Boiler Not Working? No Hot Water? 15 Things to Check to Restore Function

If your commercial boiler isn’t working properly, it can be a nightmare for you as a property owner or manager. Here’s a list of things you should assess if you find the boiler not working and no hot water. Even if you wind up having to call in the pros at Calray Boilers for assistance, you’ll have a better idea of what to tell us when you place a service request. That lets us allocate more or less time as needed for repairs, and we can bring the right tools and potential spare parts as well.

Things to Check Before Calling Your Boiler Experts

Is only the hot water not working, or is the cold water also not flowing?

The first thing to check is whether or not the problem is only with the hot water. If the cold water is also not running, you have a problem with your water supply, likely from one of the following:

• Water shut off (city citations or fines, unpaid bills)
• Broken water main (typically a neighborhood problem)
• Blocked water pipe (no water entering your building)
• Clogged filter (filtration system is so clogged that it functions like a blockage)
• Sudden drop in water pressure (e.g., fire hydrant use)

Is there no water at all coming from the tap, or is there cold water coming from the hot water tap?

No water points to a clogged or broken pipe. However, cold water coming from the hot water spigot means your boiler is likely the culprit (see below).

Are only certain units having problems?

Do certain parts of the building have no hot water, while others are fine? This means the problem isn’t with your boiler but with the distribution system. Either a major pipe supplying one segment of the building is blocked or leaking, or a valve is closed and needs to be reopened. It could also be that part of the building has poorly insulated pipes that need protecting.

Have any safety alerts or shutdowns been triggered?

Did your boiler shut down, did you hear any alarms, or have your controllers issued any alerts? This can happen if:

• The boiler tank water level gets too low and it’s in danger of overheating
• The boiler room gets too hot and components like pumps start to overheat
• The boiler or controller detects kettling, surging, cavitation, or other hazardous situations
• Smoke, carbon monoxide, or other dangerous elements are detected in the boiler area
• Operating pressure is exceeded or close to being exceeded

In most of these situations, it’s best not to try to start up your boiler again. Instead, call your boiler service experts and wait for them to see what happened.

Do you notice any leaks?

Leaks could be due to corrosion of the tank (which often indicates other interior problems), worn gaskets or seals, loose pipe fittings, and the like. If the leak is minor and is something you can fix in-house, you may be able to remedy the problem. Otherwise, it may require the assistance of a boiler pro and/or plumber.

Is the power to the boiler operational?

Your boiler probably runs on gas but uses electricity for all its pumps and ignition. Check to make sure you don’t see or experience any of the following from the boiler’s electrical components:

• Worn or frayed wires
• Loose plugs or electrical outlets
• Sparks or smoke
• Dimming lights when the boiler turns on
• Circuit breaker triggered

What about the water supply to the boiler?

Your water supply to the building may be fine, but what about the water filling the boiler tank? Is your boiler feeder operating properly? Sometimes the sensor that tells the feeder to activate can get stuck, causing the boiler water level to drop from lack of fresh water. If you use one boiler for heat and hot water, you could also have a problem with your condensate return lines.

What does the thermostat read?

Is the thermostat set properly for the desired temperature? When the boiler runs (assuming you can operate it), does the temperature range appear normal? It could be your thermostat is broken or has reached the end of its lifespan, meaning it “thinks” the boiler temperature is fine when it’s actually too low.

Is the boiler igniting properly?

When you turn the boiler on manually, or when it comes on automatically, does it ignite the way it should? Is the flame sufficient? Does it burn yellow or blue? You should see a blue flame; a yellow flame indicates incomplete combustion. This is often accompanied by a buildup of soot around the burner. The accumulation of soot can become so bad that it affects ignition and combustion.

Do your pumps sound normal?

Boiler systems have multiple pumps to supply fresh water to the tank, distribute heated water to taps, etc. You should know the sound of normal pump operation versus noises that sound wrong. Any grinding, shrieking, rattling, or similar sounds, as well as excessive loudness or vibration, should be reported to your pump specialist. The pump may be loose (you can try fixing any obvious loose mountings), it may need lubrication or new ball bearings, or it could be an internal problem that requires repair.

What does the boiler sound like when it runs?

Likewise, your boiler should sound normal when it runs. You don’t want to hear any sloshing, banging, or noises like gravel hitting the tank walls. These are signs of situations that will cause the boiler to shut down, like surging or kettling.

Is everything normal with your sights and gauges when the boiler is running?

You should have a baseline for what’s normal with the boiler, given to you by the manufacturer and boiler professionals. Hopefully, you are checking these parameters daily or weekly and noting readings in a log. A no hot water scenario should prompt you to double-check all your sights and gauges to see if any readings are abnormal.

Do you observe any broken, worn, hardened, or encrusted parts?

Looking at the boiler and nearby pipes, do you notice anything that indicates malfunctioning seals, broken parts, or encrustation with sediment or mineral scale? If you’re overdue for regular boiler maintenance and cleaning, you may have a clog or a leak that is affecting pressure or aspects of operation.

Is the boiler running fine, but no hot water is emanating from the taps?

Once you’ve given the boiler the once over and everything seems fine but there is still no hot water, only cold water, coming from the taps in your apartments, it’s time to look at your pipes and the outside temperature. It’s possible a main hot water pipe is poorly insulated and running along a cold wall, causing all the warm water to lose its heat before it reaches its destination. Insulating the pipe should fix the problem.

Can’t figure out what’s causing your lack of hot water? Or do you have a boiler problem that’s outside your maintenance wheelhouse?

Call Calray Boilers at 212-722-5506 or use our online form to schedule a service call. We can check all of the above for you, as well as other parts that only a professional should examine and adjust, so you get your hot water back as soon as possible.