Why Do Baseboard Heaters Make Noise?

Baseboard heaters are a common feature in many homes, apartments and office buildings. The heaters are installed along the base of the floor and come in various lengths and voltages for varying needs. Generally speaking, baseboard heaters should operate fairly quietly, but if the baseboard heaters seem to be making noise, there are several possible reasons for that.

Baseboard heater
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Baseboard heaters may make noise when initially heating up.

Pinging

When your baseboard heater makes a pinging noise, the metal fins inside the covers are rubbing against each other. The fins may be bent or crushed, which makes noise when the heat inside the unit causes the fins to expand. Remove the covers from the heaters and straighten the fins carefully. Cut small pieces of wax paper and slide the wax paper between the fins where the fins touch the baseboard.

Knocking

A knocking sound from inside the baseboard heater is caused by the expansion of the pipes when hot water enters the pipe. When cold water enters the boiler to be heated and hot water flows into the baseboard and then back into the boiler, the pipe expands and creates noise. The expanded pipe then rubs against the floor. Place insulators or wax paper pieces between the pipe and the wood to help muffle the sound.

Banging

A banging sound from the baseboard heaters frequently originate in the boiler. This is created by air in the system and a zone valve that closes too quickly. The zone valve closes when the circulator is running, which causes pressure to bounce against air in the system and force the valve to open slightly again. This creates the banging sound. Look at the pressure gauge on the boiler, which should be between 12 and 20 PSI. Contact a plumber for assistance if the air pressure is not between 12 and 20 PSI. Note that too much air in the system can also make it sound like there is water rushing through the pipes.

Hammering

If it sounds like the pipes are being hit with a hammer, the temperature in the hot water boiler may be too hot. Look at the temperature gauge and shut the boiler off if the temperature is above 220 degrees Fahrenheit. Contact a heating service technician for assistance as soon as you can.