How to prep your boiler for winter

As cold weather approaches, now is the perfect time to be thinking about your heating system. Boilers are known for their dependability, but they need regular maintenance to perform their best. 

Below you’ll find some helpful tips for getting your boiler ready for winter now, while you have time to go slow and learn if you’re new to boiler maintenance, or to call a professional if there’s a repair that’s too much for you to handle.

Why you need to get your boiler ready​

Like other kinds of mechanical equipment, boilers can develop problems over months of inactivity. Following the steps below can help work properly when you need it. It will likely also improve your heating efficiency, safety, boiler lifespan and home comfort. It may also help keep your warranty valid if proper maintenance is a condition of your coverage. 

1. Get a professional tune-up​

Appliances and home systems have gotten much more efficient over the last few decades, but they’ve also gotten more complex. This complexity, combined with the presence of carbon monoxide that’s produced during combustion in a gas boiler, make doing serious repair work on a boiler best left to the experts. 

A boiler tune-up by a trained technician may consist of maintenance and repair work, from minor tweaks and cleaning to major fixes, if needed. For example, a Home Service Plus® (HSP) ​ boiler checkup includes testing for unsafe levels of carbon monoxide, restarting the boiler, fixing faulty parts or controls and more. 

2. Inspect for water leaks​

You should inspect your boiler for leaks on a regular basis, not just during the run-up to winter, and autumn is the most important time to do it. 

If you have to keep refilling the boiler with water, you may have a leak somewhere that needs to be located and repaired. Theoretically, you should never have to refill a boiler–the closed loop system recycles the water for heating again and again. 

Search for any water spots or pools around the boiler, and the radiators as well. Leaks are commonly related to loose joints, damaged rubber seals or pressure issues. 

Although a small amount of “weeping” from the pressure release valve is acceptable, if there’s too much pressure in the boiler–as reflected by the pressure gauge being ‘in the red’--it can cause a leak, so the boiler must be bled. Boilers should be bled at least once or twice per year for older boilers with manual bleed valves. Remember that automatic valves can fail, so they’re not a guarantee of correctly regulated pressure. Follow the steps in your boiler manual for bleeding a pressure valve, or let a professional  technician handle it. 

If there is water appearing around boiler fittings or joints, try tightening them to see if that resolves the issue. 

Hardened and worn-out seals, as well as leaking cracks in the body of the boiler, can be temporarily patched by adding a powder or liquid sealant to the system.   

3. Check for a clear blue flame​

Take a look through the boiler’s sight window to inspect the flame. If it’s a clear blue, it’s healthy. An orange or yellowish flame indicates incomplete gas combustion and higher levels of CO2 being created. You’ll need a technician to diagnose the cause and fix it. 

4. Check for smells and noises​​

Boilers can make some frightening noises, but generally these simply indicate poor efficiency. If you hear clunking, popping or cracking, it’s likely caused by a buildup of mineral deposits inside the tank and you’ll need a technician to flush the boiler. ​

A bad smell from the boiler could be more serious. A rotten eggs smell can indicate bacterial growth. If you smell smoke, you could have a clogged flue or vent. Most importantly, the smell of gas could be due to a gas leak, which is an emergency cause for immediately shutting off the boiler and getting professional help. 

5. Clean the boiler

For optimal efficiency, you should clean the boiler of dirt and debris, inside and out. After turning the boiler off, disconnecting it from both power and fuel supplies and waiting for it to cool down, remove any corrosion, dust, or residue that has built up on the blower with a wire brush and vacuum. ​

Then remove the cover so you can access and clean the tubes in the heat exchanger, the combustion chamber walls and the bottom of the boiler. 

The boiler’s flue pipe needs to be kept clean as well. Although it may not need cleaning every year, rodent or bird droppings, soot and debris can become lodged in the flue and hinder the boiler’s exhaust and efficiency. Depending on the length of the flue, you may be able to clean it adequately with a correctly sized flue brush, but scheduling a professional cleaning may be the best option. 

6. Clear space around the boiler​

Adequate airflow is vital for the proper functioning of your boiler, so you also need to clean the area around it.

Leave the area around the boiler cleared of storage items such as clothing, shoes, boxes, luggage, etc. For the same reason, clean air intake vents and make sure they’re unobstructed by furniture or decor. 

7. Test detectors and thermostat​

Your boiler room should have a smoke and carbon monoxide detector installed according to the manual placement guidelines, typically 10-12 feet away. 

During the fall, replace the batteries on the alarm (if it has battery backup) and press the test button to make sure it’s active. Also stock up on batteries, especially if the detector uses less common batteries such as 9V. 

8. Test the boiler before winter​

A few times over the summer and early fall, before you need to fully put it into service, turn your boiler on for a test run. Ten to 15 minutes is enough to gauge whether the pressure is right and everything is working correctly. 

9. Prepare for the worst

Even with the best maintenance routine, boilers can still break down. To be ready for the possibility of being without heat for several days, make sure you have access to firewood (if you have a wood-burning stove or fireplace), plenty of blankets and warm clothing, hand warmer and toe warmer packs and heavy sleeping bags.  

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