Replacing Indoor A/C unit/Furnace

Cherokeekid88

Well-Known Member
Joined
Jun 30, 2007
Location
High Point, NC
OK, so here is the deal.
My current setup consists of a 28 year old indoor A/C / Heat Pump matched with a 5-6 year old Eanes outdoor unit.
We have had the fan motor replaced, capacitor, and had it serviced a couple of times.

The dilemma is, we are paying higher amounts for our bill than we ever have before but sweating in the process. We keep our A/C on 73 and its just too hot for us to be paying what we are paying. If we try and turn it down below that, it acts like it can't keep up.
While we were on vacation about a month ago, my in laws came to stay at our house and they said one day, the A/C would not go below 76...
I honestly feel that our A/C is cutting on and off too much and not cooling our house down.

My question is, can you just replace the indoor unit and leave the outdoor unit alone, since its newer? DO I have to replace the furnace along with the indoor A/C unit?

My ultimate goal is to have a system that can cool my 1500 sqft house during the summer and not cost us an arm and a leg.

I just need some guidance on this. The company that normally comes out to service my system just tells me that as long as my system is running, to leave it alone....
 
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The part outside is the business end of things.

It's either a furnace or a heat pump. More than likely, you have a heat pump with electric reheat strips.
 
Define an arm and a leg?

When it is 99 degrees outside the HVAC units most times are going to run all day and struggle to keep up.
Well, not trying to sell me the top of line unit when all I need is the middle of the line unit. I know its been hot, but the last 3 years have also been hot and I have never had my bill this high or my A/C run and cut off as much as it has lately.
Just a hard pill for me to swallow when I am staying hot at night in my house to try and keep the A/C from over load and still paying out the wazoo. Just doesn't add up to me. something is up.
 
Damn 73 degrees and not comfortable? Mine is set for 74 with two units we used 2300 kwh last cycle for the house. Equalled 309 for our electric bill.
 
Well, not trying to sell me the top of line unit when all I need is the middle of the line unit. I know its been hot, but the last 3 years have also been hot and I have never had my bill this high or my A/C run and cut off as much as it has lately.
Just a hard pill for me to swallow when I am staying hot at night in my house to try and keep the A/C from over load and still paying out the wazoo. Just doesn't add up to me. something is up.

How much is your AC bill a month?
 
Damn 73 degrees and not comfortable? Mine is set for 74 with two units we used 2300 kwh last cycle for the house. Equalled 309 for our electric bill.
73 and not comfortable....hell no. but I must also note that we only have single zone heating/cooling. but I remember last year, keeping it on 71 most of the time and our bill not being this much during July and August.
Current bill is $300. highest it has ever been was $184 which was last year.
 
Attic insulation is where it's at. I blew 13" through out my attic (1700 sqft) and saved over 100$ month during the summer. My A/C stays on 73* Also windows as said, replaced with double pane and saved even more. My highest bill this year has been 145$ Ceiling fan in every room. and a 4 x 5 window facing west used to cook the front room until I replace it & insulated attic.
 
How well is the house insulated? Windows old and single pane? Do you have blinds to keep sun out? Ceiling fans for circulation?
The house seems to be pretty well insulated. I could be wrong, but we did just install a new back door, front door, and garage entry door and made sure it was all insulated and sealed.
Windows are the ones that came with the house, I'm guessing. We have been keeping the blinds closed and even party closed with curtains. No ceiling fan downstairs, but one upstairs...if we didn't have that ceiling fan upstairs, we both would probably have suffocated by now.
When was the last time you changed the filter?
I have been very good about changing the filters... I change them every month. last time I changed one was about 3 weeks ago.
 
Does the air volume coming out of the diffusers feel "right"?

If your bill went from $185 last year to $310 this year, I'd suspect that something has gone wrong. Like, a duct has come loose from the trunk, there's a whole-system filter that you didn't know about, etc.
 
Does the air volume coming out of the diffusers feel "right"?

If your bill went from $185 last year to $310 this year, I'd suspect that something has gone wrong. Like, a duct has come loose from the trunk, there's a whole-system filter that you didn't know about, etc.
that's the thing.. I never really paid attention until now.. I mean it feels ok I guess. I am a total newb when it comes to A/C stuff.

but I agree, something is just not right. Most people are saying "well its been hot this year" Well, its been hot every year and it just seems something is not kosher.
 
Does the air volume coming out of the diffusers feel "right"?

If your bill went from $185 last year to $310 this year, I'd suspect that something has gone wrong. Like, a duct has come loose from the trunk, there's a whole-system filter that you didn't know about, etc.
^^ this. I'd also verify that you have appropriate attic insulation. Maybe look into installing a powered attic fan. I had a similar issue earlier this summer. Installed a blower fan on a gable and a exhaust fan near the ridge. Hasn't cut the bill by much, but my inside temp isn't creeping up on hot afternoons. So hopefully it'll pay of by not overworking my hvac.
 
To be fair, this summer has been appreciably hotter than the last 2.
However not 185->310 hotter.
The unknowns you haven't shared are has your utility had a rate increase (*I bet they have) where every kwh costs more than it did last summer.

I also seem to remember you getting a lot of advice not to replace a set of french doors with a sliding glass door because they were much less efficient and you basiclaly saying you werent concerned about increased energy costs you wanted a sliding glass door.Congrats you have one :) Sorry had to be that guy.

That aside I would also wonder if you dont have a major component failure. I was thinking along the same lines as Shawn about a duct coming loose but you said it cycles more frequently. A loose duct if anything would cause longer run cycles.
Have you replaced your thermostat recently?
You arent trying one of the programmable jobbers and turning it off while you are gone are you?

Do you have a competent HVAC guy? Has he checked the freon level and the cooling temp performance?
 
To be fair, this summer has been appreciably hotter than the last 2.
However not 185->310 hotter.
The unknowns you haven't shared are has your utility had a rate increase (*I bet they have) where every kwh costs more than it did last summer.

I also seem to remember you getting a lot of advice not to replace a set of french doors with a sliding glass door because they were much less efficient and you basiclaly saying you werent concerned about increased energy costs you wanted a sliding glass door.Congrats you have one :) Sorry had to be that guy.

That aside I would also wonder if you dont have a major component failure. I was thinking along the same lines as Shawn about a duct coming loose but you said it cycles more frequently. A loose duct if anything would cause longer run cycles.
Have you replaced your thermostat recently?
You arent trying one of the programmable jobbers and turning it off while you are gone are you?

Do you have a competent HVAC guy? Has he checked the freon level and the cooling temp performance?
Basically my unit is running for about 5-7 minutes and then is off for another 5-7 minutes and then running for 5-7 minutes. This is even when we have had those slightly cooler mornings when it feels about the same outside as it does in my house.
T stat has yet to be replaced...don't know how old the current one is, but didn't just want to throw $50 at a new one if that wasn't the case.
The t stat I currently have in a Honeywell digital t stat, nothing special. I leave it on the same temp all day long (as of 3 days ago, that would be 74 degrees)
We have J&W heating and Air (referred to us by a family member) and they seem to have done us right the last couple times we have called them. competent? not so sure... they kind have that slingblade thing going on it seems.

My condensation line was clogged a couple weeks ago and this is the seconds time the unit as leaked water all over our hardwood floors...cut the condensation line and cleaned it out, (clogged up pretty bad) and made sure the line outside was draining properly.
 
Sounds like it's short cycling. I'm back to a clogged filter, low freon, etc.
 
Something is seriously fawked with you system if you are paying $311 for 1,500 sqft. You would faint if I told you my electric bill.

The company that normally comes out to service my system just tells me that as long as my system is running, to leave it alone....

Hire someone else.
 
By any chance are the heat strips coming on? The bill would be higher if they did but who knows. My coop has it setup online I can compare last year's bill to the current one.
 
Basically my unit is running for about 5-7 minutes and then is off for another 5-7 minutes and then running for 5-7 minutes. This is even when we have had those slightly cooler mornings when it feels about the same outside as it does in my house.
T stat has yet to be replaced...don't know how old the current one is, but didn't just want to throw $50 at a new one if that wasn't the case.
The t stat I currently have in a Honeywell digital t stat, nothing special. I leave it on the same temp all day long (as of 3 days ago, that would be 74 degrees)
We have J&W heating and Air (referred to us by a family member) and they seem to have done us right the last couple times we have called them. competent? not so sure... they kind have that slingblade thing going on it seems.

My condensation line was clogged a couple weeks ago and this is the seconds time the unit as leaked water all over our hardwood floors...cut the condensation line and cleaned it out, (clogged up pretty bad) and made sure the line outside was draining properly.


Is it still doing the 5 minutes on/off/on thing since the condensate line was cleaned out? If not that could have been the problem. Its very common to break the air handler contacts through either a moisture switch or a sump pump switch (if your condensate drain uses a pump-mine does)...potentially it could have been a -> run->produce condensate->shut down because of condensate build up->drain down->restart-> repeat cycle. In which case it would never run long enough to be efficient.

Like Shawn said that is referred to as short cycling. Something is causing that. That will run your power bill up.

I'm guessing the only thing indoor is the air handler and the coil. (But I am just guessing because 30 years ago...I mean lots of stuff is possible) That's not typically going to be a power sink. Basically it is a big box with a cold radiator in it and a fan that blows air across that cold radiator and out into your ducts. If it fails, its usually the blower motor and they typically fail off. Is it feasible you have an internal winding random short? Yes, I suppose. But highly unlikely. You could even replace that motor for a newer more efficient one, but again that isnt going to cause the cycling you are seeing.
 
Does your tstat stay on what ever you set it to or does temp slow rise through out the day?

If unit is shot cycling like it sounds it is, it will not pull the humidty out of house. 73* with high humidty is alot less comfortable then the same 73* with a low humidity %.

The float switch as Ron said could definitely be the cause if drain was filling up shutting unit down until drain was able to slowly empty back out.
 
If it's cycling 5 on 5 off its not running correctly. Find another hvac company. I think 5-7 minutes is the cycle time for the newer thermostats. If you have one of those, it sounds like the system is overloading or getting switched off, then coming back on after the reset time. Have you watched the temp on the thermostat while it cycles. Does the temp drop then system kicks off? Turn it down to 65, of its still going, 5 on 5 off, you got a problem. Where are you located?


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Have both condenser and evaporater coils checked and have them cleaned thoroughly. A filthy restricted evaporater coil will cause it to work way harder than it needs to.
 
And by the way you cannot just change air handler / inside unit. your system uses the old refrigerant, Possibly r12 or r22 they are banned and stupid expensive, possibly more expensive than the inside unit. New refrigerant uses a much higher pressure and is more efficient. My mother just ran into a similar issue with one of units on her house. Compressor went out, cost of compressor and new charge of the banned r22 was about the same as a complete system upgrade.


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