TOH plumbing and heating expert Richard Trethewey discusses how to silence those noisy baseboard heaters
Our baseboard radiators get very noisy when the boiler kicks on. Can you tell me how to fix this?
—Kevin Reynolds, Logansport, IN
It may seem as though hot-water baseboard heating systems can’t help but make clicks, squeaks, and creaks, but in fact those systems should be completely silent. Most times, the noises can be traced to installation shortcuts that didn’t account for the way copper tubing gets longer as it heats up and shorter as it cools down. Fortunately, it’s fairly easy to diagnose and correct those lapses and get some peace and quiet during the heating season.
To start, turn down the thermostat and allow the tubing to cool. While you’re waiting, pop off the baseboard covers so that you can see the system’s innards: its fins and tubing. Now turn up the thermostat setting. As hot water is pumped into the tubing, listen for any noises and try to pinpoint their source. For instance, if the fins are making a clicking noise, check that they’re resting on a plastic slider that allows them to move smoothly back and forth at each metal support, a bracket called a carrier. Add sliders where they are missing, or reposition those that are off center.
If there’s a second tube in the baseboard running alongside the one with fins, make sure that it’s resting on some kind of spacer at each carrier to prevent metal-on-metal squeaking. Foam pipe insulation or weatherstripping felt will do the job, but I like the plastic suspension clamps made by SharkBite. They have nailing tabs that resemble Mickey Mouse ears, so I call them “Mickeys.”
Now focus on where the tubing exits floors and walls or runs through framing; that’s where you’re likely to hear creaking as the metal pipe rubs against wood. A Mickey or a long split plastic spacer can isolate the two materials and put a stop to that particular noise.
At this point, you’ve probably quieted most of the din. But if it continues, see whether there’s a good ¾-inch gap for the tubing to expand into at the end of each run. If not, the tubing is probably bowing and banging against the cover. To fix that problem, hire a plumber to cut out a small section and shorten its run, or install a corrugated flexible connector. Either way, that will require draining the zone, as I’m doing at left, and then refilling it when the work is done. Before opening the zone’s hose bib, the plumber should shut down the boiler, close the valves to the other zones, and have a bucket ready to drain the water into.
Shown: Before he can alter a zone of a hot-water heating system, Richard Trethewey has to drain that zone into a bucket.