The short answer
If both are over about 12 years old, do them together. Otherwise replace the one that failed.
Doing both at once means paying for the install labour once instead of twice, and it means the two halves are properly matched. Doing them separately spreads the cost, which matters if only one is actually old. The age gap between them is what decides it.
Side by side
Both sides, plainly, including what each one is bad at.
Replace both together
New heating and cooling in one visit, one set of labour.
- You pay for the install work once, not twice
- The two halves are matched, so the system performs as rated
- One warranty start date and one set of paperwork
- One day of disruption instead of two, a year apart
- A much bigger cheque today
- You may be throwing away a part that had years left in it
Replace one now
Fix the half that failed, deal with the other half later.
- Far less money today
- Right call when only one of them is genuinely old
- Keeps a perfectly good unit in service
- You pay for install labour twice over the two visits
- A new half paired with an old half can underperform
- The second one will pick its own moment to fail, probably a bad one
Which one is you?
Do both together if…
They are both past about 12 years old, or the failed one is expensive enough that you are already choosing between repair and replacement. If they went in on the same day and are now the same age, they will reach the end at roughly the same time.
Do one at a time if…
There is a real age gap — a 15-year-old furnace next to a 6-year-old AC, say. Replace the old one, keep the young one, and revisit in a few years. That is honest advice and it is often what we recommend.
Want to see the difference in real numbers?
We will price it both ways for your house — one now, or both together — so you can compare the totals yourself.
Get My Upfront Quote60 seconds online · or call (206) 486-6373
What each route costs
Typical industry ranges for Western Washington — not a quote. Your exact price comes upfront, before any work starts, and you approve it first.
Why homeowners hand it to us
- You approve the price first. Upfront quote before a single screw turns.
- Same-day service. Book in a minute, hear from a tech within 1 business hour.
- 500+ jobs done by 4.9★ rated, professional technicians.
- Fixed right, guaranteed. If it’s not right, we make it right.
Quick answers
How much do I save by doing both at once?
The saving is in the labour and the access, because the two units share a cabinet and much of the same work. It is not a small discount and it is not half price either. We will show you both totals side by side so you can judge it yourself.
Do the two halves have to match?
They should. A high-efficiency outdoor unit paired with a mismatched indoor coil will not deliver the performance it is rated for, and some warranties expect a matched pair. If you replace one now, we make sure what goes in will work with the other half later.
Should I get a heat pump instead of replacing both?
It is worth a serious look. A heat pump does both jobs from one system, so instead of buying a furnace and an AC you buy one machine. In our climate that works well for most homes.
My AC is fine but the furnace died. Do I have to do both?
No, and anyone insisting otherwise is selling. If the AC is young and working, keep it. We will replace the furnace with something that pairs properly with the AC you already own.
How long does replacing both take?
Usually one full day for a straightforward changeover. You are back to normal that evening in most cases.
Get both totals before you decide.
Book the visit. We price one now and both together, upfront, and the choice is yours.
Get My Upfront Quote60 seconds online · or call (206) 486-6373
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