Air Conditioning - Thermostat Cycling

My programmable t-stat cycles every 30 seconds to 2 minutes while running heat. This is bad isn't it? The strange this is it comes on when the temp reading is the same as the temp setting? Could it be just a bad t-stat?

Depends on what model/brand of t-stat you have.

Honeywell uses Cycle per Hour "CPH", it may be set too high

Others uses temp offset like .5 , 1, 1.5.. ect.. it may be set to close.

Is this a new problem? Is the stat located near a supply air vent?

It's a Honeywell CT3500. It's a new house, to me at least. It's in a big room, but non of the vents are blowing directly on it. The manual doesn't tell you how to set the CPH. Maybe it's hidden somewhere in the customize mode? Honeywell has this link, but it's a dead link:

"Why does the system come on early to reach the set temperature?"

Download link below.

www.gogeisel.com/geiselonline/support/Honeywell/CT3500_CT3595.pdf

Page 12

Go to system type, #3

Thanks for all the help. I adjusted the setting. So far so good. It's been off for over 2 minutes!!

What was it at before?

It was set to #9.

Oh wow! No wonder why it went on and off soo often!

Honeywell's temp reading is going to stay pretty close or on set point. Also, I think you will see some saving on the gas bill since the system is not cycling on and off often.

What a difference this change made overnight. It's actually warm in the house and the cold spots are much warmer. It is an electric system. Do you think it will hurt it in anyway running in this mode?

This all electric heat? Wow! I can't imagin your light bills.

No, you are fine with that. With the longer run time allows other area to warm up otherwise, with the short cycle the heat doesn't get a chance to get to the far end of the ductwork to warm up that room.

If you find that the room temp over shoots the set point, then increese it to 4. Otherwise, leave it be and enjoy the warmth! :-)

[QUOTE=Jay11J;1110442]This all electric heat? Wow! I can't imagin your light bills.QUOTE]

The bills have been almost double of what they were in the summer. I almost had a heart attack when I saw how fast the meter was running while the heat was on. I was on the verge of replacing everything! I hope this does lower the bill a lot. I really do appreciate all the help.

You may save some money, But I don't plan on seeing a lot since electric heat is very expensive. Do you use set back?

Where are you out of?

Maybe a heat pump (Unless you got one, and it's not wired up right for it)

I don't know what "set back" is. I really don't know much about HVAC. I had someone inspect the system & he said I don't have a heat pump and recommended one. I did tell him about the frequent cycling, but he didn't even look at the t-stat. It was a free service call & of course he tried to get me to buy a heat pump right then & there. So now I'm wondering if I really do have a heat pump. What is the easiest way to tell?

The t-stat you have is a programable t-stat where you can program it to set back say 62 degrees over night when you are sleeping, and bring back up to temp at 6am, back down when you leave for work. and back up when you come home. They say on an avg you will save about 10% for every degree you set back.

What is the brand and model # on your outdoor unit? (model# will be on a sticker on the side of the unit)

Is your air handler in the basement? Model number will be on that as well.

Not to change the subject, but still an important point. In some cases, perhaps many, a free service call is just a visit by a salesman who will try to sell a new system. I guess the old saying, "you get what you pay for" applies. If you really think about it, how could a company stay in business if they really gave stuff away. They can't. A free service call usually equals higher prices for repairs and high pressure sales for new equipment.
The honest folks in this business, including myself, charge a normal fee for a service call. Anything less should make you suspicious.

I agree. I've gotten estimates for windows, ductwork, etc., but it was like dealing with a car salesman. I got the free call through Home Depot. I've had Home Depot do some installations for me in the past and never had a problem. They use local contractors and they show up when they say, unlike every other contactor I used before. So with the good service in the past I went with HD again. Plus, the HVAC guy didn't really push it on me when I told him no.

I don't set it back overnight night, but I do when we are working. About 4 degress lower than when we are at home. I'm down in Texas. I moved here as a little kid the first thing I asked was "where's the basement?" Man o man do I wish I had a basement.

The outside unit is a Carrier 38TK. The inside unit in the attic is a Bryant FC4BNF060.

Ok, from what I've read is that your indoor air handler is heat pump ready, So you just have to get a outdoor unit that is a heat pump, and a T-stat that can control a heat pump.

I'd get a dealer in to look at it closer to make sure the air handler is set up to be used with Heat Pump.

I got the new electric bill after adjusting the system to type 3 and it's actually over 50% higher than usual. I don't get it and I can't afford that much more every month. I guess I'm going to have a heatpump installed.

Go to http://warmair.net and compare fuel cost for where you are there in Tx. If you have electric for heat now I cant see why you dont have a heatpump.

The outside unit is a Carrier 38TK. The inside unit in the attic is a Bryant FC4BNF060.

I wonder if the heat pump went out and the outside unit was just replace with a AC unit . To cut the cost down?
If you do go for a new unit stay with the R22 it will be around till 2030

Hi Ed,
Thanks for the info, but I'm a bit lost. Where do you do the fuel costs comparison. This is all I found:
http://www.warmair.net/html/fuel_cost_comparisons.htm

Also, What is an R22? Sorry to be so ignorant!!


I think the previous owners did replace the outside unit w/ a cheap one because they new they were moving soon.

When you go to that warmair.net look over on the right side for fuel comparison.
Now Down the line we have to stop using freon R 22.But that is till the year 2030 and then some. The new freon thet we have for the units is R410a. It works at a higher Psi and cost a lot more than the R22. Also if you have a leak in the system you might have to take out all the old freon and put all new in. Not just top it off like you can with the R22.

I am sure you guys has been getting the cold weather like we are. so if you are having the colder than norm, yes, it will cost more to heat.

The 3CPH won't have affect on that.

Where are you from? I am sure the "Heating degree" days are higher than last year.

I've been in this state for a long time and it does fluctuate year to year, but I'ver never had a 50% increase in one month.

I got a quote for a new Carrier 5 ton, 13 SEER for $3600. This also include a new t-stat and installation. The same company also said they could bring my attic insulation up about R30 for about $1250. I haven't been able to shop around yet since I got the quote late today. How does this deal sound?

Id say spend more of your $$$ here now and be done with it. For it all for sure get 3 bids on it.
Ok your down there inTx So think about the AC first. You say 5 ton. Did they do a heat lose and a AC load on the home ??? Id for sure look into a two stage AC heat pump set up with a V/S blower for the home .With a seer of 15 or more. You can get a tax credit on that. Yes for sure more insulation and good vents in the attic. The cost there sounds high for the insulation . But they are different all over.
Id also get so the coil and compressor is a match set

;)