4-L Engineering Company Inc

4-L Engineering Company Inc operates out of Dallas, Texas, and focuses on HVAC work along with mechanical and plumbing support for multifamily buildings, commercial sites, and industrial facilities across the DFW Metroplex. The company has handled work in the area for more than 60 years, using that time to manage full facility needs rather than isolated fixes. Technicians there handle everything from routine maintenance to larger mechanical setups, keeping an eye on how air conditioning ties into the rest of a building's envelope. This approach lets them oversee multiple systems at once instead of sending separate crews for each problem that pops up in older properties.

They send crews for HVAC repairs, water heater problems, and plumbing backups, including emergency calls for clogged hall bathrooms and toilets in older high-rises along Turtle Creek. Charlie and Elmer have shown up for condo jobs to sort out both cooling and hot water issues, quoting prices up front and arriving during regular hours when requested. The same crews clear lines and restore flow on time, though some customers note the minimum charges start the moment a technician leaves home and can add up fast on smaller visits. These teams stick to scheduled arrivals and explain what broke before starting work on air conditioning units or drain lines that affect entire floors.

Reviewers often point to quick responses and clear explanations on what went wrong and how it got fixed, along with steady follow-through on jobs that keeps things running without repeat calls. At the same time, several mention surprise fees and high overall costs that lead to disputes, which drags down the average marks across speed, quality, price, and communication. DIRT Score 2.37 from 19 reviews on Finds.

DIRT Score = confidence-weighted rating across verified review platforms. How is this calculated? →

“Service was great! I’ve used them for both hvac and water heater issues for my condo. Charlie, Elmer and staff are very responsive and were transparent on everything from pricing, issues and solutions. I admit it’s definitely not cheap, but they do get the job done!”

“I live in one of the older high-rises on Turtle Creek and my hall bathroom and toilet were backing up. They offered me emergency service and quoted me the price as well as normal hours. I took them up on the normal hours and they arrived on time and cleared the backups. They called me on my cell when completed and the technician cleaned up after his work. Now, my master bathroom sink is backing up and I just scheduled another appointment. The receptionist, Terri, was quick to offer available times and I look forward to having this resolved. Yes, they are a bit pricey and it's worth it. They know my building quite well. As my father would say, "Money well-spent".”

“Warning! GET AWAY FROM 4-L - Do not trust this company after multiple issues last summer I managed to negotiate their fees because they never disclosed their origination fees. They will charge since your technician leaves home to get to you and then minimal charge is surreal, because this was a high rise they think they can fool the people and leave LOOSE WIRES INTENTIONALLY. Will be reporting them to the BBB since I just found multiple intentional issues now on my furnace right on time for the freezing weather. My tenant actually had to kick one of their guys from the job and they insisted in charging for that visit.”

“We’ve been using 4-L for the past 5 years, and they’ve been fantastic. They are reliable, and always deliver on time. The team is easy to work with, responsive, and professional. We highly recommend them to anyone looking for great service and dependable results! ☺️”

“Becareful with this company, they won’t give you an estimate or bid upfront. They will miss a day (apparently it takes three days to fix a single unit- they charge over a hundred dollars per labor hour) and they won’t communicate or let you know why they didn’t come to work on a unit until you call them. For a business this affects sales but worker apparently had an emergency. Overall terrible experience. They won’t let you know how much they’re going to charge you until the last second and surprise you with a couple thousand dollars. Hope they do better for other clients. Edit: just had to call another company because the unit has stopped working today and is leaking fluids. This is one week after the experience stated above with this company. I’m sure you are still looking forward to your payment. Also please do forward everything you proposed to send to email about estimations(with date) communication chains etc along with the time stamps. Also your worker didn’t show up the second day, though he was given confirmation the day before to go ahead and work on the single unit out of three for our store. There was no heads up for his no show and when I called your dispatch, she claimed worker had an emergency call to work elsewhere while the worker explained to me he was waiting for parts on same day.”