Answering 24/7
Chimney liners for water heaters and boilers in Minneapolis
When a furnace moves to PVC venting, the water heater or boiler left in the old masonry chimney often cannot draft properly on its own. A correctly sized liner fixes that, and a draft test tells you whether you need one.
- 24/7 calls answered
- Minneapolis service office
- Sized liner matched to the appliance
- CO check every visit
Quick answer
A chimney liner in a Minneapolis home is usually needed after a furnace or boiler is replaced with a PVC-vented unit, leaving a water heater alone in a masonry chimney too large for it. City guidance puts the responsibility on the installer to confirm the remaining appliance vents safely, which starts with a draft test.
Boilers & Water Heaters
Why an old chimney stops working for one appliance
A masonry chimney sized for a furnace and a water heater together works because the furnace sends a lot of hot exhaust up it. Take the furnace out, and a small water heater's exhaust cools in the big cold flue, drafts weakly, and condenses on the inside of the masonry. The result is spillage at the water heater hood, crumbling mortar and, in the worst case, carbon monoxide in the basement.
The fix is a liner sized to the appliance that remains, or moving that appliance off the chimney altogether with a power-vent water heater. We test before recommending either, because some chimneys still draft well enough without work.
Compare
Liner, power vent or new vent
| Option | Works when | Watch for |
|---|---|---|
| Chimney liner | The chimney is sound and the run is reasonable | Cost rises with height and tile removal |
| Power-vent water heater | A side wall is close by | Needs an outlet and PVC route |
| Leave as is | Draft tests pass with margin | Retest after any other vent change |
Cost factors
What moves the price
Fixr's national figures put chimney liner installation at $1,800 to $4,000, around $2,500 for a flexible double-wall stainless liner. Here is what moves a job.
- Liner type. Flexible stainless, rigid stainless and aluminum differ in cost and lifespan.
- Chimney height. Longer runs need more liner.
- Flue condition. Old clay tile may need removing before a liner fits.
- Appliance size. The liner diameter is matched to the appliance input.
- Cap and connector. A new cap and vent connector are part of the job.
- Masonry repair. Crumbling crowns or loose bricks may need a mason.
- Alternatives. A power-vent water heater may cost less than lining a long chimney.
Orphaned water heater liners
An orphaned water heater is one left alone in a chimney after the furnace moved to PVC. We measure draft at the hood with the house under worst-case conditions: exhaust fans and dryer running, doors closed. If it spills or drafts weakly, we install a liner sized to the water heater's input, connect it with a proper vent connector and cap it at the top of the chimney. Where the chimney is in poor shape or the run is long, a power-vent water heater can be the simpler answer, and we price both.
Liners for boilers on masonry chimneys
Standard-efficiency boilers still vent into masonry chimneys in many older homes, and a boiler replacement is a good moment to check the flue. An unlined or oversized chimney lets exhaust condense and eat the mortar joints from the inside, which shows up as white staining, loose bricks near the top, or debris at the chimney base. We inspect the flue, size a liner to the boiler's input, and install it with the right connector and cap so the new boiler vents cleanly for its whole life.
Chimney draft and condensation testing
Before anything is installed, we test. That means a draft reading at each appliance's vent with the house depressurized the way it is on a winter evening, a check for spillage at the draft hood, a carbon monoxide reading in the flue and the room, and a look at the chimney base and cleanout for debris and moisture. The test result decides the recommendation: no work, a liner, or moving the appliance to its own vent. You get the readings in writing either way.
How Minneapolis homes shape this job
Minneapolis guidance says that when a gas furnace or boiler is taken off an existing chimney, the installer must verify that any appliance still connected is sized to control flue gas condensation. Converting from an 80 percent furnace to a 90 percent or higher unit also moves the furnace to PVC flue pipe, adding one to three hours to the swap. We handle both halves together, so the water heater is never left behind untested.
What is included
What a liner installation includes
- Draft and spillage test before any work
- CO reading in the flue and room
- Flue inspection from the base and top
- Liner sized to the appliance input
- Vent connector replaced where needed
- Top plate and rain cap installed
- Insulation where the liner requires it
- Draft and CO retested after install
- Written results
Step by step
How a chimney liner job runs
- 1
Test draft and CO
Draft and spillage measured under worst-case conditions.
- 2
Inspect the flue
Chimney base, cleanout and crown checked for damage.
- 3
Recommend
No work, a liner, or a power-vent appliance, priced side by side.
- 4
Install
Liner fed down the flue, connected, insulated where required and capped.
- 5
Retest
Draft and CO measured again with the appliance running.
Questions we get on the phone
Chimney liner installation questions from Minneapolis homeowners
A draft test tells you. Spillage at the hood or weak draft means it needs attention.
The new furnace vents through PVC, leaving the water heater alone in a chimney sized for two appliances.
Sometimes. It depends on the chimney, the run length and where a side-wall vent can go.
Standard-efficiency boilers venting into masonry often do, especially after a replacement.
Most liner installs are done in a day.
More from this category
Related work we handle
Water Heater Installation
40 and 50 Gallon Gas Replacement and more.
About 40 and 50 gallon gas replacementFurnace Installation
Two-Stage and Variable-Speed Furnaces and more.
How we handle furnace installationFrom our guides: Getting a furnace ready for a Minnesota winter.
Find out if your chimney still works
Call to book a draft test. You get the readings before anyone recommends work.