Baseboard Heat Not Working? A Practical Checklist
Last updated Reviewed by Waseem Shahzad, Lead Technician
Smell gas or hear a carbon monoxide alarm? Leave the house first, then call 911 or the gas utility from outside.
Is it one room, one zone or the whole house?
Start by working out how much of the house is cold. One cold room points to that baseboard: air, a closed damper or something blocking it. One cold zone points to its thermostat, zone valve or circulator. The whole house cold points to the boiler itself. That one answer saves a lot of guessing.
For the reasons behind each of these, our article on baseboard heat not working in one room explains air, pressure and zones in more detail. This page is the checklist.
What should you check first?
Check the thermostat for that area, then the baseboard itself, then the boiler gauge. Most cold-baseboard calls in Long Island homes come down to a thermostat, a closed damper, a blocked fin, air in the loop or a zone valve that stopped opening.
- Thermostat: Set the cold zone's thermostat to Heat, several degrees above room temperature. Replace the batteries if it has them.
- Damper and fins: Make sure the damper flap along the top of the baseboard cover is open, and nothing (furniture, curtains, bedding) sits against it.
- Feel the pipe: After the zone has been calling for 15 minutes, carefully feel where the pipe enters the baseboard. Warm at one end and cold at the other suggests air or a flow problem.
- Check the boiler gauge: Note the pressure. Low pressure can leave upper floors cold. See our boiler pressure guide.
- Listen at the boiler: Gurgling in the pipes suggests air. A boiler that fires while the zone stays cold suggests a zone valve or circulator.
What should you not do?
Do not open bleed screws on a system you do not know, especially when pressure is low, and do not open the boiler, force a zone valve lever or drain anything. Letting air or water out without topping the system back up can leave the whole house colder than before.
- Do not cover or block baseboard with furniture or curtains.
- Do not use a space heater near curtains or bedding while you wait.
- Do not keep running a boiler that is leaking or whose relief valve is discharging.
When should you stop and call?
Call if the whole house is cold, if a zone stays cold after the thermostat checks, if you see water around the boiler or baseboard, or if the pressure gauge is very low or near 30 psi. If you smell gas or a CO alarm sounds, leave the house and call 911 from outside.
On a freezing night with no heat, open cabinet doors under sinks on outside walls and let a faucet drip while you wait. Our no-heat page covers more.
What does K2 do about cold baseboard heat?
We check the thermostat and zone wiring, the zone valve or zone circulator, and the boiler, then purge air from the loop, clean dust-packed fins if needed, and replace failed air bleeders. You get the cause and the price before the repair.
In a Huntington home stuck at 63 degrees, the fins were packed with dust and three air bleeders were leaking. In Dix Hills, air in the system kept one of three zones cold. In Deer Park, a zone valve assembly had to be replaced.
Common questions
Why is my baseboard hot at one end and cold at the other?
Usually air trapped in the loop or a restriction in flow. Purging the zone and checking the air bleeders normally fixes it.
Do dusty baseboard fins really matter?
Yes. Baseboard heats by air rising through thin fins. When the fins are packed with dust, much less heat reaches the room even though the water is hot.
Should I bleed my baseboard myself?
Only if your system has manual vents, the pressure is normal and you know how it refills. Many Long Island systems are purged at the boiler, which is a job for a technician.
Need a technician?
Call or text us 24/7 from anywhere within 15 miles of Deer Park. You get a time window and the price before any repair.
Call 24/7: (631) 414-7141