Professional Boiler Services in Chapel Hill, NC

Yes, and those sounds are telling you something specific. Banging or kettling usually means mineral buildup is trapping water against the heat exchanger, creating steam pockets that burst noisily. Gurgling points to air trapped in the system. A low rumble often signals sediment collecting at the bottom of the tank. Each noise maps to a different repair, and ignoring any of them leads to bigger problems.

Boilers are less common in the Triangle than furnaces or heat pumps, but they're far from rare. Older homes in Raleigh — particularly in neighborhoods like Oakwood, Boylan Heights, and Five Points — often still run on their original boiler systems. And on the other end of the spectrum, newer custom builds in Apex and Holly Springs are installing hydronic radiant systems that rely on modern high-efficiency boilers. Whether your boiler is 40 years old or brand new, the fundamentals of diagnosis are the same.

What Those Noises Actually Mean

Kettling is the most common complaint we hear. It happens when limescale or mineral deposits build up inside the heat exchanger, restricting water flow. The trapped water overheats, turns to steam, and that steam collapsing is what creates the banging sound. Left alone, kettling stresses the heat exchanger and shortens its life by years.

Gurgling or bubbling sounds usually mean air is trapped in the radiators or baseboard units. This one's straightforward — bleeding the radiators often solves it. But if air keeps returning, there may be a leak somewhere in the closed loop that's letting air back in.

A whooshing or rushing sound near the circulator pump can indicate the pump is working too hard, possibly because of a blockage or a failing valve. And if you hear a continuous low hum that suddenly gets louder, the pump bearings may be wearing out.

Boiler Types We Work On

Our techs service every boiler type found in Triangle homes. Gas-fired boilers (both natural gas through Dominion Energy and propane), oil-fired units, electric boilers, and combination boilers that handle both heating and hot water. We also work on the hydronic systems that connect to radiant floor heating — these require careful attention to water pressure, glycol mixtures, and zone valve operation.

North Carolina requires licensed contractors for all gas boiler work, and for good reason. Gas boiler repairs involve combustion chambers, gas valves, and venting that must meet NC mechanical code. Our technicians carry the proper licensing and stay current on code changes.

Common Boiler Repairs

The most frequent boiler repairs we handle in the Triangle break down like this:

Thermostat and control issues account for about 30% of our calls. Sometimes the boiler is fine but the aquastat, zone valves, or thermostat wiring has failed. These are usually quick fixes.

Circulator pump failures make up another 20-25%. The pump is the heart of the system — when it fails, hot water stops moving through your radiators or baseboard units. You'll notice some rooms heating while others stay cold, or the whole system going lukewarm.

Pressure problems are common too. Boiler systems operate in a specific pressure range (usually 12-15 PSI for residential). Low pressure means a leak somewhere. High pressure means the expansion tank has failed or the pressure relief valve is stuck. Both need prompt attention.

Pilot light and ignition failures round out the list. Older boilers with standing pilots can have thermocouple issues. Newer units with electronic ignition can have igniter or flame sensor problems. Either way, no ignition means no heat.

When to Repair vs. Replace

Boilers generally last longer than furnaces — 15 to 30 years depending on type and maintenance. If your boiler is under 15 years old and the repair is under $1,500, repair almost always makes sense. Over 20 years old with a major component failure like a cracked heat exchanger? Replacement is usually the better investment.

Modern condensing boilers run at 90-95% efficiency compared to 80-85% for older models. That efficiency gap shows up on your Dominion Energy bill every month during heating season.

Our $49 Boiler Diagnostic

We offer a $49 boiler diagnostic that covers a full inspection of your system — combustion analysis, pressure testing, visual inspection of the heat exchanger, circulator pump check, and control system evaluation. We service all boiler types and brands. Our techs will tell you exactly what's causing the noise, what it'll cost to fix, and whether repair or replacement makes more financial sense for your situation.

If your boiler is making noises it didn't used to make, don't wait for it to stop working on a cold night. Most boiler problems are simpler and cheaper to fix when caught early.