Stop guessing whether your generator will start the AC.
One unit covers condensers and heat pumps from 1 to 6 tons. It ramps the compressor instead of slamming it, and a Bluetooth app shows your before/after start current on your phone — so you see the proof, not a spec sheet.
$399.00 on Amazon price checked 2026-06-11 · Amazon is the seller; price can change
#ad — affiliate link. As an Amazon Associate I earn from qualifying purchases, at no extra cost to you.
This is probably why you're here
- Your generator runs the house but stalls when the AC kicks in.
- The lights dip every time the condenser starts.
- You want to actually see your start current drop, not trust a spec sheet.
- You're prepping for hurricane season and the AC is the weak link.
Verified specs
| Model | EasyStart Flex 398 — Amazon kit listing "398 KIT", sold with installation kit |
| Capacity | 1–6 ton single-phase AC & heat pumps (up to 72,000 BTU) |
| Voltage | 100–250 VAC, 50/60 Hz |
| Start-current reduction | Manufacturer-rated up to 75% |
| Monitoring | Bluetooth app (iOS / Android) — live start-current readout, fault codes |
| Safety listing | UL-listed add-on accessory (per manufacturer) |
| Warranty | 2-year manufacturer warranty |
| Made in | USA (Hamilton, NJ) |
Specs from the manufacturer's published product page and specification sheet. Always confirm fit against your condenser's data plate (RLA/LRA) before purchase — or ask us below and we'll check it for you.
The surge it removes
The whole job happens in the first fraction of a second after the compressor energizes — and the Flex's app puts this exact before/after on your phone:
What it does not do
It won't meaningfully cut your running power bill, won't rescue a failing compressor, and isn't needed on variable-speed/inverter condensers (they already ramp). The "extends compressor life" claim is debated in the trade — we don't sell it on that.
Good fit
- 1–6 ton single-phase residential AC / heat pumps
- Generator or solar/battery startup problems
- Flicker on every compressor start
- You want app-measured proof, not a brochure number
Skip it if
- You have a variable-speed / inverter condenser
- The compressor is already failing
- You want a run-time efficiency gain
- Three-phase or commercial equipment
EasyStart Flex vs. SureStart
Both are true ramped soft starters with comparable measured surge reduction. The Flex costs about $140 more and adds the Bluetooth app — live current readout and fault codes. The SureStart is a sealed box sized per model by your compressor's FLA, nothing to pair. Want the app → Flex. Set-and-forget → SureStart.
Will this void my AC warranty?
Common fear, few documented cases. Your protection: have a licensed HVAC contractor install it and keep the receipt. Our full write-up →
Which model do I need for my unit?
For 1–6 ton single-phase residential units, the Flex is Micro-Air's one-size answer (that's the point of it). Send a photo of your condenser data plate with the form below and we'll confirm fit before you spend anything.
What it costs to own
- Hardware
- $399.00 on Amazon (checked 2026-06-11; price can change)
- Install
- Licensed HVAC contractor / electrician — typically under an hour
- Consumables
- None
- App / extras
- Bluetooth app included; no subscription
Don't have an installer?
I might know someone in your area I trust. Tell me where you are and I'll see who I've got — I review every request by hand, and if I don't have anyone good near you, I'll say so.
Check if the EasyStart Flex fits your unit
Send your condenser details and we'll confirm fit before you spend anything — including telling you if you don't need a soft starter at all. A real person reads every one — no spam, no selling your info. Prefer to talk? Call or text (813) 668-8856.