The short answer
You can hear the boiler downstairs, but the living room is still cold. Before assuming the whole system has failed, separate two questions: is the boiler producing heat, and is that heat reaching the rooms? Those are different parts of the job. This guide is for hot-water heating systems with baseboards or radiators, not electric baseboards or forced-air furnaces.
Start with the pattern, not a replacement estimate
Write down whether every heated room is cold or only one part of the house. A whole-house problem points to a different diagnostic path than a single cold zone. Also note whether the thermostat is calling for heat and whether its displayed room temperature is falling. Hearing a motor does not prove that the burner is firing or that heated water is circulating properly.
A hydronic system relies on a boiler, circulation and room-side heat emitters working together. Weil-McLain explains those basic components. The sound from the basement is only one clue.
Four useful observations you can make safely
- Confirm the thermostat is in heat mode, with a setting above the room temperature. Look for a schedule or vacation setting that changed the request.
- Note which rooms are affected. Do not assume that upstairs and downstairs have separate zones unless you know how the controls are arranged.
- Record any visible error message and take a photo of the equipment label without removing covers.
- Look for obvious water on the floor from a safe distance. Do not touch hot piping, open valves or try to add water to the system.
What if the faucets still have hot water?
Tell the technician, but do not treat it as proof that the heating system is healthy. Your domestic hot water might come from a separate appliance. If the boiler also heats your water, a hot shower still does not establish that every space-heating control and circulation path is operating. Knowing whether you have a separate tank, an indirect tank or a tankless coil helps the conversation.
What the service visit needs to establish
Ask for a diagnosis of the heating request, boiler operation and heat delivery before approving a major replacement. Depending on the system, a technician may need to evaluate controls, circulation, zone operation or system condition. The same symptom can have different causes, so a parts list from an online article is not a diagnosis.
Bring any recent repair paperwork. A problem that started immediately after a thermostat change, service visit or building project deserves that context. Write down what changed and when, without trying to recreate the fault.
When not to wait
If a carbon monoxide alarm sounds, leave the building and call 911 from outside. If you smell gas or see smoke or fire, leave and call emergency services from a safe location. Do not stay inside to troubleshoot. Read the CPSC carbon monoxide guidance.
Arrange prompt heating service if the house continues to cool, the system repeatedly shuts down, you see leakage, or someone in the home is especially vulnerable to cold. Tell the dispatcher about indoor temperature and any concern about freezing pipes. Do not use an oven or outdoor combustion equipment as indoor heat.
Getting heat back in Greater Waterbury
For a home in Waterbury, Watertown, Middlebury or the surrounding service area, American Heating boiler service is the appropriate next step when simple thermostat observations do not explain the problem. A service request should describe the affected rooms and the behavior, not guess the failed part. Once the immediate issue is addressed, our Connecticut boiler maintenance guide can help you plan routine care.
Frequently asked questions
Why is my boiler running but my baseboards are cold?
The sound of a running motor does not confirm that the burner is producing heat or that hot water is reaching the baseboards. A technician needs to check the heating request, boiler operation and circulation. Note whether every room is affected or only one zone.
Can I have hot tap water but no central heating?
Yes. Domestic hot water may come from a separate appliance. Even when the boiler supplies both, hot tap water does not prove that the space-heating controls and circulation paths are working. Tell the technician which type of water heater you have.
Should I add water or increase the boiler pressure?
Do not make those adjustments based on cold rooms alone. The correct pressure and filling procedure depend on the equipment and installation. Report visible leakage or a gauge reading from a safe position, and leave filling and pressure diagnosis to a qualified technician.
Does a no-heat problem mean I need a new boiler?
Not necessarily. A problem with controls or heat delivery can leave rooms cold even when the boiler itself does not need replacement. Ask for the cause, proposed repair and condition of the system before deciding on an upgrade.
Talk with American Heating
Request boiler service or call 203-756-5040. Describe your equipment and what you have noticed so the team can help identify the appropriate next step. You can also send a service request online.
References and further reading
- Weil-McLain: heating-system glossary
- Weil-McLain: boiler winter-readiness guidance
- CPSC: carbon monoxide fact sheet
References checked September 21, 2026. General homeowner information, not a substitute for the instructions supplied with your equipment or an on-site diagnosis.
Cover illustration generated with AI for American Heating. It is a conceptual editorial image, not a customer installation or technical diagram.