If your boiler is leaking or you smell gas
A gas smell means leave the building at once and call the gas utility or 911 from outside. Do not hunt for the source. A boiler that is spraying hot water or dripping steadily from the relief valve discharge is also urgent, so shut off the power switch at the boiler and call.
A slow drip at a pipe joint can wait for a scheduled visit. Put a pan or bucket under it, keep an eye on the pressure gauge, and write down what you see so we can talk it through. Do not close the relief valve or cap it to stop a drip, because that valve is the last safety device on the system.
What to check before you call
These steps are safe for most homeowners and often make the phone call shorter.
Read the pressure gauge
Most residential hydronic boilers sit around 12 to 15 psi when cold. Near zero means water has been lost. Above 25 psi when hot is a warning sign.
Check the thermostat
Confirm it is set to heat, set a few degrees above the room temperature, and has fresh batteries if it uses them.
Look at the power and gas
The boiler switch should be on, the breaker should not be tripped, and other gas appliances should be working.
Note any error code
Many boilers flash a code or light pattern. Photograph the display and the data label with the model number.
Feel the pipes and radiators
If the boiler is hot but a room is cold, the problem is likely air, a zone valve or a circulator, not the burner.
Common hydronic boiler problems
Boilers fail in recognizable ways. This is what each one usually means.
Pressure keeps dropping
The system is losing water through a leak, a bad fill valve, or a worn expansion tank diaphragm.
Pressure climbs too high
A waterlogged expansion tank often lets pressure spike as the water heats and expands.
Relief valve dripping
Either pressure is too high, or the valve has worn and no longer seats. It should be replaced, not capped.
Banging or kettling
Sediment or scale on the heat exchanger can make the water boil locally and rumble.
Radiators cold at the top
Trapped air needs bleeding, which also means the system may be losing water somewhere.
Boiler cycles on and off
Short cycling can come from an oversized boiler, a bad thermostat, or a flow problem.
Planning boiler repair work?
Call for a clear price before work starts, and ask about same-day appointments when available.
No heat on a cold Zionsville morning
The National Weather Service lists the January average low for Indianapolis at 20.9 F for 1991 to 2020, and Indianapolis has recorded -27 F, on January 19, 1994. A boiler that stops on a night like that is an urgent problem, because pipes in an unheated house can freeze.
Indiana's Office of Utility Consumer Counselor advises keeping the thermostat no lower than 55 F when you are away, and finding your main water shut-off before you need it. If pipes do freeze, shut off the main right away and call a licensed plumber. Never use a torch or open flame to thaw them.
How we diagnose a no-heat call
We start with the thermostat call and the boiler's own sequence, then move down the line. Is the burner firing, is the circulator running, are the zone valves opening? A pressure gauge, a multimeter for the control circuit, and a combustion-side visual check tell us which of those fails.
If water is going missing, we pressure-test the loop and look at joints, the fill valve, the expansion tank and the relief valve discharge. Hidden leaks in slab heat or buried piping may need leak detection with listening gear. A boiler that makes smoke, soot or an unusual smell is shut down until it is checked.
Repair or replace the boiler
Age and condition decide this, not salesmanship.
| Situation | Usually | Why |
|---|---|---|
| Failed circulator, zone valve or fill valve | Repair | Parts are separate and the boiler itself is sound |
| Dripping relief valve, good boiler | Repair | Replace the valve and check the expansion tank |
| Cracked heat exchanger | Replace | This is the core of the boiler and is rarely worth fixing |
| Repeated leaks from the boiler body | Replace | Corrosion inside the vessel will keep coming back |
| Boiler is old and parts are hard to find | Discuss | Cost of the repair versus a new unit and the efficiency gain |
We will tell you honestly if a repair is not worth doing.
What we do and do not handle
We repair the water-side parts of hydronic systems, replace circulators and zone valves, swap expansion tanks and relief valves, and flush a system when sludge is the problem. If a gas supply line needs work at the meter, that is for the gas utility. Brand-specific burner or board work may need the manufacturer's trained technician, and we will tell you when that is the case.
We do not work on steam boilers unless we have confirmed it on the phone, and we do not promise to stock parts for every make. Ask us first, and we will give you a straight answer. Our water heater repair crews handle the hot water side of the house when a boiler also feeds a tank.
What affects the price of boiler repair
Prices depend on the part and the access, so a firm number needs a visit.
Which part failed
A zone valve or fill valve is a smaller job than a circulator or an expansion tank.
Boiler make and age
Parts for older units can take time to find, and some are no longer made.
Access
A boiler in a tight utility room or a finished basement takes longer to work around.
Leak location
A visible joint is quick. A leak under a slab means testing and opening a floor.
Time of day
An after-hours call is handled differently from a scheduled diagnostic visit.
Most homeowner policies respond to a sudden, accidental release of water and not to slow seepage, worn-out parts or the boiler component that failed. Read your policy and ask your agent how a boiler leak would be treated.
Call us for a clear price before work starts on your boiler.
Call (317) 740-1302Licensed work and nearby towns
The state requires a license to do plumbing for hire, and the Indiana PLA issues it. Before a stranger touches your heating system, look the name up on the state's online license verification. Permit questions about replacing a boiler go to the Zionsville Planning & Building Department.
Neighbours in Whitestown and other nearby towns can call too, and the Whitestown service area page explains how we cover it. For hot water from a tank instead, look at our water heater replacement page.
Frequently asked questions
Water is leaving the system. The usual causes are a leaking joint or valve, a relief valve that no longer seats, or a bad fill valve. A failed expansion tank can also cause pressure swings that look like a leak.
Most residential hydronic boilers sit around 12 to 15 psi when cold and rise a few psi when hot. Your boiler's label or manual gives the exact range. Zero means water has been lost, and a reading above 25 psi when hot is a warning.
Either the pressure is too high, often from a bad expansion tank, or the valve has worn out. Do not cap it. We check the pressure and the tank and replace the valve if it is worn.
Check the thermostat and the pressure gauge, then feel the pipes. If the boiler is hot but rooms are cold, air in the loop, a stuck zone valve or a failed circulator is likely. Call us with what you found.
No, and we will not claim to. We handle the plumbing side of many hydronic systems. For brand-specific burner or control boards, we will tell you if the manufacturer's technician is the better call.
Permit rules vary, so ask the Zionsville Planning & Building Department. Boiler swaps can involve gas and venting, so get the answer before you buy.
Yes. The Consumer Product Safety Commission advises battery-operated or battery-backup CO alarms on every level of the home and outside sleeping areas, preferably interconnected. That matters in any house with fuel-burning heat.
Sources
Figures and guidelines on this page are taken from these public sources. Local rules and utility details can change, so check the source before you rely on a number.
- January normal low 20.9 F (Federal agency)
- -27 F record (Federal agency)
- OUCC frozen pipe guidance (State of Indiana)
- CO alarm advice (Federal agency)