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My Boiler Won't Turn On! A New York Tech Explains

April 14, 2020


If your boiler won’t turn on at all (i.e. you don’t hear the thermostat click and the boiler doesn’t even attempt to start), don’t reach for the phone just yet... 

There are actually quite a few things you can try at home before you call in the professionals. 

Before you call for help, check to see if the...

  1. Thermostat is working correctly

  2. Boiler switch is “ON” and the circuit breaker hasn’t tripped

  3. Gas valve is turned “ON”

In this article, we’ll go through each of these steps in detail so you can potentially fix the issue on your own. However, if you’ve tried all of the above and your boiler still doesn’t start up, you’ll need to call a professional.


Want your boiler repair work done right the first time? Schedule an appointment with our experts online or by calling us at (718) 767-0707. We have 50+ years of experience you can always count on.


Boiler troubleshooting tips: 3 issues to check for

1. Make sure your thermostat is working correctly

It may sound obvious, but double-checking that your thermostat is on and set to “heat” or “auto” is the first thing to look for. Also, check to make sure the batteries inside the thermostat are still working.

Or, there could be an actual issue with the thermostat itself. 

To test that your thermostat is working correctly, raise the temperature at least 5° higher than the current room temperature. If your boiler doesn’t kick on, your thermostat might not be working properly and you may need to call a professional to diagnose the issue. If the boiler does kick on when the temperature is raised, there likely isn’t a serious issue with your boiler or thermostat. 

Here’s the underlying issue: Different thermostats are designed to have varying “differentials.” Simply put, some thermostats are programmed to call for heat only once the room temperature falls a certain number of degrees below the set temperature. For example, some thermostats have a differential of +/-1°, while others have a higher differential of +/-4°. 

If you’d prefer for your boiler/thermostat to have a lower differential, you can contact a tech to visit your home and reset your thermostat settings.

2. Make sure the boiler switch is turned “on” and the circuit breaker hasn’t tripped

Even with a gas boiler, parts of your system need electricity to operate, such as the electronic ignition system. If there’s no electricity, these components can’t start and the start-up process of your boiler will be completely halted.

The first thing to check is if the power switch to the boiler is turned on. The switch, which looks just like a light switch, is usually located at or near the boiler, or at the entrance of the boiler room/basement. If the switch is in the on position, the next thing you’ll want to check is the circuit breaker.

To check your breaker, go to your electrical panel and look for the breaker labeled “boiler.” Double-check that your breaker is in the ON position. If the breaker has tripped, push it into the ON position. If your boiler automatically kicks on shortly afterward, you’ve found your issue. If not, something else may be the issue. 

Note: If the breaker immediately trips again as the boiler tries to start, contact a professional as you likely have a larger electrical problem. 

If your boiler’s circuit breaker isn’t tripped, continue on to step 3.

3. Make sure the boiler gas valve is open

Every gas boiler has a valve which controls the supply of gas to the boiler. In order for your boiler to start, it must be open. You can check to see if your boiler’s gas valve is in the open position by locating the gas pipe. The gas pipe typically runs alongside the boiler and has a valve. Make sure the valve’s lever is running parallel to the pipe and not perpendicular.

If the lever is perpendicular to the gas pipe, the gas is shut off and isn’t flowing to the boiler. 

Note: If you’re not sure where your gas valve is located, do not attempt this step. Adjusting the gas valve/pipe improperly could result in a dangerous gas leak. Always have a professional handle this step if you’re not familiar with how your boiler works.

Gas boiler still not starting?

If you’ve gone through all four troubleshooting steps and your gas boiler still won’t turn on, you most likely have a larger problem and you’ll need professional assistance. If that’s the case, we’ve got you covered. Schedule an appointment with us and we’d be happy to diagnose and repair your boiler.

With over 50 years of experience providing boiler repairs in the Queens area, our techs are industry experts when it comes to repairing most makes or models. They’ll be able to inspect and diagnose your boiler quickly, as well as present you with fair and honest repair options and pricing.

Choose Ranshaw for a boiler repair done right, the first time around.


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