99 cities and towns covered
Oil-to-Gas Flue Conversion in Connecticut
Connecticut runs more oil heat than any state in the country, so it does more conversions than most. The part that gets left out of the quote is what happens to the chimney.
Leave the building and call from outside — that is an emergency services call, not a service call. A blocked or failed flue is one of the ways carbon monoxide reaches a living space, and headaches that clear when you leave the house point the same way. If you have had a chimney fire — a roaring sound, dense smoke, or debris on the roof — do not light another fire until the flue has been inspected.
Call about a flue conversion
(844) 785-4066Free to use, and there is nothing to pay us. You are never committed to going ahead.
What happens when you call
- You describe the problem and where you are.
- We put you in touch with a licensed contractor covering that area.
- They arrange the visit and agree the price with you directly.
Worth having to hand
- Roughly how old the system is
- What it is doing — or not doing
- Your ZIP code
What to ask for on Oil-to-Gas Flue Conversion
- Liner sized from the appliance venting tables
- Insulation where the chimney runs cold
- New thimble and sealed abandoned openings
- Camera survey before and after
- Licensed & insured We match you with contractors who hold current licensing and cover.
- Know what to ask Every page says what decides the price, so you can judge a quote.
- Free to use We never charge you. Compare quotes and walk away at any point.
- Same-day reply Inquiries answered the day they arrive, usually within a couple of hours.
How it works
Three steps, no obligation at any of them.
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1
Call and tell us what is wrong
Describe the problem and give us your ZIP code. We match you with a chimney company covering your area — there is nothing to fill in and nothing to pay us.
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2
A local contractor gets in touch
A local chimney company contacts you to discuss the problem and arrange a visit. What they charge to attend or diagnose is theirs to set, so agree it with them up front.
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3
You decide
Book the work, wait a season, or get a second quote. There is no obligation to go ahead with the contractor we introduce you to, and nothing to pay us either way.
What these repairs look like
Illustrative examples of the work described here. More in our disclaimer.
Why the chimney is part of the job
An oil boiler produces a lot of hot flue gas. A modern gas boiler produces far less of it and produces it cooler. The chimney does not change, so after a conversion the appliance is venting into a flue several times larger than it needs.
The consequences are immediate and they compound. The gases cool on the way up, they condense, the condensate is acidic and it soaks into mortar joints and flue tile. The flue also does not draw the way the appliance expects, which is a combustion issue rather than just a masonry one.
None of this is exotic and all of it is avoidable. A correctly sized stainless liner is part of doing the conversion properly, and it should appear on the quote next to the boiler rather than as a surprise afterwards.
Getting the size right
Diameter comes from the appliance manufacturer's venting tables, based on the input rating and the height and configuration of the chimney. It does not come from what fits. Ask to see the table.
Insulation on cold chimneys
Exterior chimneys, chimneys on unheated walls and tall runs all shed heat from the liner. Where they do, insulation is what stops condensation happening even at the correct diameter. On an exterior stack in Connecticut this is usually required rather than optional.
The details that get skipped
Beyond the liner, a conversion leaves loose ends in the chimney, and they are the things that get missed when the focus is on the boiler.
The abandoned opening
Where the old oil appliance connected, there is a hole in the chimney. It needs properly sealing with masonry, not covering with a plate. An unsealed opening lets flue gases into the basement and lets air into the flue, which affects the draft.
Anything else venting into that chimney
A water heater frequently shares the flue. If the boiler leaves and the water heater stays, that water heater is now alone in a flue sized for two appliances, which is its own oversizing problem. It needs including in the sizing calculation, not discovering afterwards.
A camera survey either side
Before, to establish what condition the flue is in after decades of oil. After, to confirm the liner is properly seated and connected. Both are quick and both are worth insisting on.
Oil-to-Gas Flue Conversion — frequently asked questions
Is the liner included in a standard conversion quote?
Frequently not, and that is the single most common cost surprise in a Connecticut conversion. Ask explicitly whether flue relining is in the price before you sign anything.
Can we reuse the existing flue if it is in good condition?
Condition is not the issue — size is. Even a perfect flue built for an oil boiler is too large for a modern gas appliance. Good condition means the masonry does not also need repair.
What about the old oil tank?
That is a separate trade, and in Connecticut an underground tank has its own removal and reporting requirements. Worth sequencing alongside, but it is not chimney work.
How long does the chimney side take?
A straightforward liner is usually a day. Bends, offsets, crown rebuilding or masonry repair extend it. Getting the survey done early is what keeps the boiler and chimney work on the same schedule.
Do we need a permit?
Typically yes, and requirements vary by municipality. Ask who is pulling it. A conversion involving gas piping and appliance venting is not work to do unpermitted.
Oil-to-Gas Flue Conversion near you
We cover cities and towns across Connecticut.