hardwood flooring throughout with two full baths and neutral decor. I almost gave this place a clean bill of health, especially after a relative said the structure was okay.

She called me to inspect the furnace, water heater, air conditioner, and plumbing. However, I ended up going over the whole house and found this next to the chimney. The wall board was still wet.
















I went home to get my ladder, came back, peeked into the attic and was facing the chimney. The structure around it were still wet and those two spots were in fact daylight next to said chimney. There was even more daylight showing on the other side and to the forward part next to the water stained wood at the top.









I'll spare you and Blogger the rest of the pictures of the attic as they're redundant anyway. The view outside, considering the one in the attic didn't suprise me. The company these owners (from New York mind you) hired put a new roof on complete with new O.S.B. decking. This was soaked around the said chimney too.








My camera phone probably has a zoom, but I've yet to figure it out. Trust me, the flashing was simply a narrow strip of aluminum folded over the top and sides of the chimey and worked around the roof decking under the shingles. A shorter strip was attached to the front and a bead of black caulk squirted over the top edge where it met the brick. It was one of the most half-assed attempts at flashing I'd ever seen. They would have done better using flashing cement instead of this hack job.




Flashing needs to be done in multiple parts. First, the flashing needs to be set around the chimney so that water can't get in around shingles This involves upwards of twenty pieces of metal including a saddle where it faces the gable and an overlapping flashing to keep surface water from leaking around it. Instead, it flows harmlessly off the roof and into the gutters. A counterflashing is also needed to prevent water from getting in between the flashing and the chimney and the only acceptable way to do this is cut a groove, or reglet into the mortar to attach the counterflashing. The result will be leakproof for a couple decades. However, along with the poor flashing job, no counterflashing was even attempted, hence the slipshod caulk instead.


This is what happens when someone tries to hire the low bidder. Though the materials to do this properly should have only cost about $20, the time to do it right might have taken four hours or more. This could have been the profit margin on this job. Besides, this chimney is as of this writing in desparate need of tuck pointing. This means replacing the mortar that has fallen out before installing the roof should have even begun. Good grief!


To add to this, this is not a deal breaker. I would have still bought the house and fixed the work myself or hired a competent roofer to do the job. Not a real big deal. Stripping off that tacky wall board and using drywall in that closet would have been a no brainer. However, the family buying the home has nary a handyman and one of the boys has asthma. Any mold caused by this water coming in will only make his situation worse. Hopefully, this isn't a problem the absentee owners cannot take care of get my friends moved in. It isn't so the materials as the labor to get up there an do it. There are more than enough competent home service professionals who will fix this at the right price. That someone will not be me. I'm not crazy about getting up on this roof. Maranatha!

Thursday, October 20, 2011

ECM Inducer Fix.



Any one of you who's ever had the misfortune of working on a Carrier, Bryant or Trane furnace with one of these inducer motors knows what a sweet old Bill these can be. The price installed is north of a grand (over $1000) and before they fail they can sound like the power steering pump on your old Dodge. This is enough to drive any homeowner crazy, but the price will be more than that for them to drive you out of their home.


If you've had to suffer through reading my fine posts, you know full well my opinion of these little darlings. I recommend replacing the furnace if it's a Carrier or Bryant, or at least upgrading the works if it's a Trane. ECM motors for an inducer assembly are great in theory, but from a durability standpoint they miss the mark. Okay, so you want an alternative to kicking yourself and spending hundreds of dollars. I have a crazy 21st century fix that just might work. Really, this qualifies as a redneck repair. However, it might quiet this motor down and could even prolong its life. As long as you're careful, the repair will cost you nothing.


The picture may or may not look exactly like the one you're dealing with, but the rectangular housing on them is all the same. This is what you need to concern yourself. As always, I have no control over your work and the risk is breaking an expensive part and having a no heat. The little circle in the center of the unit is the fan for the whole works. There are fins that draw away heat from the circuit board that lives underneath. G.E., in all their reasoning forgot to include some kind of spacer behind this fan and it can walk on the shaft into one of the I.C. (integrated circuit) chips behind it. This plastic rubbing against the silicon (not silicone) could be what's making the noise as long as the bearings are still intact.


To fix this you're going to need to pack your patience, a small Phillip's head screwdriver, a pry tool, and possibly a plastic fork with one of the inside tines removed. That pry tool can be a small flat head screwdriver or butter knife and the plastic fork can be your hand, but no metal fork should be used. Use the Phillip's screwdriver to remove the two screws and the pry tool to unclip that plastic cover. Take your time in getting this off so you don't break it. Once this is off, you'll see a circuit board and the little plastic fan. Gently rotate the fan with your fingers and if there's any resistance, check what it's rubbing against. If it's rubbing against any part of the board behind it, you can proceed. If not, you need to replace the assembly. You can pull the fan forward with your fingers to free it up, or use your fork to do the same. Do not pry against the board and if the fan gets bent in any way, you'll have to remove it and straighten it out so it's flat. Either way, make sure it clears the board and when you reinstall the cover, well the cover. Turn the fan with your finger to confirm this. As long as your satisfied with your work, turn on the furnace and it should be as quiet a church mouse. If not, either the motor is screwed or you didn't get the fan on right. The fins need to face the front and not the board. Maranatha!

Sunday, October 16, 2011

New Job.

I hate to say goodbye to an employer, but the fact is that being the only technician with a growing family has meant that I've given up a lot of things. Being of the X generation, I admittedly value work and life balance. Being tied to the phone 24/7/365 has had me burned out a long time, et cetera. As of last Wednesday I'm working for another firm closer to home with a take home vehicle and only on call every third week. Huge load taken off. I pray for and wish my former employer love in Christ, blessings and prosperity. Hopefully they'll get lots of work and be able to expand, hiring one or two techs in addition to the one there. I also hope and pray for their continued success and being able to take care of their customers. I love all of them.

Saturday, October 15, 2011

How To Clean Seats, Or Not...

A disclaimer: If your seats have airbags, heaters or other electrical accouterments, better move along on this one. Water and electricity don't mix. This is on the rear seats that I could take out without much difficulty. Think long and hard about doing this on an older vehicle in the salt belt as you could break off a bolt. Your seats and car could be sidelined a few days while they dry. Remove the seats from the car before you try this fix. As you're the one who has to decide whether or not to do this, you assume ALL responsibility for the outcome, come what may. Do this at your own risk. Do not use this method on leather or vinyl or I'll laugh at you personally. These are on cloth seats and only as a last resort.

My Buick Rendezvous is now rapidly approaching its 8th birthday, despite the 2004 model year horse feathers. It's also near the 150,000 mile mark and still going, poor wheel alignment notwithstanding (I can't redneck this one), but the interior looks like I've been carrying garbage in it for 16 months. The front seats I've covered (for now) but the back seats aren't much of an option. The light tan interior shows every stain, scuff etc for all posterity despite any method to clean them. I could attempt to recover them, but this is a spendy decision.

What you're going to need to do this are a few rags (NOT the red shop rags) a scrubbing brush, some pretreater (Resolve works great, but you can Shout it out) a spray bottle and some laundry detergent (Tide works best, but nothing with red dyes). You'll also need a hose and a nozzle. The spray bottle works best if you fill it nearly all the way with water first and then add about a teaspoon of laundry soap. If you add the soap first and then the water you'll end up with a yucky, bubbly mess in the bottle that won't clean anything and will be impossible to fill. Move the bottle around to mix, but don't shake it. Remove the seat or seats and spray the mixture over them. Just wet the whole seat down, but don't saturate the fabric. Too little is better than too much. You can add a little more to the stains, but easy does it as too much will be impossible to rinse off and make it easier to stain in the future.

Take your pretreater if you must, but do so lightly. Use a scrubbing brush to loosen the stain and rag to blot it up, or just use a rag on lighter fabrics. Again, don't work it too hard or you'll be recovering the seats. Once you're satisfied that every thing's done, get your hose and spray them down. If you see any dirt or in my case dyes from something the previous owners left, spray until the water runs clear. Do enough to make sure the soap is out and no suds remain. This can be done on a deck, but a cement driveway or patio works better because of the amount of water being used. Try your best not to spray water into the mechanisms or you'll have to oil or grease them later. If you have a few sunny days with low humidity, great. If not, better put them under an awning or in a garage to dry naturally under low humidity. If you have to put them in a confined space, a dehumidifier or room air conditioner is mandatory to prevent mold. I just set mine on my porch and will have to vacuum the leaves off of them.

Never put them back in the vehicle wet as you'll likely damage the electrical connections inside with the sudden burst of humidity. Once they're dry to the touch, use a rag with some WD-40 and wipe off the metal parts underneath. Put some Scotchgard on 'em and put back in the vehicle. You're done. Maranatha!

Saturday, October 8, 2011

An Expensive Call, Part 3

To recap what went on, this furnace had not been maintained in several years. The drain trap to the air conditioner coil plugged and allowed water to pour all over the furnace, into the burner box, the pressure switch tubing and into the pressure switches themselves. To add to the misery, it also got into the electronics and onto the inducer motor. This only corroded the board a bit, but could have put said motor out too. However I couldn't prove this, but I could prove the motor had failed.



This is the furnace with the ECM inducer; the black rectangular beast in the lower right hand corner. They were very failure prone, especially if the cooling fins weren't cleaned regularly. If you still have one of these and it still works, get it serviced regularly. These motors are usually quiet when they run, but when they start whining, you need to plan for a replacement or be left with a no heat.

Does this mean I'm a bad technician? Well, Trane in all its wisdom, subbed out what's called an ECM motor for their blower and inducer motor assemblies. They run on direct current or DC, which is supposed to use less electricity and be more reliable than comparable A/C units would be. This wasn't exclusive of Trane, but Carrier, Bryant and possibly others used this same system for the inducer on all their high end 90% furnaces. The only difference is that Trane abandoned this system and went with three-phase for their inducer motors on their variable speed furnaces. To my knowledge, Carrier and Bryant are still using the ECM which is supplied by G.E. and failures are still happening. The three phase inducer setup Trane now uses is practically bulletproof; I've changed only one in 5 years because the bearings locked up.

With this upgrade in technology, Trane also made the ECM style obsolete. So now instead of replacing the inducer, which was a ten minute job and still cost the customer close to $600, the entire wiring harness, control board and inducer has to be upgraded to the new style. All this is to the tune of over $800 and at least an hour's worth of work if all goes well. This one didn't because the person who installed it didn't properly adjust the manifold for high and low fire. The lack of maintenance sure didn't help either.





The new drain trap is now installed on the A/C coil, note the clean out tee. I also left a couple joints unglued to facilitate cleaning of the trap.








Here's the new wiring and three phase inducer motor installed; note the wiring is not completely hooked up or tied back.


After nearly three hours of finagling with this beast, including the gas pressure and wiring, it ran nearly as good as new. I replaced the ignitor, because the old one was over limits. I also cleaned the flame sensor, checked the burners and cleaned all the drains. In addition I also checked the gas fireplace out because the customer indicated the remote control wasn't working right. I confirmed it wasn't after another half hour of messing with it. The total bill for this call, including trip, diagnostic, installation of a KIT 15017, two pressure switches, hot surface ignitor and a drain trap came to $1153 and some change. This was about $350 more than my Miller for my mobile home cash and carry cost and would have nearly paid for it installed. It took me five hours to install the Miller and three to fix the Trane. However, it would have run over three grand to replace this with a Goodman (well over that, I might add). Lesson learned: Condensing furnaces (90%+) need annual maintenance and so do air-conditioners of any efficiency.

Even though the bill was expensive, this could have been much, much worse. If this had been on a first floor, or in an attic the consequences could have been disastrous. Damage to walls, ceilings, floors and furnishings could have run into the tens of thousands; not to mention the health hazards of mold and mildew. Any way you look at it, maintenance on your HVAC equipment needs to happen. This customer took to putting a reminder on her smart phone so hopefully this won't happen again. Maranatha!

Friday, October 7, 2011

An Expensive Call, Part Two


If you mix electronics and water, water wins every time. The damage to this furnace was far beyond asthetics and nullified the functionality of same to that of a $3000 paperweight. The A/C was also 20 plus years old, the drain pan was metal and full of rust (sorry no pictures). This bears mention that the air-conditioning system or at least the A coil should have been replaced inside to prevent damage to the furnace. The coil wasn't even accessible to clean and the trap didn't have a clean out tee, which should be code on any install involving a new furnace or A/C. This is also a health hazard with the mildew, although regular cleaning of the air cleaner or filter changes can help prevent this problem. Still, every install I do has a clean out tee.




However, this board still worked and showed a code three, which is an inducer error.











Note the patina of rust at the bottom of the cabinet, this shouldn't cause any more problems though.












The electronic air cleaner was also heavily involved and hopefully it still works as the customer was still in the process of cleaning it when I left the job. Considering you can slide a media filter in this housing, it's a low priority.



Here's another shot of the trap I cut in two. Although there's some space at the top where I cut it, the rest of this is packed with dirt. No wonder it wouldn't drain... Stay Tuned!

Thursday, October 6, 2011

An Expensive Call, Part One

As a disclaimer, this was only one result of of some very unfortunate circumstances that happened to the customer. The purpose of this and every other post of this nature is for informational purposes only and to hopefully save someone from expensive repairs on their equipment. I am not picking on anyone and for privacy, all circumstances will not be mentioned in this post. This article is not to attack any brand in any way. Trane makes a good, reliable product that's very service friendly. Brand names are far less important than the installer putting it in or the service tech working on it. Enough said,

Recently, I was called to a no heat on a Trane XL 90 the customer said was leaking slime from the bottom. In the brief time I've been doing this work I have never heard of a furnace "leaking slime" out the bottom. This is what I found when I arrived...


The "slime" was dirt from the air-conditioner coil pan which can be seen in the background and the black stuff is mildew from same. The entire drain trap was plugged solid with debris and the water and dirt overflowed from air-conditioner drain pan into the furnace. The electronic air cleaner had not been cleaned in three years, which made this much dirt getting into the trap inevitable. The trap is in the foreground, cut in half. If this was all that happened, it would have been bad enough, but the worst is yet to come. Stay tuned!

Monday, October 3, 2011

Rolling Out.

Today, another eight o'clock one at that. All that I can say is that every day has an evening. A customer called a few days ago with a boiler problem, with the office girl asking if we fixed boilers. "We do fix boilers" was my reply. She's still new here, capable as she is and with that I was on a boiler call to get them heat and hot water. This was in Laingsburg, the office is in Lansing and I live in Grand Ledge; so this was going to involve a lot of driving.

Five fifteen and I parked the truck in the customers' driveway, greeted them at the door and got to work. The complaint was that the burners inside the boiler would work great for a few seconds and then the flames would develop a mind of their own. Instead of dutifully going upward into the heat exchanger, they would creep out of the burner box to the front of the boiler; scaring the customer and sure surprising the heck out of me. The customer alluded that the gas pressure was too high and that was the reason for the flames leaving the boiler, or "rolling out" as they were.
The propane supplier had already replaced the regulator. The customer had already called someone else to do this, but from what this writer saw, the repair was anything but successful.

I pulled the burners and vent off the boiler and with a flashlight and mirror, looked up inside. The entire heat exchanger was caked with soot to the point you couldn't see through it with said light. After an hour and a half of brushing, using compressed air and a vacuum cleaner to clean up the soot, I finally got the boiler back together and back to rights. $259; $170 to clean the heat exchanger and $89 for the service call (my employer doesn't take off the diagnostic charge for a repair) seemed like a lot, but paled in comparison to what the other contractor wanted to charge.

Admittedly, I'm not the sharpest knife in the drawer. However, this guy was a couple pancakes short of a stack. He not only intimated to the customer that propane burned dirtier than diesel fuel, he also said the burners would need to be cleaned to fix the problem. The sum for this work and advice, more of a whopper than any real work, was over $450! I got the thing working again for less than half of that, the trip and diagnostic not withstanding. Understandably, the customer, a scientist and his wife, rushed this huckster out the door.

First of all, I only touched the burners to get them out of my way as they were perfectly clean. The reason the boiler sooted at all is because the manifold pressure was too high. Over 20 inches of water column to be exact. Propane, or LP needs about half that number to burn clean, or excess carbon will condense on the heat exchanger as soot, plugging it up. No wonder this one wasn't working right. The natural tendency for hot air to rise was defeated by the soot, and since there was no other way to go, the hot air and the flames chose the next easiest route. This was right out the front of the boiler.

If you're having this problem, the tech needs to take the time to take the burners out and the vent off if this is a natural draft appliance such as an older model furnace or boiler (most boilers are natural draft, but use a vent damper to help save energy). He or she needs to look at the heat exchanger top and bottom and if there's soot, or rust, they need to clean it out and not condemn the equipment unless the heat exchanger's cracked or the furnace is in really poor condition (see previous posts). Home ownership is expensive, why make it more so? Maranatha!

Sunday, October 2, 2011

Top Causes of Furnace Failure

Caution, this is a rant. However, it's an educational one. Hopefully, someone can learn something when it comes to making sure their heating system actually heats when you turn the thermostat on. These are in no order, and are by no means the only reasons furnaces give up the ghost. All are 100% preventable with a little common sense and a few dollars spent now instead of a bucket load later.

1. Failure to maintain equipment: This should be an all-encompassing cause, but I'm writing this article; so it isn't. Not getting a tune-up, clean and check, etc will mean that your furnace will suffer cataclysmic, catastrophic failure of the worst kind. Then you can complain bitterly about the cost of a service call, parts, etc to the hapless tech who came to pick up the pieces. For the details, read on. A qualified service tech should do the work. Not all handy people are up to the task, but most of it is pretty straightforward.

2. Failure to change filters: It bears mention that any equipment that moves air will need a filter changed regularly. If I had a dollar for every time someone bought a "high performance" filter that was advertised "up to three months" my lot rent would be paid for the month. I don't care what the manufacturer says; if you have a one inch filter, change it monthly. If you have central air conditioning, change it monthly during the cooling season too. Already heard the excuse "I only use my air on really hot days." Change the filter already. You're tearing up your equipment if you don't.

3. Failure to maintain condensate drains and pumps. These need to be cleaned out twice a year to stop the traps from overflowing and ruining the sheet metal and electrical parts in your furnace. Water can also get into safety switches can create a real mess. Cleanout tees for the condensate drains to the air-conditioner are a must, but few contractors install them voluntarily. Get them to install one or find another contractor to install the equipment. Water and bleach needs to be run through the drains twice a year (easy on the bleach). Condensate pumps NEED to be taken apart and cleaned as they accumulate yeast on the inside. These will KILL the pump and will ruin a lot more than a furnace if they call it quits. 90% efficient furnace will have condensate drains that MUST be cleaned out annually.

4. Failure to have a qualified contractor and installer do the work. 90% of the reason a furnace will prompt a service call is because the installer either installed too big a furnace (failed to do a load calculation) wired the humidifier or thermostat wrong, or my favorite, didn't plumb the condensate drain lines properly. Another close relative of these are the pressure switch lines on Amana and Goodman furnaces, where they hang low enough to stop your equipment cold. Water pools in these low spots and they'll run for a week or two before setting an error code. The cure would be to shorten and reroute the line. The point is to get a trained, qualified installer to do the work. This is your home, and no place to cut corners.

Maranatha!