Window Installation Service

Door Installation Service in O'Fallon, MO

Name: Keller Window & Door LLC
Address: O'Fallon, MO, US
Telephone: (314) 399-2001
Price range: $$$
Rating: 5.0

5 specialized services available

We install entry doors and patio doors built to last. Our installers have decades of experience fitting doors for proper alignment, weatherproofing, and smooth operation. Whether you need a new entry door, patio door replacement, or sliding glass door installation, we handle the job with care. We serve O'Fallon, Chesterfield, St. Peters, Wentzville, Wildwood, Ellisville, Creve Coeur, St. Charles, Ladue, Oakville, University City, Ballwin, Town and Country, and Maryland Heights.

Call (314) 399-2001

Professional patio door installation in a residential home

Door Installation Service

Serving O'Fallon, MO and the Florida Panhandle

Since 2015 Years Local

Free Estimates

5-Year Warranty

Services

Door Installation Service Services in O'Fallon, MO

A newly installed residential entry door on a single-family home in O'Fallon, Missouri, showing a clean frame fit and tight weatherstripping seal. The door is viewed from the front exterior, with the surrounding trim finished and flush against the siding.

Entry Door Installation

Keller Window & Door LLC installs entry doors for O'Fallon homeowners who want better security, efficiency, and curb appeal.

A properly sealed entry door reduces air leakage, helping lower heating and cooling costs year-round.
A new door with a solid core and updated hardware improves home security at the main point of entry.
Fresh entry door installation updates your home's exterior appearance and adds to resale value.

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A newly installed sliding glass patio door on the rear of an O'Fallon residential home, showing a clean frame fit and clear view to a backyard patio. The door hardware and threshold are fully finished with no visible gaps at the frame edges.

Patio Door Installation

Keller Window & Door LLC installs patio doors for O'Fallon homeowners who want better access, light, and efficiency.

Tighter weather seal reduces air leakage through O'Fallon's hot summers and cold winters
Smooth operation with correct threshold alignment and hardware fitting from day one
Reduced outside noise from a properly fitted door unit with no gaps at the frame

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A newly installed sliding glass door on the rear of a single-story O'Fallon, Missouri home, showing a clean frame, clear glass panels, and access to a backyard patio. The door is fully closed with the locking handle visible and the surrounding interior trim finished flush to the wall.

Sliding Glass Door Installation

Keller Window & Door LLC installs sliding glass doors for homeowners across O'Fallon, MO.

Tight frame seals block air infiltration through O'Fallon's cold winters and humid summers
Smooth sliding operation on properly set tracks reduces daily wear and extends door life
Secure multi-point locking adds a physical barrier at a common rear entry point

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A newly installed exterior entry door on a single-family home in O'Fallon, showing a clean frame, tight weatherstripping, and updated hardware. The door is photographed from the front of the home, with the surrounding trim freshly fitted by Keller Window & Door LLC.

Door Replacement

Keller Window & Door LLC provides professional door replacement services for homeowners in O'Fallon.

A properly sealed door reduces drafts and lowers heating and cooling costs year-round
A new door with a solid frame and updated hardware improves your home's security
Correct installation prevents sticking, warping, and air gaps caused by O'Fallon's seasonal temperature shifts

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A newly installed exterior front door on a single-family home in O'Fallon, Missouri, with a clean frame, tight weatherstripping, and a finished threshold visible at the base. A Keller Window & Door LLC installer checks the door swing alignment from the exterior.

Exterior Door Installation

Keller Window & Door LLC installs exterior doors for O'Fallon homeowners who want better security, efficiency, and curb appeal.

Tighter weatherstripping and threshold seals cut drafts and reduce heating and cooling loss
A properly fitted frame blocks moisture intrusion that leads to rot and mold over time
New exterior doors add visible curb appeal and support home resale value in O'Fallon

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We Serve

Why Choose Us

What sets us apart for Door Installation Service

Andersen Certified Contractor and Elite Certified distinction

Former Andersen employee owner with 30 years field experience

Factory-level installation precision and quality standards

Transparent pricing and clean workmanship

Appointment-only service for focused attention

Ready to get started?

Seen the work. Ready to talk about your project?

Call (314) 399-2001

FAQ

Common Questions About Door Installation Service in O'Fallon, MO

Straight answers to the questions homeowners ask before hiring a local contractor.

Do you install patio doors in St. Peters and surrounding areas?

Yes, we install patio doors and entry doors throughout the St. Louis area. Call 314-399-2001 to book an appointment.

What's included in a door installation?

We remove the old door, prepare the frame, install the new door, seal it properly, and test operation. Cleanup is included.

Can you replace just the door or do you need to replace the frame too?

We assess each door during the appointment. Sometimes we replace just the door. Other times the frame needs replacement for a proper fit.

How do I get a door installation quote?

Call us at 314-399-2001 to schedule an appointment. We'll assess your door and provide a clear scope.

Still have questions?

Call us directly. Real answers, no scripts.

Call (314) 399-2001

Client Reviews

What St. Charles County homeowners say.

5.0

11 Google reviews

Worked with us?

Leave a Review

I highly recommend Keller! The windows which I had replaced in my home are wonderful and I was very pleased with working with Keller. John Keller was very professional and honest in his recommendations for my windows as well as giving me a fair price for quality windows and workmanship. This is the only company to go with for window and door installation!

It was a pleasure working with John and his crew. They were helpful and did an excellent job with installation. I would use them again and recommend to anyone in need of a new patio door or other items they sell. Brenda Wilson

I love my new windows! What makes them even better is that the whole experience with Keller was very positive! I wish all contractors worked like John does. He was quick to reply for an estimate. His price was very fair. He came to install the windows when he said he would and he did what he said he would. (He actually did a little extra.😊)John and his crew were respectful, efficient, friendly. They protected my floors. They cleaned up after themselves. And they didn’t try to charge me extra for unforeseen issues. They wanted me to be happy and I AM. VERY. My new Andersen Windows are gorgeous and I would definitely recommend Keller Window and Door to my friends!!

John Keller and his team did an AMAZING job installing our new Anderson windows on our Sun porch! They were professional, friendly & courteous. John is extremely knowledgeable and knew exactly the right windows needed to match our historic neighborhood’s guidelines. John was wonderful to work with. I highly recommend Keller Window and Door!

John and his team were great from start to finish. He provided a no pressure sales quote and was responsive every time I reached out with questions. The installation process was quick, clean, and efficient. Great customer service from start to finish. Can recommend him enough.

Find Us

Proudly Based in O'Fallon, MO

Stop by, call, or book online — we're always nearby when you need us.

Phone

(314) 399-2001

Hours

Monday 8:30 AM - 4:30 PM
Tuesday 8:30 AM - 4:30 PM
Wednesday 8:30 AM - 4:30 PM
Thursday 8:30 AM - 4:30 PM
Friday 8:30 AM - 4:30 PM
Saturday Closed
Sunday Closed