It ain't broke, but ....

I was dismayed to read ‘This Board is Closing’, since this is one of the few boards I follow now on TMF. Very happy to learn it was incorrect after all.

Our HVAC system (gas furnace, 12 SEER A/C) will be old enough to legally drink in less than 6 months (i.e., almost 21 years old). Total repairs over that time: zero (not including when rats ate through a wire, because that wasn’t the unit’s fault). Maintenance: Change the air filter regularly, clean the a/c coils every Spring.

We don’t use the a/c much (it may be on a dozen or two hours a year), so perhaps it’s no surprise that it’s lasted that long. We use the furnace a lot more, probably 100 hours or more each year.

Our local utility is offering big rebates to convert from a gas heater and a/c to a heat pump and air handler. Even with a 20 SEER a/c, I don’t see that changing our energy bill much (due to a lack of use, as mentioned above). But at current prices of gas & electricity, heating would cost about 50% less with an efficient heat pump. So we’d probably save perhaps $300? a year, combined.

As I see it, reasons to switch include:

  1. Factor in inflation, combined with the large rebates, and it will be significantly cheaper to change now rather than some unknown time in the future (as in, at least $5000, and likely much more as time goes on).
  2. An inverter heat pump with a variable speed air handler will be more comfortable (maintaining more even temps) than our current, one-stage gas furnace.
  3. Changing now may prevent being without a heater when it unexpectedly breaks and can’t be repaired or replaced for some unknown period of time. But …

Reasons not to switch include:

  1. New appliances just aren’t as reliable as old ones. Maybe a new unit is as likely to fail as our old one in not too many years.
  2. Replacing a working furnace and a/c seems very poor environmentally, and if they can keep working and working, just plain stupid.

Am I missing something? How likely is a major (>$1000) repair to be needed on a 20+ year old system that has been trouble-free up until now?

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What are the odds that your utility rebate program is ‘permanent’ and not a time-bound thing? Many times, those rebates are funded through a state-mandated environmental impact fee collected on your bill or some such thing, rather than simply as a program funded by the utility’s desire to put off capital investment in new generation capacity.

Rebate Programs funded through state mandates/additional charges are likely to stick around in one form or another, even if the specific details change. Ones funded purely through the utility’s desire to put off capital improvements (new generation capacity) are more likely to ebb and flow based on supply and demand forecasts.

We have a HVAC service technician come out and maintain our system 2x a year (once in the spring for the A/C, once in the fall for the furnace). Because of the maintenance agreement, we get priority service with no emergency after hours/weekend service surcharges for those rare occasions when something breaks… I think we’ve used that benefit once, when our furnace gave out the Saturday before Christmas one winter.

Two other things to consider when it comes to replacing a working system vs. waiting until an expensive-to-repair failure hits:

  1. it’s easier to shop around when it’s not sweltering hot or frigid cold in your home.

  2. what refrigerant is in your 21-year-old A/C system? If it’s old-school freon, I think that’s not allowed to be manufactured anymore. That lack of supply could make an otherwise simple repair/recharge prohibitively expensive or downright impossible.

Home Fool


Am I missing something? How likely is a major (>$1000) repair to be needed on a 20+ year old system that has been trouble-free up until now?

Until it needs that repair it would seem simple to just keep it from a pure $$$ standpoint.

If you have a gas furnace going to a heat pump is a change you might not enjoy, although new ones work great the “heat” put out by a gas furnace is much hotter at the register versus a heat pump. New Heat pumps are nice and do the job quite well but that change if you like warmth might not sit well. A gas furnace will put out around 120 degree air at the register while a new heat pump will put out 90 degree air at the register - it can go hotter but then you are not using the heat pump but heat strips and the efficiency is gone. Both will keep the house warm but the “feeling” of the warmer gas heat when it’s running is much different. Heat pumps tend to run a lot longer than gas so the circulation of the cooler air might not sit well with you.

The heat pump will be significantly less money per month to operate versus furnace a/c combo. I recently went from a 14 seer single stage 17 year old unit to 19 seer 5 stage heat pump and the monthly bills in the worst months where heat or cold is the worst (Jul/Aug) (Jan/Feb) it ran about 40% less. The more comfortable months are running 20-30% less. With my current run rate I’m saving $1,360 per year on my utility bill. The system will get less efficient with age however if the new system lasts 15 years and the savings is around $1,100 per year it will pay for itself in savings 100% as it cost $16k installed.

You have some decisions to make, take your time.


Since this board is in the Personal Finances category, I think it’s safe (yay!).

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What are the odds that your utility rebate program is ‘permanent’ and not a time-bound thing?
Great question. I will definitely look into that, because besides inflation (I’ve read HVAC prices are up about 30% in the last 2 years), that’s the major FOMO point.

We have a HVAC service technician come out and maintain our system
We lucked out, obviously in retrospect, by not signing up for an annual maintenance. If you assume about $60 per year, that’s a savings of over $1200. What I’ve heard is that the only real utility in what they do is check for dangerous conditions that might have developed since the last inspection. That, and the priority service, as you mentioned.

what refrigerant is in your 21-year-old A/C system?
Probably R-22, though I don’t know for sure. But since you brought that up, that might be a (minor) point in favor of waiting. California (where I live) has mandated that R410A (which almost all systems being sold now use) cannot be used in units sold starting this coming January. So buying a unit now ensures that we’ll be saddled with a situation similar to our current one, where the refrigerant becomes more and more expensive as time goes on. However, the systems need to be re-designed to use R32 or R454B, so who knows what problems might crop up with the early versions of such units.

If you have a gas furnace going to a heat pump is a change you might not enjoy,
Of course I can’t know until I actually experience it. But from what I’ve read, it might be the opposite. Gas furnaces do throw out hotter air, but that results in a larger, up/down cycle (especially as ours is a one-stage blower that is either full on, or off). So the room feels warmer than the set point (due to the hot air being blown right on us), only to cool down fairly quickly since when the blower stops, the warm air rises and therefore doesn’t circulate. With an inverter heat pump and variable speed blower, as you said, it runs a lot longer, mixing the room air better, lessening the temperature stratification in the room. (This is particularly relevant in our home, because it has 12-foot ceilings.) Since the air blower often runs very slowly, one might not even be aware it’s on, but it is, mixing the air. At least, that’s the theory I’ve read.

With my current run rate I’m saving $1,360 per year on my utility bill.
Wow. If our savings could be that big, I think it’d be a much easier decision. Our annual gas bills last year (air and water heating, and cooktop use) totaled < $700. It will likely be somewhat higher this year, as the price increased about mid-year, but still I just don’t see our savings going much over the amount I originally said. BUT, we do sacrifice a bit for that “low” bill, as we keep the thermostat at 65F during the day, 62F at night. We also usually shut it off during the day and let it drift down, since a gas furnace is so fast at raising the temp back up, which is something we wouldn’t do with a heat pump. Instead, I’d be tempted to just keep it at, say, 67F and never shut it off, hoping our expenditure would stay about the same, but we’d be much more comfortable. Yet, really, doing so would be a waste of money and resources. :frowning:

Thanks, guys; lots to think about.

The thermostat should control the swings. Whatever it is set to do, it should do. I don’t off-hand know how much swing triggers a thermostat, but that should be independent of the blower.

However, a variable-speed blower is much more energy efficient. We have that (gas heat, heat pump cooling). When it needs to blast, it blows hard. If not, it doesn’t. Though locally that is more evident when it cools (which is a heat pump, and actually has TWO compressors depending on the load demand).

I prefer the gas furnace. The only downside is that gas is a fossil fuel.


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When my 22 year old furnace and AC needed some repairs I chose to replace them since I knew Freon was no longer available for the AC. There were several rebates available at the time that I was able to use and also a 36 months at zero percent interest that I took advantage of. While I could have paid cash,I was happy to use their offer and paid it off after 34 months.

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Hi KenAtPcs,

Based on what you have said, you need to decide how much confidence you have in the system going forward.

At our old place, our heat pump was Ok for 7 years then our distribution transformer took a lightning strike and was replaced. Whole house surge protector saved everything in the house.

But, the replacement transformer was giving us 283-285 V. The solenoid and compressor fried a few days before Christmas. The closest parts were 7 days out. The outside unit could have been replaced but a compatible unit was not available and the newer generation units were not compatible with the inside unit.

In addition, the inside unit could not be properly tested without the other piece able to run. There may have been issues there to be discovered 7 days later.

But, they could get a new system and have it installed in just 3 days. Choice made …

You might talk with a service person about repair parts for your current system. Ours was an older-type system when installed and and lasted past a couple of newer generations being developed.

Without the high voltage, it would have lasted a lot longer. I learned a bit about replacement part availability over time and national distribution.

I would not count on rebates as a permanent thing.

With as little as you use it, if it did go out, I believe you should be able to wear a sweater for a few days or run a couple of fans as needed.

Let us know what you decide.

Does that help you?

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