Seasonal · August 8, 2026 · By Doug Kelley, Master Licensed HVAC Technician
Closing Up a Seasonal Home? The HVAC Winterization Checklist
The upper Shore is full of second places: watermen's cottages in Rock Hall, bay-front houses in Betterton, river places at Crystal Beach and along the Sassafras. Every fall they get closed up, and every spring a few of them open to expensive surprises: frozen pipe damage, mold blooms, systems that will not start. Most of it is preventable with an afternoon of care. Here is the checklist we give seasonal owners.
The core decision: heat on low, not off
Unless the house is fully winterized with plumbing drained, do not shut heat off entirely. Hold the house at 50 to 55 degrees: warm enough to protect pipes in walls and keep materials stable, cheap enough to barely register on the bill. A house at 40 with one cold snap and one uninsulated pipe run can generate a five-figure claim. The thermostat setting is the cheapest insurance in this entire article.
The closing checklist
- Fresh filter in, so the system breathes clean all winter at low runtime
- Heat tested under load before you leave, not assumed
- Thermostat verified at the holding setpoint, with fresh batteries if it takes them
- Water heater to vacation mode, or off with the tank drained for full winterization
- Mini-splits: clean the filters, and know that most will maintain a low heat setpoint reliably all winter
- Outdoor unit cleared of leaves and debris; do not wrap it in a full cover that traps moist salt air
- Someone local with a key and a reason to check after hard freezes and big storms
The upgrade that changes everything: remote eyes
A wifi thermostat converts a closed house from a hope into a monitored asset. You see the actual temperature from anywhere, get an alert the moment it falls below your floor, and can warm the house up the morning before you drive over. Freeze alerts have saved our customers real damage: a failing furnace announced by a falling graph gets fixed that week, instead of being discovered at Memorial Day through a smell. For waterfront properties, pair it with the salt-air habits from our coastal equipment guide; closed-up months are when salt does its quietest work.
Spring reopening, briefly
Opening is the reverse with additions: filter check, condensate drain check before the cooling season, a rinse of the outdoor coil, and a cooling test run on a mild day rather than the first hot weekend with the family arriving. We offer close-up and open-up visits for seasonal owners, timed to your calendar: (443) 310-0206.