A noisy baseboard heater can be disruptive in a quiet, peaceful home, and many homeowners are at a loss to explain why they produce sounds. Fortunately, there are usually fairly simple causes at work, and most of the time, homeowners are able to implement a solution that will end the noise. Below is why baseboard heaters produce noise and what you can do to correct the trouble:
Causes of baseboard heater noise
The root cause for baseboard heater sounds is thermal expansion. As the pipes inside baseboard heaters heat up, the metal expands and leads to rubbing and binding between parts. Noise can even be produced when heater components interact with structural components such as joists or studs. The key to solving the problem of excessively loud baseboard heaters is identifying where the rubbing occurs and implementing a solution.
How to quiet a noisy hydronic baseboard heater
Since hydronic baseboard heaters depend on the flow of hot water through the individual units, it is important to identify where pipes make contact with other components inside the heater. The hot water pipe that flows through a given unit is usually suspended on brackets inside the heater. These metal brackets are typically not large, and they are crafted from lightweight materials. As the pipe expands across the bracket, it rubs across the bracket much the same way that a bow passes over a violin string. This creates a loud, unpleasant sound that is amplified by heater components.
To fix this problem, you will need to:
1. Identify where the brackets make contact with the pipe - Begin by turning off the hot water feed to the baseboard heater; this will protect you from being scalded in the unlikely event the pipe ruptures or a leak occurs. Next, once the system has cooled down, remove the covers to the individual units and look underneath the suspended water pipe. Make a note of where all brackets are located and also where the pipe passes through a nearby wall, if it touches the wood or drywall.
2. Cut pipe sleeves from PVC pipe - Once you have counted up the number of brackets, measure the diameter of the water pipe. Next, add one-half inch to the diameter, and this will provide a sleeve measurement. Sleeves are made from Schedule 40 PVC pipe, and the sleeve measurement will tell you what size pipe to purchase at the hardware store. For example, for a one-inch water line inside a baseboard heater, you will need to purchase one-and-one-half inch PVC pipe to create the sleeves.
After you buy the pipe, measure two-inch sections along the PVC pipe and cut them out using a hacksaw or PVC cutter. Fit the two-inch sections into a vise, being careful not to crack them, and make longitudinal cuts down the middle of the pipes with a hacksaw. Only cut through one wall of the pipe; your goal is to cut the sleeves in such a way they can be slipped over the water pipes in the hydronic system. If there are excessive shavings on the sleeve edges, use a piece of fine grit sandpaper to remove them and clean the edges.
3. Attach the pipe sleeves to the hydronic pipe system - After the sleeves have been made, you can install them in the baseboard heater. Return to the brackets you noted in step 1, and carefully spread the PVC sleeves outward and slip them over the water pipes. Once the sleeves are wrapped around the pipes, carefully slip them into position, so they separate the hot water pipes from the brackets.
If you notice there is a tight fit between the pipes and the wall studs or other support structures, you may also wish to install a PVC sleeve to prevent rubbing against these components. Be sure to avoid damaging the water pipes during installation of the sleeves, and never treat them as weight bearing objects. Otherwise, you could break soldered joints or even crush the softer copper lines.