2 Stage runs constantly

[MrShamrock]

I had a new 2 stage heat pump installed a few years ago and have just been letting it run on the settings that the guy who installed it left it on. Now that it is getting cold again I need to find an answer to this question. For the record I don't know a thing about HVAC so please excuse me if I don't word this right. Anyway, I have a 2 stage system that seems to run non-stop. I understand that the 1st stage doesn't use near the electricity as the 2nd stage, but I don't understand why it needs to run all the time. If I set the t-stat at say 72 it usually will get the house up to 70 and then just run in the first stage. I tried bumping the temp up to see if my system was able to increase the temp more and it does - I put it on 76 and it gets to 74 and runs and runs. I have played around with the deadband setting which, from what I understand has something to do with the degree difference from 1st to 2nd stage (please correct me if I am wrong). What is frustrating is my father lives right across the street and his house is 500ft² more than mine, but his electric bill is lower AND I have brand new double pane windows and he still has the old single panes AND his HVAC system is probably 7 years older than mine. His is not a 2 stage system (i don't think) because he just has an "old school" lever type t-stat. He does have a NG water heater vs. my electric so that may be the big difference though.
Should I change to a different t-stat that doesn't have all these settings? Any other idea's? Thanks in advance!

[HVAC/Stud]

Have the install contractor do a service call to check charge and setting on tstat. Ask him what the balance point is and if he did a Manual J, to size the system. Ask him to explain the second stage elect heat, and make sure its working right. If he has the deer in the headlight look, call a NATE cert tech.

STUD

[MrShamrock]

Is there nothing I can check myself. I joined here to try and avoid calling a shop if it is something simple like a t-stat setting.

[kls-ccc]

The point of multi-stage equipment is to better match the size of the equipment to the needs of the house. This helps keep utility bills low and the house more comfortable. The other benifit of this is a slower fan speed is quieter. It sounds like the equipment is sized ok as it can raise the temp in the house. If the system is noisy there may be some duct issues that need to be addressed.

[MrShamrock]

No the system isn't noisy at all. I am just concerned about it running for 80% of the day.

[second opinion]

No the system isn't noisy at all. I am just concerned about it running for 80% of the day.

If it is running in first stage and when temperature is increased at Tstat and room temp increases, I would not be concerned.

Your house is going to have a loss and the unit is maintaining that loss to give you a constant comfort level.

[jpsmith1cm]

mtrot,

This is the Ask Our Pro's forum. In order to post advice here, you must have verified qualifications and have been approved by the AOP Committee.

You can find the rules for posting and qualifications here (http://hvac-talk.com/vbb/showthread.php?t=957002).

[beenthere]

What brand and model number is your thermostat.

[beenthere]

JakRabbit.

This is the Ask Our Pro's forum. In order to post advice here, you must have verified qualifications and have been approved by the AOP Committee.

You can find the rules for posting and qualifications here (http://hvac-talk.com/vbb/showthread.php?t=957002).

[MrShamrock]

What brand and model number is your thermostat.

Kenmore TR7DRHI

[platchford]

How much lower is his electric bill. How many people does he have living in his house compared to you in your house? Do you both have the same type of dryer (electric or nat gas) and the same type of range/stove? I assume he has a heat pump as well and not a nat gas furnace.

[beenthere]

Not familiar with that thermostat.

You'd probably like a Honeywell IAQ thermostat better.

[MrShamrock]

How much lower is his electric bill. How many people does he have living in his house compared to you in your house? Do you both have the same type of dryer (electric or nat gas) and the same type of range/stove? I assume he has a heat pump as well and not a nat gas furnace.

It seems his averages about $40 less than mine. He has 3 people and I only have 2. What gets me is my step mom is very cold natured so they keep it in the upper 70's while ours hardly ever gets set over 72 - it is usually set to 65 during the day and 70 at night. They are both retired and are home all day running the heat too. Both of our appliances are electric with the exception of he has an on demand NG water heater where mine is an electric tank water heater (I plan on adding an on demand NG water heater soon though). I just would think with our house being more "up to date" with double pane windows and sliding glass door, new front door (where his is old and leaks so much he has tape running around the seam and makes everyone come in through the garage), all my appliances are fairly new, plus the above listed differences our bill should be less. Unless the hot water heater is the difference. I know after a long days work I do enjoy a long hot shower.
I did find my manual for my t-stat and reprogrammed my dead band to 6 and the heat has been off for the last 15 minutes or so. This is the longest it has been off that I can remember. The deadband was on 2 so maybe that was hurting me some. I was recommended to put it at 6 and see how comfortable the house is and bump it down if needed.

[SBKold]

Is that thermostat the one that your hvac company installed with the new unit?

[MrShamrock]

Is that thermostat the one that your hvac company installed with the new unit?

Yes it is.

[beenthere]

Don't set your temp low, and then raise it up. that brings on the strip heaters when you set the temp back up, and raises your heating bill. Set it and forget it.

[MrShamrock]

I think I am on to something with the deadband setting. It hasn't come on for over 30 minutes = new record!!! It has dropped a few degrees but is still comfortable.

[MrShamrock]

Don't set your temp low, and then raise it up. that brings on the strip heaters when you set the temp back up, and raises your heating bill. Set it and forget it.

That makes sense now with the deadband adjusted. I just couldn't see the heat running all day while I am gone. Now if it comes on once every hour I can see just setting it and forgetting about it.

Is it better to allow the temp to drop the 6 degree's like it will now before the 1st stage comes on or decrease that a bit? I have a read a few threads where a setting of 4 is recommended or is this a house by house basis??
Also with a higher deadband should the setpoint be bumped a little higher so it doesn't get quite so cold between cycles?

[beenthere]

A higher dead band, just makes it run longer to get back up to temp. And setting the temp higher because of the higher deadband, just uses more electric.

[MrShamrock]

So what is the "sweet spot"? My wife just said she was cold so I moved the deadband to 4 and set the temp to 72. What is the lesser of the 2 evils - low deadband and system running constantly or high deadband and system coming on less, but running longer when it does come on? This is too confusing! I miss Florida - set the A/C to 70 and never touch it.

[beenthere]

A good thermostat. Honeywell IAQ. You can't set the deadband. But it will go to second stage when it determines that first stage is at 90% of system capacity. So it won't run as long as your system currently does. You can also set it to time to second stage.

[MrShamrock]

Thats what I need! Thanks man. Time to go shopping!

[MrShamrock]

Wow Honeywell is proud of them things!!!!

[platchford]

It's possible that the existing thermostat isn't really designed for a setback (dropping the temp when you are asleep or home) and when the program requires the temp to go back up the strip heaters are kicking in and killing any savings by setting the temp back as well as actually causing an increase in electric usage.

The aforementioned Honeywell stat will bring the heat pump back on in advance of the programmed time so that the electric heat isn't utilized as much. Generally speaking though you don't want to set a heat pump system back too much as recovery is much harder for those.

Now a question. If you have natural gas available (as evidenced by you considering a nat gas tankless water heater) then WHY did you install a heat pump with electric strip heaters? Why not a straight AC with gas furnace or heat pump with gas furnace?

[MrShamrock]

When I installed this system NG was not available on my street. They would only connect me if I was switching all my major appliances to NG. I had just bought all new electric appliances so that was out of the question. Just last year me and my dad (who is right across the street from me) just happened to talk to the right guy and they came out and hooked us up because he agreed to do the tankless water heater. I am currently only using it for a set of gas logs in the fireplace and 2 heaters in my garage. When we bought this house it had an oil burning furnace which I loved the heat it put out and how quiet it was, but the 300-400 per month bill quickly made me run to electric. Plus the A/C and heat unit were from 1981 so it was due for an upgrade.

[platchford]

I might consider replacing the air handler with a furnace and coil and having the advantage of a dual-fuel heat pump system. This would depend on a number of factors such as the cost of nat gas vs electric in your area and how often the heat needs to run (based on heat loss) which is largely a function of where you live. Of course, it also depends on the cost to do so vs the savings gained by doing so... return on investment.

[catmanacman]

it is also possible that your unit is not performing properly and not putting out the btu,s it should I would have it checked.

[MrShamrock]

Just a little update. With the deadband moved to 4 it is performing like I think it is supposed to. It seems to be just as comfortable and it isn't running near ar much. I guess the true test is when the bill comes.