Abacus
Company Overview
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Abacus Plumbing was established by Master Plumber Alan O'Neill in 2003 with a singular aim: to create lifelong customers through exceptional service. Thanks to a customer-first philosophy, Abacus Plumbing has emerged as one of Houston's leading companies and has gained a solid reputation nationwide.
In February 2012, Abacus expanded its offerings to include Air Conditioning & Heating services. During its inaugural year, the Air Conditioning & Heating division served customers throughout Houston.
In September 2014, the company incorporated Electrical services into its offerings.
Abacus has gone above and beyond by maintaining a commitment to quality, customer-oriented care and continues to grow and succeed in the HVAC and Electrical fields. Residents of Houston need only contact one company for comprehensive plumbing, HVAC, and Electrical services.
Tom Tynan states: ""For more than two decades, I've known Alan O'Neill, and Abacus is far superior to any other plumbing business in Houston
Since 1977, Alan has been involved in the plumbing industry. Starting as a plumbing apprentice in his hometown of Dublin, Ireland. Alan is a licensed Texas Master Plumber. Alan is married to Linda and is a father of three. Alan loves spending time with his family and is a certified scuba diver.
“The calm and serenity of the underwater realm provide a refreshing escape from the daily grind,” says Alan He finds joy in supporting Houston's sports teams, with a special fondness for the Houston Dynamo.
Business Services
- Bathtub installation
- Bathtub repair
- Circuit breaker installation
- Circuit breaker repair
- Drain installation
- Drain repair
- Electric inspection
- Electric installation or replacement
- Electric panel installation
- Electric panel repair
- Electric repair
- Wire installation
- Wire repair
- Electric vehicle charging station installation
- Faucet installation
- Faucet repair
- Garbage disposal repair
- Gas line installation
- Gas line repair
- Generator installation
- Generator repair
- HVAC installation or replacement
- HVAC system repair
- HVAC system maintenance
- Light fixture installation
- Light fixture repair
- Outlet installation
- Outlet repair
- Plumbing inspection
- Plumbing installation or replacement
- Plumbing repair
- Sewer installation
- Sewer repair
- Shower installation
- Shower repair
- Sink installation
- Sink repair
- Toilet installation
- Toilet repair
- Water heater installation
- Water heater repair
- Water pipe installation
- Water pipe repair
Business Location & Hours
Mon: | Open 24 hours |
Tue: | Open 24 hours |
Wed: | Open 24 hours |
Thu: | Open 24 hours |
Fri: | Open 24 hours |
Sat: | Open 24 hours |
Sun: | Open 24 hours |
Recommended Customer Reviews

This review is based solely on the cost of repairs, which I am now finding out were way over market. Unfortunately, I am not a plumber, so do not know what a reasonable price is and needed the repairs done as I have house guests staying with me. I had a guest bathroom toilet that was wobbly, so called Abacus as I had used them a month or so ago when my HVAC drain was making a knocking noise. They were very nice and professional and prompt in providing service and it looks like the work was done in a professional manner.
However, the pricing is a totally different story. I was told the flanges needed replaced on both upstairs toilets. The cost to pull the toilet, replace the flange and then reset the toilet was $471.00 per toilet for a total of $942.00 for both. I was charged another $117.00 to Replace the Flapper or Tank Ball and then another $345.00 for a Toilet Tank Rebuild Minor, which is described as Flapper, Float or Chain, Minor Part. I don't know the difference between these two charges, but maybe there is a legitimate reason for both. I was then charged $352.00 to do an AC condensate clean at lav, which is apparently something the prior plumber that Abacus sent to fix this a month ago failed to do per discussions with today's plumber. This was after I told him that the noise was still continuing, but not as loudly. Lastly, I was charged $71.00 per 64 oz. bottle of BioOne Drain Treatment (a total of $142.00 for two bottles) because my drains were slow draining. I just saw that Home Depot sells the same brand and size bottle for $13.99 per bottle.
I hate feeling ripped off, but I still can't be sure if I was or not. However, most people I talked to after they left and most Google research on pricing also points to that. I thought the only fair thing to do was just to state the facts and list the prices. If you have an issue and need a plumber, I would just make sure you know what you are getting into, as I feel $2,073 to fix two toilets and unclog an HVAC drain was excessive.

hello called on 8 3 told Tenesha i herd from my assocition ws asked to check for ac drain pipe clog. fast forward 8 21 i call in the am about how they hide 250 minimum on the coupons i am told by kelly that the service request says low freon i correct her and reiterate no need to talk to tenant this is coming from Association concern poss clog drain pipe lo and behld after the dispatch called me 20 times wed am 8 21 with no regard thinking of my time . thinking i was the tenant when i clearly indicated i am the owner. theey sent me later in the day 8 21 a sheet that in no way addressed the reason i called which was poss drain pipe clog. and the tech Jay Rivas told my tenant to call if there are any issues
something clearly not legallu supported in texas lease or legal. on 8 22 GERALD a "manager" calls me and appears to agree that Jay should and could go back to check on what i called in Poss clog i hear nothing despite being told i would. On also on 821 Zondra tells me she will get back to me with an update nothing. on 8 23 when i call to check on all i m told the only way to get this resolved is to pay for the visit WELL LETS see when they offered to waive the service fee which i will not pay i did NOT get what i was supposed to so why would I pay? HOrrible. its clear there are many system breakdowns here.

I had a tree limb fall during a storm and take out my "weatherhead" late on a Saturday afternoon. After the power company and fire department gave me the all-clear, I had to find an electrician to come out to reattach the weatherhead to my home before CenterPointe would turn my power back on. I knew I would be paying a premium due to the after-hours, weekend call.
I rececived a prompt response from Abacus and they showed up about when they said they would. Fast forward 3 hours or so, and I signed off on the electronic invoice, which I paid for with my credit card.
When the Centerpoint guys came back, I commented that it had cost me nearly $1200 bucks. They asked "was your husband home?" When I said that he was travelling, they said, "yeah, you got ripped off". Then they showed me the pieces that the guy from Abacus had left behind, and said that he had reused the exisiting clamps to reattach the weatherhead.
I called Abacus the following week and asked for an itemized copy of the invoice. They sent me a copy of the exact same invoice I had been provided with.
I called back and explained that i wanted a detailed copy of my invoice. I was told that they would have to contact the manager of that department. I didn't really care who they got it from, but I wanted a detailed copy so that I could verify that the charges were reasonable and customary to what I should have been charged.
A week later, still no response. I called back and got the same story. A week later, STILL no response. I called again and was AGAIN told that they would have to get this information from the manager of that department. I explained that I had been told this same story repeatedly and that nobody had ever bothered to contact me back. I then said that I was going to dispute the charge with my credit card company until I got the itemized receipt I had asked for on numerous occassions. The woman I spoke with then became very rude, and as she hung up, I heard her say to someone "she says she's gonna dispute the charge".....
I then called my credit card company. During the hour I was on the phone with them, they had Abacus on the other line. Finally, they came back and asked that I give Abacus some time to respond to my CC company because they (ABACUS) suspected fraud. My company refunded the charge and I heard nothing back from either. Abacus did not send me the requested itemized bill.
Several months later, my credit card company reissueD the charge to my account. I never got the itemized receipt from Abacus. After a company tells you that THEY suspect fraud from one of their OWN employees or subcontractors, you tend to be a bit suspicous of their dealings. I'm not saying that they ripped me off or not. I AM saying that if they had nothing to hide, they should have produced the itemized receipt the first time I asked for it.
You decide for yourself if this is a company with which you want to do business.

I have never had a problem with Abacus Plumbing, Air Conditioning. Up until this moment...they were always efficient and up to par.
The first time I used Abacus was for my water heater. The line was leaking and they came in the next day and diagnosed the problem. It turns out the water heater was improperly installed. So, they have me the quote and although, I initially thought that is a very big quote to fix my water heater. I went through with the program. I needed the line fixed and wanted working plumbing.
Then, low and behold, less than 4 weeks later. I have an AC issue. My drip pan was just all screwed up...so I called Abacus again. Very nice installation guy called me and stated that in order to fix the problem we would basically need to re-install a plenum, French drain line and a new furnace. All issues I had known to be true. So, I told them, I would think it over. I figured, he wouldn't be lying to me of this system I needed. I also came to realize when they were quoting me...they were also quoting me for a new AC which was just replaced 3 years ago. But... anyone could make an honest mistake. But that saved me nearly $6000 NOT to replace my brand new AC unit. And they moved on with installing the rest of the unit or parts needed.
Fast forward...Houston heat hits and BAM!!! AC is not running properly. Turns out the capacitor is burnt out and we needed Freon/refrigerant. So...called Abacus to make a diagnose. There were some sort of leak in the system but the technician could not find the leak but was very confidant there was a leak and then quote me to replace the copper line within my system. Another $3000 bill. Mind you I have already paid this company nearly $12000. But the technician knew what he was talking about...but I wanted to make sure. So, he said he would come back to check the levels the next day and to confirm there was an actual leak in the system. Turns out they send a different technician. Now, I have already paid a deposit for this "new" system. And along with this new system they found an issue of the system they just installed. This is all becoming a nightmare at this point. The second technician comes in and says..nope everything looks good. At this point I was a bit confused...as they have not installed anything new...yet. So, I call the company to find out exactly what is going on. I get one Manager that is confused and was piecing together the information. Only to tell me yes you need the system. When I asked and told him the story...he reverted back and stated, "oh yea no." We need to check the system again. You may not need that whole install. Hallelujah someone is listening. So, they were suppose to send techs to fix the previous install first and check the levels to absolutely confirm the issue.
Well, as I was waiting patiently. No one shows and no one calls. I call back and they stated...oh my, I am so sorry. We were backed up in another job. "Someone" was suppose to call you. Same manager speaks to me and stated, I will have to reschedule you because the parts store is closed. I am at this point very frustrated. But..I said okay. But now it is not until Monday. Monday rolls around and I get another phone call from another manager stating they won't be able to send the guys out because they are stuck on a job. Wellllllll...at this point I am just overly frustrated. I said find me someone that will service my home, as I have worked with your scheduling team for five days now. They were suppose to call me back...NOPE. No call back. So...I call.
Only to get another manager that has no clue. Giving me another excuse why my job can't be complete. Never tells me when I will be rescheduled but that they were waiting on a part because they had to special order a part. I was like..you need to special order a drain pan. At this point I irate. I told him, they need to find me someone who actually knows about my project and find me a solution this evening....
Nope no call back again. I feel like I am working for Abacus at this point. But no manager can be reached at this time. And I still have no service or a service team to come out.
Next morning I wake up to a text...that states a technician will be coming...sooo now we have to scramble to who will be home while tech is here. Then it turns out they are re-installing the wrong equipment. I am now at the point waiting, yet for another phone call.
In my opinion, I am not sure if Abacus is looking out for their customers, but are trained to just be sales people versus actual technicians. Before I would of highly recommended them. Now, I am starting to think they are not such an honest company. Very frustrated and angry customer!!!!

I read the reviews and decided to give them a chance due to the 24/7 service. Our ac went out during the night Sunday so I called at 5am Monday to setup an appointment and they gave a window between 8-10am which was ok with me I understand it is their busiest time of the year. At 7:30 my pregnant wife was at home waiting and she asked me to home because it was already getting to hot for her. When I got home Mike (service tech) from Abacus contacted saying he would be there around 8am. He arrived on time and did his assessment, he came to me with the information in the photo, basically saying he could fix what he thought was wrong with it but couldn't tell me for certain that the unit would work that was $4k quote. He then explained that he air conditioner was old which I knew and it would be best to replace it. He then told me my ac options the first one being $25,000 and then the last one being $12,000 with two or three in between dropping in price about $5k each time. I talked it over with my wife and decided to call her brother who worked in the hvac industry. He said those quotes seemed high and he would come look at it soon. We told Mike we would think it over I paid the $50 service and he left. While waiting for my brother in law I called a few other places all of which quoted me from $5k to $7200 for an entirely new unit!!! My brother in law drives two hours from where he lives to check the unit and he replaced the capacitor ($30) because he had one on his truck. He unit fired up and works great. I understand they are operating a business and they make money from customers, but I feel as though they should focus on good service and honesty versus trying to up-sell and turning customers off and making them write these reviews potentially costing them business. My advice get a few other quotes from a few businesses before making a huge decision and wasting large amounts of money.

I am very sick with leukemia. Of all things my A/C quit when it was 102 degrees outside. I called Abacus Plumbing and Air Conditioning. They were able to come out within an hour. I was very happy with the repair and with the technician Carlos. He was very polite and knew his business. I have no idea what these complaints are about. I highly recommend this company. They are very professional!

My water heater would not heat up the water, so I called these guys to come to take a look. They told me the visit is $40, and if there is anything needs to be done, the technician will give me an estimate. So the technician came, look at it, pushed a button to light up the lit and then told me that it got turned off probably because it had no enough oxygen. So his suggestion was to put an extra fan on the roof, and he gave me the estimate. So far so good. Then he tells me that I need to pay about $200. I told him that for visit I had to pay $40 and I do not understand why now I have to pay $200. The answer was that because he lightened up the lit. Well, first of all it took just 5 seconds, so it must be part of the $40 I agreed to pay for the visit. Second, I did not agree on anything over $40, so why I have to pay for something I did not agree? At least he could tell me that this is going to cost me extra $160. This is called extortion. Unbelievable!!!

Well, I'm beginning to think only complainers post reviews. I had the most awesome experience from Jose to the installation team. I'm very happy with the service. Abacus financed my total work. At a low rate and I was financed before the work even began. I have *10 years of service charge free. My house was swept clean after the work was completed. The driveway also was clean. My neighbor was impressed, too. So I'm just saying, if you got great service from somebody---speak up.

I'm changing my review from 5 stars to 1 star. (Skip to the bottom if you want the TL;DR)
Initially I thought that Abacus was a trustworthy company. However, after multiple dealings with them arising from an AC coil replacement, I cannot recommend them.
In May 2018, my 4 year old Lennox AC unit stopped working. Abacus assessed the problem as a cracked coil. I paid over $2500 to replace it.
Over the course of the next 8 months, my house experienced abnormally high levels of humidity, to the point there was mildew growing around the vents. Abacus came out 3 separate times, I took time off of work, to meet them while they assessed the problem. On the first two occasions I was told that levels of 50-60% humidity are normal because "this is Houston."
All 3 times Abacus came out, I was told that my AC needed a complete replacement, costing close to $20,000.
Finally, fed up, I hired another AC company for a second opinion. I told them the history of the AC unit. It took them 5 minutes to locate the problem. You know what it was? There was no freon in my system.
The second opinion AC tech informed me that 12 pounds of freon doesn't just disappear, it was probably leaking out for the 8 months that I was complaining about high humidity.
When I called Abacus with the results, you know what they did? They immediately sent their "lead warranty technician" to rectify the situation. He explained that shortly after the coil was installed it must have cracked again. He had no explanation as to why 3 different Abacus technicians did NOT check if there was a freon leak.
In summary, Abacus charged me $2,500 for a new coil which they most likely did not properly install. After 3 separate visits, they told me that I would need to pay $20,000 for a new AC system. Once I got a second opinion from another AC company, Abacus immediately stopped bullshitting me and replaced the coil.
In the end, I paid $2,500 on an AC coil replacement that was improperly installed, was forced to listen to some conmen as to why I should pay them another $20,000, lost over 15 hours of work, and finally paid $100 for the second opinion and learned that Abacus was, at worst trying to scam me the entire time, and at best completely negligent by not checking the freon levels in my AC system.

"No disaster relief! I called to schedule service with Abacus early this morning at 7:00 to get my generators checked and running before the hurricane/Tropical Storm. They said no problem, they had 1 opening left between 12-3. I said great and then waited patiently for the technician to arrive. I was notified around 1:30 that they might not get to me today. I expressed that I really needed the service and would wait all day. I spoke to them 2 additional times checking in to see the status and they told me they were working on it. At 4:45 my phone died, which is exactly the time they called. I returned the call 5:00 pm and I was told a technician was on the way. I also received an email and that stated a technician was on the way and would arrive in 1/2 an hour. At 5:45 I called to check again and the dispatcher told me that they canceled my appt and rerouted the tech to another appt. It seems that they could care less about fairness and serving their customers that scheduled appointments and waited all day for service. Extremely disappointed!