Fixing Noisy Electric Baseboard Heaters

We’ve dealt with the problem of noisy electric baseboard heaters for a decade now in our second floor bedrooms.

Picture of a bedroom installation of electric baseboard heating.

Electric Baseboard Heater, Bedroom Installation

Electric baseboard heating systems are terrific for supplementing the primary heating system (the furnace) in the home. However, unless you’ve spent the extra money for a quiet hydronic heater, electric baseboard heaters generally tend to be noisy. They ping, pang, pop, squeak, squeal, and ring even, when energized, as the warming parts change size. buzz, and vibrate. Then, when the thermostat turns them off, these heaters make the same noises as their metal parts and the heating element itself shrink during cool-down.

Here are a couple of the tricks we’ve attempted with moderate success, to   fix or   reduce the electric heater noise. Note that these procedures apply only to convection type electric baseboard heaters, as these tend to exhibit lower surface temperatures than the hotter, radiant units.  Do not use lubricants on or near any glowing-type heating elements found in radiant heat sources.

  • Lubricate all brackets, joints, and any places where different pieces of metal meet and could rub and bind. Since many of these joints get quite hot during normal heater operation, be sure to use a thick oil or grease that can withstand these high temperatures without drying out, catching fire, or otherwise breaking down. We’ve used the WD-40 Specialist Water Resistant Silicone Lubricant, and various brands of white lithium grease with some positive results. Unfortunately however, no oil or grease that keeps electric baseboard heaters quiet without periodic re-application. Typically, we’ve “re lubed” the heaters biannually.
  • Reinforce all brackets and joints. Hoping to reduce the need for lubricants mentioned above, we’ve reinforced the metal stand-off brackets in typical electric baseboard heaters. These brackets suspend the resistive heating element (which resembles a long, thin bar that sports many heat fins). During warm-up and cool-down, we determined that the places where these brackets are fastened to the heater cabinet created much tapping, squealing, ringing, and clicking. So a single hole was drilled in each bracket where, it meets the cabinet, and then we drove a sheet metal screw through. For eight foot long 2500 watt electric baseboard heaters, this required eight holes be drilled and eight screws to secure (two screws per bracket). This step showed the greatest noise-reducing effect. While they still click and pop some, they do so far less than before the sheet metal screws were applied.  The squeaks and squeals completely disappeared.
  • Tighten all screws   that secure the heater to the baseboard or wall.  Preferably, the screws should be driven into studs or substantially-sized wall anchors, to provide a more solid, less vibration transmitting backing for the electric baseboard heater.
  • Secure the heating element.  Electric baseboard heaters also tend to hum while operating; especially the higher power residential units like ours. This hum problem wasn’t as easy to address as the squeaks, pings, and pops. But hum has been minimized by assuring that the heating element is secure in the standoff brackets mentioned above. This can reduce the buzzing sounds that result when a loosely secured heating element vibrates within the standoff bracket.  The bracket should clamp the heating resister tightly.  Bending the bracket can be done to provide this more snug fit.  But do not flex the bracket too many times; lest it break apart on you.
  • Choose a thermostat wisely, to control your electric baseboard heaters.  This becomes critical now that electronically switched (triac based) thermostats have made their ways into mainstream markets.  These devices employ the same device (a triac) for switching as do light dimmers, and anyone who’s ever experimented with a light dimmer knows that the light itself, as well as the dimmer unit, can buzz loudly when the dimmer is not set at the brightest (fully on) position.  Well, it’s also the case that a poorly designed electronic thermostat may not always turn the triac fully on during each AC power sine wave cycle, and can thus, lead to louder-than-usual buzzing in your electric heater, not to mention generating lots of radio and TV interference (RFI). Thus, replacing your thermostat may solve some buzzing problems.  Temporarily bypassing the thermostat you have by applying jumpers across its switched terminals will verify whether your thermostat is introducing the buzzing.  If the buzz disappears when you jumper the thermostat terminals, but the heater remains on, then the thermostat is your culprit.  If you do replace the thermostat though, use caution when selecting an electro-mechanically switched model.  These contain physically operated micro switches, that click when turning on and off.  Thermostats like these can therefore add their own brand of distracting noises to the base board heating cacophony.
  • Replace the Heater.  Sadly, the cheaper, non-hydronic electric baseboard heaters are inherently noisier, and so, may not be suitable for bedrooms or other areas requiring the quietest possible environment. The hydronic liquids in these superior appliances completely encompass the heating element, which tends to mitigate vibration transmissions.  Plus, they keep the element cooler during operation.  In hydronic electric heaters therefore, you don’t have the large temperature swings within the heating element when going from cold to hot that you do in more modestly priced heating units.  So there’s less expansion and contraction of the element itself and supporting brackets, screws, the case, and other securing parts.  As a result, you experience less noise overall from baseboard-bound hydronic units.  With hydronic heat plants, you indeed get what you pay for.

We may eventually replace our bargain-basement 220-volt heaters with hydronic baseboard heaters. And in fact, there are lots of very quiet heating units on the market today.  We’ve observed them in operation in the homes of friends and on school campuses.  But until you’re ready to purchase these top-notch heaters, the steps outlined above have proven to make our existing heaters quiet enough to tolerate; especially with a white noise sound conditioner or fan operating nearby to mask their noises.

References

Revision History

  • 2014-10-12: Added pictures, the References section, and more content about the advantages of hydronic heating.
  • 2012-03-01: Originally published.

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