Gas/Oil Furnace & Boiler Flue Relining Experts Serving Delaware County

As homeowners, we tend to take our furnaces and boilers for granted, often forgetting that they sometimes need attention too. While your HVAC contractor may service your furnace or boiler annually to make sure the appliance itself is working properly, there are some misconceptions about what’s included in that annual service.

  • For one, you may think that your HVAC contractor cleans the flue that vents the appliance, but that’s not the case. You’ll need to hire a CSIA-certified chimney sweep to have your flue cleaned each year.
  • Secondly, you may think your HVAC contractor inspects the flue that vents the appliance, but that’s also not true. Your HVAC contractor does not inspect the flue for damage, and chances are, if damage is present, they will not offer flue relining services. In our experience, even when HVAC contractors do offer flue relining, the work is not done to our standards.

But just like the chimney venting your fireplace or stove, the chimney flue that vents your gas or oil furnace or boiler needs to be annually inspected, cleaned as needed, and relined if damage or deterioration is present.

Why & When Do Gas/Oil Furnaces & Boilers Need To Be Relined?

Both gas and oil appliances produce moisture and byproducts that can corrode and eat away at the metal or masonry flue liner. Once holes and cracks develop and corrosive byproducts build up, the flue will not function as efficiently or as safely as it should, and will need to be relined. You may also need to reline when updating your furnace or boiler, or when switching fuel types. Each liner must be sized and approved for the appliance and the fuel that it’s venting.

What Are the Signs That My Furnace or Boiler Flue Needs Relining?

There are quite a few signs you can look out for that may mean your furnace or boiler flue needs to be reline. Remember that a  damaged or deteriorating flue can pose safety risks and reduce the efficiency of your heating system, so keep an open eye for the following:

  • Visible Cracks or Damage: Are you able to get a good look up inside your flue? Keep an eye for visible cracks, gaps, or holes in the liner. This is a clear and obvious indication that relining is necessary.
  • Stains or Moisture: Water stains on the flue walls or any signs of visible moisture in the flue can suggest that the liner is damaged – or, at the very least, allowing moisture to penetrate the chimney structure.
  • Buildup: Are there byproducts or outside materials building up inside of the opening? If so, improper venting will be an issue, which can lead to damage or other inefficiencies.
  • Unusual Smells: Any unusual odors – and especially strong gas odors – in your home should be heeded. This may indicate a flue problem that’s allowing combustion byproducts to escape.
  • Visible Rust or Corrosion: For metal flue liners, rust or corrosion on the liner’s surface is a clear sign of damage or deterioration.
  • Reduced Efficiency: A damaged flue can reduce the efficiency of your heating system, so if you’re cranking the thermostat with no results to show for it, consider that your liner may be damaged.
  • Higher Energy Bills: Poor efficiency leads to upping your thermostat which leads to higher energy bills – all without the benefit of more warmth in your home.
  • Unexplained Health Issues: Health problems, such as respiratory issues or headaches, can sometimes be linked to a malfunctioning flue that is allowing the escape of harmful gases – like carbon monoxide.

If you notice any of these signs, it’s crucial to address the issue promptly. A damaged or deteriorating flue liner can pose safety hazards and reduce the efficiency of your heating system. Contact a professional chimney technician – like any of the crew members here at Lou Curley – to inspect your flue and recommend the appropriate repairs or chimney relining service.

What Are the Dangers of Using a Damaged or Dirty Furnace Flue?

Think about it. Your furnace flue has the important job of venting all the harmful byproducts produced by the appliance safely out of your home. This ensures a warm and toasty home for you – without compromising your household safety in the process. It’s clear, then, that using a furnace when the flue is damaged or clogged isn’t a good idea. But… what exactly can occur if you let this maintenance go?

  • Carbon Monoxide Poisoning: One of the biggest threats of a damaged flue is an increased risk of carbon monoxide poisoning. Carbon monoxide is a colorless, odorless gas that is produced during the combustion process, and when the flue is damaged or dirty, carbon monoxide can leak into your living space. Symptoms include headaches, dizziness, and nausea, so stay alert!
  • Fire Hazards: You rely on your furnace for warmth, but you don’t want that intense heat from the appliance to have access to adjacent walls or surrounding materials, as this can create a fire hazard.
  • Reduced Efficiency: A dirty or obstructed flue can greatly reduce the efficiency of your furnace. Essentially what this means is that it will work harder to get you your desired temps – and consume more energy in the process, leading to increased utility bills.
  • Draft Problems: Damaged or obstructed flues can cause draft problems, making it difficult for your furnace to draw in combustion air and vent exhaust gases. This can lead to improper combustion and potentially dangerous situations.
  • Corrosion: Moisture can enter a damaged flue and damage the furnace or boiler, leading to corrosion, which can be costly to repair or replace.
  • Health Issues: In addition to carbon monoxide, a damaged or dirty flue can allow other harmful pollutants to enter your home, leading to various respiratory problems and health issues.

That’s a lot to take in! And it’s why it’s so crucial to have your furnace flue inspected regularly by a professional technician to ensure it’s clean and in good shape. If any damage or obstructions are detected, they should be addressed immediately to prevent these serious safety and health risks. Never attempt to use your furnace if you suspect a problem with the flue – rather, reach out to us right away!

We’ll Do The Job Right

If you think you may need to have your boiler or furnace flue relined, give us a call. Oil and gas furnaces and boilers have different liner requirements, but our experienced furnace flue relining experts have the knowledge and training to outfit your flue with the perfect liner and do the job right. We do everything according to manufacturer’s instructions and requirements, so you know the job is done right, your warranty is intact, and your chimney system is ready to go.

Ready to have your furnace or boiler flue professionally relined? Call 610-626-2439 or fill out our online appointment request form to get started today!


Stainless steel liners are another flue relining option that you can discuss with our expert technicians.