Are you saying the HVAC contractor installed a new furnace without a filter? Did you check to see if the returns had filters?

If this furnace is in the basement, then you only need one filter where the main return connects to the furnace. This is easier than having to change the filter at every return. The filter has to be properly sized based on the size of the furnace and AC. A 4 inch media filter is much better than a 1 inch filter.

If the coil is freezing, then it may be either low refrigerant or lack of air flow. Was the refrigerant level checked when you the coil was freezing? I am not sure I buy the "dead zone" story. What size AC do you have, and was it increased compared to the old one?

HVAC contractors typically give a one year labor and parts warranty. What you have described is a bad installation. The contractor should have fixed this during the first year. Another contractor may be able to fix it, but you will have to pay for it.

If the contractor said he would fix the issue in June, then why the delay?

You're being stonewalled by the installer and I'm guessing the 1 year labor warranty has technically run out by now. However (in the USA) if you reported the problem in writing before the warranty ran out then you still have coverage until this issue is fixed. As Mike says, coil freezing is usually due to low refrigerant or low airflow but there are other possibilities also.

Give the guy two weeks written notice to come out and fix it. If it isn't done by then, you have two options - either get someone else to fix his mess or take him to small claims court.

There's nothing necessarily wrong with going with the lowest bidder, provided you can get service [ problems worked out and fixed when you need them to ].

The problem with low bids, is often times there isn't enough money to cover the 1 year warranty that is supposed to be provided by the installing contractor. That one year doesn't seem like much, until it is. (Sometimes this warranty is longer than 1 year, but the cost is typically higher with those types of commitments and likely require bi-annual maintenance inspections of the equipment.)

If there are installation problems with yours, there are probably problems with others that this contractor performed. (if that's the case, the contractor usually folds and goes out of business takes any remedy you thought you had from this contractor with it.)

The other problem with a low bid, is that the contractor doesn't have the experience to know how to properly bid a job and be able to fulfill the terms of the contract.

The contract is the piece of paper the contractor provided to you that spells out what the job is, what work will be done and what the warranty is on the work, the equipment, labor minus any limitations of such. Like maintenance related repairs and such.

If the contractor didn't provide you with a contract (spells out what work is to be done versus what work won't be done) well that's another problem with a low bid.

Hearsay doesn't stand up in court. Also, A business that is out of business can't be taken to court with any real degree of success.

For these reasons it may be in your best interest to cut your losses. Use this as a learning experience to know what not to do the next time. There is no such thing as a fail proof method when dealing with contractors. Even going with the highest bid can result in disaster.

That's why you want to know the contractor you are using can fix equipment... any one can sell new equipment. Fixing it when it breaks, dealing with problems when they come up is the whole reason you 'should' use a pro.

Pro in this sense is defined as one who can fix and repair things when they break. You will always need someone who can fix things when they break. Installing new equipment every time it breaks is another method, but far more costly.

Your best bet since going the cheapest route would be to get an other hvac co to come in and evaluate the problem.

Thank you everyone for your advice. I have an update: My husband called the owner the Wednesday before Thanksgiving, and they came the following Monday morning (yesterday). To say I am irritated after months of trying to get them here myself would be an understatement. Regardless, a fix has been completed - as to the effectiveness of the AC fix, I could not say as hot weather is months away.

If anyone is interested in specifics, the fix(es) were as follows: the wider AC coil sits on top of the narrower furnace, so they simply moved the furnace over so that the air flow would go over the active parts of the AC coil instead of the dead zone. As making room for the filter, they slotted the filter on an angle into the vertical return ducting next to the coil & furnace by cutting a slot into it and drilling screws into the ducting to keep it in place. I will get a picture later.

I suppose I should get the ducts cleaned as the system has been operating without a filter for 18 months. I am thinking of sending the HVAC company owner a bill - not that he would pay it!

FYI, duct cleaning is often times another scam. They will put out in print a low cost offer to clean ducts, then the bill increases once they come to your home.

The people doing the cleaning are paid on commission, which means their lively hood is dependent upon how much they can sell you and the price you pay.

The dust inside your HVAC system is extremely fine dust (except for the filter return area of the system)... most duct cleaners do not use the type of high end cleaning equipment needed to remove that dust from your system. --- because the product they are selling you --- is mostly a deceptive business.... geared toward 'generating a lead'. That lead 'your call for duct cleaning' often becomes a 'high pressure' sales lead. [ Take it from me, I've been doing this sort of work for nearly 26 years.]

If you honestly think a company could pay a technician, a dispatcher, a manager, liability insurance, commercial auto insurance, office rent and so on... based on $99 duct cleaning price point or less --- uh, no --- that is a scam.

I doubt you could even 'RENT' a duct cleaning machine for $99 that would clean the way you need it to. Don't kid yourself.

I service the Katy, Texas area.

Thanks, Austin Air. We did have an experience with one of those scam companies years ago. We sent them packing, and found and hired a legitimate company with one of the vacuum trucks. We have since lost their contact info, but one of the workers yesterday recommended a similar company.