Winter Piano Care: How to Protect Your Piano From Dry Indoor Air

Short answer: In winter, heating dries the air indoors, and the wood and felt in an acoustic piano shrink as they lose moisture. That can knock the piano out of tune and, over time, lead to cracks. Keep humidity steady, keep the piano away from heat sources and windows, have it tuned at least twice a year, and clean it gently.

This checklist is for families with a piano a child practises on, and for adults who own an upright or grand. There's a short section for digital piano owners too. None of it takes special tools or skills. It's mostly small habits that mean fewer surprises when the heat comes on.

This is general guidance, not professional advice for your instrument. Follow your piano maker's and humidifier maker's instructions, and for repairs or anything inside the piano, ask a piano technician, such as a Registered Piano Technician (RPT).

Why winter is hard on pianos

An acoustic piano is mostly wood, felt and metal under tension. The Piano Technicians Guild explains that in most areas, relative humidity is very low during the cold winter season. When the air dries out, the piano's wooden soundboard shrinks and loses some of its gentle upward curve. That eases the pressure on the strings, so the pitch drops, most noticeably in the middle of the keyboard. When humidity rises again in spring, the soundboard swells and the pitch moves back up, although individual strings end up slightly off from where they were.

Yamaha goes further: it calls excessive dryness an even more serious problem than too much humidity, especially where heating creates artificially dry rooms. Very dry air makes wooden and felt parts shrink, which can cause noises and loosen the tuning pins. In extreme cases, the soundboard and glued joints can even come apart.

The good news is that you don't need a perfect room. You need a steady one. The Piano Technicians Guild says keeping the humidity around your piano as constant as possible helps it stay in tune longer and slows damage like soundboard cracks, loose tuning pins and failed glue joints.

Your winter piano checklist

When the heat first comes on

1. Put a hygrometer near the piano. A simple wall or tabletop hygrometer shows the room's relative humidity. The Piano Technicians Guild suggests one as an easy way to keep an eye on changes. Place it near the piano, not right beside a humidifier, so it reads the air the piano actually sits in.
2. Check where the piano sits. Look for heating vents, radiators, baseboard heaters, a fireplace, drafty windows or an outside door nearby. See where to put a piano in winter below.
3. Listen and make a note. Play a few familiar pieces and jot down anything odd: notes that sound sour, keys that feel slow, a new buzz. It gives you a baseline, and a technician will find it useful later.
4. Clear the top of the piano. Move plants, drinks and anything else that could spill. More on family habits below.

Through the winter

1. Keep humidity steady. Check the hygrometer every few days, and more often during cold spells or right after you change the heating.
2. Run a room humidifier sensibly, if you need one. The Piano Technicians Guild says a room humidifier during dry seasons will help "somewhat". Keep it away from the piano: Steinway advises that a piano shouldn't be in direct proximity to a humidifier. Don't point the mist at the piano, never put a humidifier under or on it, and keep its cord and water away from outlets and electronics, including a digital piano. Clean and refill it as its manufacturer's instructions say. If it's an ultrasonic or cool-mist type, use distilled or demineralized water, because minerals in tap water can come out as a fine white dust that settles on nearby furniture, including the piano.
3. Watch the windows. The Piano Technicians Guild warns that too much moisture added to a room in winter can cause condensation on cold surfaces such as windows. Water on the inside of the glass is a sign to turn the humidifier down. In very cold weather, windows can fog even when the room is still below the piano's ideal range, so go by the hygrometer: a steady level a little under 40 percent is better than one that keeps swinging. If you can't get close without wet windows, ask your technician about an in-piano humidity control system.
4. Avoid sudden warm-ups. Yamaha notes that when a cold room is warmed suddenly, moisture can condense on the strings and other metal parts. If the piano room is kept cool, warm it gradually rather than blasting the heat.
5. Close the lid after playing. A closed lid keeps dust out and spills off the keys.

In early spring

1. Expect another change. As the heating goes off and humidity rises, the soundboard swells again and the pitch moves. This is another natural time for a tuning.
2. Turn the humidifier down or off as the air gets more humid, and keep watching the hygrometer.

What humidity should a piano be kept at?

Piano makers and technicians don't all give the same number, but they're close:

All three overlap at roughly 40 to 45 percent, so that's a sensible target. But steady matters more than exact. A piano that sits at a consistent level all winter generally fares better than one that swings up and down every few days as a humidifier runs out and gets refilled.

If your home is hard to keep steady (a very open layout, high ceilings or a poorly insulated older house), ask a technician about a humidity control system installed inside the piano. The Piano Technicians Guild describes these systems as a humidifier, a dehumidifier and a control unit that senses the humidity inside the piano and adds or removes moisture as needed, designed to keep it at 42%. They're installed by a technician and still need some upkeep. If your piano is under warranty, check with the maker or dealer first. Please don't improvise your own version, like a container of water inside the piano.

Where to put a piano in winter

The Piano Technicians Guild's advice is simple. Keep the piano away from places where it's exposed to extremes of temperature and humidity:

• Heating and cooling vents, radiators and baseboard heaters
• Stoves and fireplaces
• Doors and windows, especially ones that are opened often or are drafty
• Direct sunlight, which the Guild calls especially damaging

If your home isn't well insulated, an interior wall is better than an outside wall. If the piano can't move, a simple vent deflector that sends warm air away from it can help. Moving an acoustic piano, even across a room, is a job for professional piano movers, not a family weekend project.

How often should a piano be tuned (and when in winter)?

At least twice a year for most home pianos. The Piano Technicians Guild says that while manufacturers' recommendations vary, they generally agree a piano should be tuned at least two to four times each year. Yamaha says the strings need to be tuned a minimum of twice a year. Steinway says tunings should be scheduled at a minimum of six-month intervals.

More often for some pianos:

• New pianos. The Piano Technicians Guild's servicing page lists manufacturer guidance of more tunings in a new piano's first year while the strings stretch and the wood settles, then regular tunings after that (the makers quoted range from at least once to at least twice a year).
• Pianos that get a lot of use, like a teacher's studio piano. The Guild notes that constant use tends to wear a tuning down more quickly.
• Homes with big seasonal humidity swings. The Guild calls humidity variation generally the most important factor in how often a piano needs tuning.

When to book in winter. A tuning done just as the heat comes on may not hold, because the piano is still adjusting to the drier air. It usually makes sense to book once the heating has been running for a while and the piano has settled, and to ask your technician what timing they recommend for your home. If you keep humidity steady, each tuning has a better chance of lasting.

New piano this winter? A piano needs time to settle into a new home. Our guides to piano stores in Canada and piano stores in the USA cover tuning after delivery and what to ask the store before you buy.

Cleaning your piano at home (what's safe)

Keys

• Everyday: wipe the keys with a soft, dry cloth, as Yamaha recommends.
• For grime: use a soft cloth dampened with water and a little mild soap, then wrung out thoroughly. The Piano Technicians Guild suggests wiping back to front rather than side to side, so moisture and dirt don't seep down between the keys, and doing a few keys at a time, drying them straight away with a clean cloth.
• Black keys: clean them the same way but with a separate cloth, so black marks don't end up on the white keys.
• Never use cleaners that contain alcohol. Yamaha warns that they can crack the keys. The Guild also says to avoid solvents.
• Older pianos with ivory keys need extra care. Ivory is porous, and too much moisture can loosen the glue. Keep the cloth barely damp, or ask your technician.

Case and finish

• Dust with a soft cloth or feather duster. The Piano Technicians Guild says to remove dust first, so you don't drag grit across the finish.
• Skip household sprays. The Guild advises avoiding aerosol products and anything containing silicone, and using polish sparingly, if at all. Yamaha also lists aerosols and paint thinner or petroleum-based products among things to keep off the piano.
• Use a different cloth for the case than the one you used on the keys.

Inside the piano

Leave it alone. The Piano Technicians Guild says the delicate parts inside should be cleaned only by your technician, and to avoid touching the strings with fingers or damp cloths. That means no vacuuming inside, no reaching in to fix a sticky hammer, and no lubricant sprays. If something has fallen inside, mention it at your next tuning or call a technician.

Family rules

A few house rules go a long way, especially with young players:

• Wash hands before playing. The Guild recommends it to keep the keys clean, and Yamaha calls never playing with dirty hands "a good habit to cultivate".
• No drinks, vases or plants on the piano. Spills and condensation can cause serious damage. Yamaha suggests keeping nothing on the piano except sheet music or a metronome.
• Close the lid when you're done.
• No stickers, toys or crayons on or inside the piano. Small objects can end up under the keys.

Warning signs and what to do

Not every winter change is a problem, but these are worth noticing:

A soundboard crack sounds scary, but it isn't always serious. Let a technician decide. What matters most is that you don't try to fix anything inside the piano yourself.

When to call a technician

Call a piano technician when:

• It's time for a regular tuning, or the piano has gone noticeably out of tune
• Keys, pedals or noises don't improve once humidity has been steady for a while
• You see a crack, or something has spilled or fallen into the piano
• You're thinking about an in-piano humidity control system

The Piano Technicians Guild certifies Registered Piano Technicians (RPTs), which is one way to find a credentialed tuner. Many piano stores also offer tuning and service. Our tuning and service page (currently one listing, in Dallas, Texas) and our guides to piano stores in Canada and piano stores in the USA, which compare stores on tuning and service among other things, can help. We don't vet or endorse service providers, so check credentials and reviews; a local search or a piano teacher's suggestion can help too.

Digital pianos and keyboards in winter

Digital pianos don't need tuning (see our guide to choosing a digital piano keyboard for why). They still need a little winter care:

• Keep it away from heaters. Yamaha's owner's manual for its P-145 digital piano warns against exposing the instrument to extreme cold or heat, such as direct sunlight, a spot near a heater or a car during the day.
• Let it warm up after a cold trip. If a keyboard has been in a cold car, garage or storage room, let it come up to room temperature before you switch it on. The same condensation Yamaha warns about for acoustic pianos can form on cold surfaces when they meet warm, moist air, and electronics don't like moisture.
• Use a dust cover, and clean it with a soft, dry or slightly damp cloth. The same Yamaha manual says not to use paint thinners, solvents, alcohol or cleaning fluids, and warns against using the instrument near water or in damp conditions, so keep drinks and humidifiers away from it.

Keep playing all winter

Winter is a great time to build a steady practice routine. Short, regular sessions beat long, rare ones; our guide to how long to practise piano every day has ideas by age and level. For something seasonal, try our easy Christmas piano songs. For first-year players, our store carries Bastien's Christmas Classics, Primer A.

Ready for winter

Keep humidity steady, keep the piano away from heat and drafts, book a tuning once the heat has been on for a while, and clean it gently. That covers most of what a home piano needs from November to spring.

• Need a tuner? See our tuning and service page (one listing so far, in Dallas) and our stores guides for Canada and the USA.
• Want lessons this winter? Send a lesson request. It's free. It's free for students, and we'll pass your request to independent teachers who may fit.

Piano teacher? Your studio piano works harder than most, and families notice a well-tuned instrument. List your studio on The Best Piano Teachers.

What's your winter piano routine? Do you run a humidifier, or have you noticed your piano going out of tune when the heat comes on? Tell us in the comments.

Know someone who just moved a piano into a new home this fall? Send them this checklist.