Mini-Split Mold & Odor Removal in Plymouth, NH

A Plymouth tenant complaining that the mini-split smells like old socks when it starts is describing mold on the blower wheel. We take the mini-split apart, flush and treat it, clear the drain, and hand you a record for the unit.

Local Knowledge

Mini-Split Mold & Odor Removal in Plymouth

Electric utility: NH Electric Co-op · Grafton County

The smelly mini-splits in Plymouth are mostly in rentals, and the reason is simple: they run more and get cleaned less than any other mini-splits in the region. A student apartment above Main Street uses the mini-split as the only heat all winter, then runs it on cool through a humid June with the window open and the coil wet. Nobody washes the filter, nobody opens the cover, and the growth on the wheel gets a full year of mini-split start before the landlord hears about it.

The river blocks make it worse. Apartments and houses near the Pemi River Walk and down where the Baker joins the Pemigewasset sit in summer fog, and a first-floor mini-split there runs wet for hours a day. Older pre-war houses with damp stone cellars and a mini-split on the first floor get the same musty smell every August.

It shows up in the year-round neighborhoods too, just later. A mini-split out Tenney Mountain Highway or off Route 3 that runs in dry mode all summer and is shut off wet at night develops the same sour smell and black specks by its fourth or fifth season, which for most of the 2019 to 2024 NH Electric Co-op rebate installs is right about now.

Plymouth Tip

Plymouth landlords who get a smell complaint in August should treat the mini-split before the new tenant moves in, not after. A treated, drained mini-split at move-in prevents the complaint from being the first thing a new tenant learns about the apartment.

What we treat, and why the drain is half the fix

The mini-split comes apart on the wall with a bib bag under it. Coil and blower wheel are flushed until the runoff is clear, then an HVAC-rated antimicrobial is applied to the coil, the wheel and the pan, dwells, and is rinsed. The pan is scrubbed to bare plastic. Then the condensate line is cleared end to end and tested with water, because a slow drain leaves a puddle in the pan and the puddle is where the smell restarts within a couple of weeks.

In a downtown Plymouth building we follow that line to its outlet. Lines that end in a shared gutter, over a sidewalk or into a cellar back up in humid weather and keep the pan wet. Filters, louvers and the cover are washed, the mini-split is reassembled and run on cool with the door shut until the room smells like nothing. For a rental we leave a note on the unit record so the next tenant knows the mini-split was treated and when.

The Plymouth mini-split that smells like a dorm fridge is $199 — growth removed, pan cleared, antimicrobial treatment on. Each additional affected unit is $119. Two on one compressor is $318, and the worse one is not priced above the better one.

  • Antimicrobial applied to wheel, coil and pan
  • Condensate line cleared and water-tested
  • Drain outlet checked on downtown and river-side buildings
  • Student-unit mini-splits that have never been opened
  • Run-and-sniff test with the door closed
  • Unit record noted for the next tenant
Straight Answers

Common Questions in Plymouth

My tenant says the mini-split smells. Is that a cleaning or a repair?

Almost always a cleaning. A smell at start-up, a sour or dirty-sock odor, or black specks on the louvers all mean growth on the blower wheel and coil, not a failed part. A teardown with an antimicrobial treatment and a clear drain fixes it. If we find a real fault, we tell you before doing anything.

Why do the river-side apartments smell worse in summer?

Fog off the Pemi and the Baker keeps the air on those blocks wet from June into September, and a mini-split cooling a first-floor room pulls that water onto the coil all day. A wet wheel grows things fast. Up the hill the air is drier and the same mini-split takes another year or two to get there.

Will the treatment bother a tenant with allergies?

No. The antimicrobial is rated for HVAC coils, is rinsed after it dwells, and leaves no scent when the mini-split runs afterward. The treatment removes the thing that was bothering them, which is the mold and dust blowing off the wheel. The air coming out afterward is just air.

Need Mini-Split Mold & Odor Removal in Plymouth?

Per-mini-split prices you can see before you call, a bib-bag teardown that leaves nothing on your wall, and scheduling that fits a Lakes Region calendar.

Request a Free Quote

Tell us the town, how many indoor mini-splits and outdoor compressors you have, and what you're noticing. The price is $199 for the first mini-split and $119 for each additional — we'll confirm the total and a date.

We reply to every request within 1 business day.

  • Free quote — no obligation
  • $199 first mini-split, $119 each additional — published up front
  • Bib-bag teardown — nothing on your wall or floor
  • Every mini-split run and tested before we leave
Free Quote