Boiler Not Heating Water? How to troubleshoot (Quick Tip)

Boiler Not Heating Water? How to troubleshoot (Quick Tip)
Author

Sam Leslie

Owner | Mesa Plumbing, Heating and Cooling

Table Of Content

If your boiler isn’t heating water and you searched for “boiler not heating water,” don’t worry — you’re in the right place. Here’s a quick, safe, and simple way to get your heat and hot showers back in just a few minutes. If anything seems off or you smell gas, stop and call a pro.

1. Confirm the Call for Heat

Set the thermostat to Heat and raise the set point a few degrees. Replace the batteries if it is a battery model. Many no-heat calls are solved right here.

2. Check the Boiler Power

Make sure the boiler switch near the unit is on and the electrical breaker is not tripped. Reset the breaker once only. If it trips again, call for service.

3. Read the Pressure Gauge

Most homes want about 12 to 15 psi when the system is cold. If the gauge is near zero, the boiler may lock out, and you’ll still see “boiler not heating water” even though controls look fine. Do not add water unless you know the procedure. Note the reading and call for help.

4. Listen for Clues

A steady boiler clicking with no heat sound can point to ignition issues, air in the loop, or a stuck relay. Clicking with no burner light often needs a technician to clean the flame sensor or check the ignition module.

5. Look Outside at Intake and Exhaust

High-efficiency boilers breathe through PVC pipes on an exterior wall. Clear away leaves, ice, or snow. A blocked pipe will cause lockouts, and you’ll still find the boiler not heating water after resets.

6. Check the Condensate Drain

If you have a condensing boiler, make sure the clear drain tube is not kinked or frozen and that water is dripping during operation. A blocked drain will shut things down for safety.

7. One Safe Reset

Use the appliance reset button once only after the checks above. If it trips again, stop. Repeated resets can make the problem worse.

8. When to Call Now

If you smell gas, hear a carbon monoxide alarm, notice water leaking from the relief valve, or see pressure above 30 psi, stop and get professional help immediately.

Quick pre winter maintenance to prevent no heat

A little residential boiler maintenance before the first cold snap boosts reliability and supports the energy efficiency pillar of your home.

  • Annual tune up with combustion analysis and safety checks
  • Expansion tank charge and circulator inspection
  • Air removal and a quick bleed at problem radiators
  • Water quality test for pH and inhibitors
  • Vent and condensate system cleaning and freeze protection review

These steps reduce short cycling, quiet gurgling, and keep your system efficient so you are not stuck with a boiler not heating water when the first freeze hits.

Why is my boiler running but radiators are cold

Air in the loop, a stuck zone valve, or a failed circulator can move noise but not heat. Start with a thermostat check and a pressure reading. If pressure is normal, schedule service to purge air and test components.

Around 12 to 15 psi when the system is cold works for many homes. Taller homes may need a bit more. If you see near zero or above 30 psi, call a professional.

Try one reset after basic checks. Ongoing clicking with no heat often points to ignition or flame sensing that needs cleaning or replacement. Do not keep resetting.

Do you have more questions about Boiler?

Need a pro? Call Mesa Plumbing at (720) 680 2303 or schedule at www.mesa-plumbing.com. We service Boulder and nearby communities with same day options before winter weather moves in.