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Beyond HVAC — Mississauga Heating & Air Conditioning
Tankless water heater repair Mississauga
MississaugaHot Water System SupplierTankless Water Heater Repair
Tankless Water Heater Repair · Mississauga, Ontario

Tankless Water Heater Repair in Mississauga

No hot water is never a good time. Our TSSA licensed technicians diagnose accurately, explain clearly, and fix it properly — so you're not dealing with the same issue again next month.

(437) 837-0777
Free Estimates
TSSA Licensed
Up to 10-Year Warranty
Google Reviews
5.0 Rated

A homeowner in Port Credit called us on a weekday morning — their Navien tankless unit was displaying an error code and producing no hot water. They'd had it for six years and it had never given them a problem. Our technician arrived that afternoon, identified a blocked condensate line and a dirty inlet filter that had triggered a fault shutdown, cleared both, reset the unit, and confirmed full operation before leaving. Total time on site: under an hour. The homeowner had hot water back by early afternoon and knew exactly what to watch for going forward.

Common Problems We Fix

Fast Diagnosis. Fixed Right.

Tankless water heaters are among the most reliable home appliances you can own, but when something goes wrong, the error codes and symptoms can feel confusing. Our technicians understand these systems inside and out.

We diagnose accurately, explain clearly, and fix it properly — so you're not dealing with the same issue again next month.

No hot water — ignition failure, gas supply, flow sensor
Inconsistent temperatures — scale buildup, flow sensor fault
Unit shuts off during use — venting, gas pressure, overheating
Error codes — we read and diagnose all major brands
Strange noises — scale on heat exchanger, ignition issues
Reduced hot water flow — blocked inlet filter or scale buildup
Tankless water heater repair Mississauga
Why It Matters

Why Professional Repairs Matter

Tankless water heaters are sophisticated appliances. Attempting DIY repairs risks voiding your warranty and creating genuine safety hazards.

Safety First

Tankless units involve gas burners, heat exchangers, flow sensors, control boards, and venting systems that all need to work together correctly. For gas-related issues, DIY repairs create genuine safety hazards. Our TSSA-certified technicians follow manufacturer guidelines on every repair.

Warranty Protected

When we're done, you have documentation of the service, your warranty remains intact, and the system has been tested to confirm it's operating safely and correctly. We provide service records for every repair visit.

Extends System Lifespan

A tankless water heater that's properly repaired and maintained can last 15 years or more. Addressing issues early — before a fault causes downstream damage to other components — is always less expensive than letting problems compound.

Customer Reviews

What Mississauga Homeowners Are Saying

Google Reviews
Trustpilot
Matthew Girgis
Matthew Girgis
1 month ago
on
Had a sudden leak in our furnace and received a quick response from Yuri. He sent one of his technicians, Michael, who came within a couple hours and was able to fix the issue at a reasonable price. Great experience with this company. Honest work and fair rates. Would use again.
Keenan Dion
Keenan Dion
1 month ago
on
I had a great experience with Beyond HVAC. They are very easy to deal with. I live in the Mimico/Park Lawn area and they were onsite within the hour. Michael resolved my heating issue for a great price, not having to replace the major components.
Nicole C
Nicole C
1 month ago
on
We are super happy to have found Beyond HVAC. We live in the South Riverdale / Leslieville area and were really impressed with the quality of his work. Yuriy is quick to respond, very professional and very knowledgeable. We had the tankless Navien NPE-240A2 installed. The installation was done neatly, all the venting and piping were organized well. During the installation, he also pointed out several issues with our previous setup that weren’t done correctly. He took the time to explain them and fixed everything properly, which gave us a lot of confidence that the system was installed the right way. I highly recommend him!!
Read more
Bradley
Bradley
2 months ago
on
Fantastic customer service. Fast friendly and efficient. Most importantly they are honest and very helpful.
Mark Leung
Mark Leung
2 months ago
on
Yuriy and Michael were consummate professionals - they laid out our options, provided clear communication and timely follow-ups. Could not be happier with their high service levels. Will likely be our go to for the foreseeable future. FYI: They replaced an aging water tank and serviced our furnace.
A H
A H
3 months ago
on
I came across Beyond HVAC while looking for a company that can perform routine tankless water heater maintenance and service in Etobicoke. I have used the installer before but he doesn't respond. I called in the morning and got a call back soon thereafter from Yuriy and set up an appointment for the next morning. I was thankful for the quick response time as well as the ability to set up an appointment relatively quickly. Michael came the next morning and was professional and courteous. He spent time to explain what he would do and after the service, he spent time to explain how it went and what I had to do (i.e. flush the pipes by turning on hot water at each faucet for 2-3 minutes). I would definitely use Beyond HVAC not only for tankless water heater maintenance but for other HVAC needs given my experience with them.
Read more
Paul D.
Paul D.
4 months ago
on
Beyond HVAC provided excellent service. We needed someone who provided service in the Etobicoke area to diagnose and repair our gas range. Yuriy responded to our requirements in a professional, prompt and customer focused manner. He sourced the part for us and went out of way to get it installed on Christmas Eve so that we could enjoy a Christmas dinner, for which we were very appreciative. He kept us fully apprised of the situation, following up at each stage of the service. His service was professional, complete and provided with excellent customer focus. We are completely satisfied. We will use him again for further service requirements.
Read more
Sam S
Sam S
4 months ago
on
Yuriy and Michael are very professional and knowledgeable. Michael was able to quickly diagnose and repair my malfunctioning furnace humidifier, and was happy to explain things as he worked. He went the extra mile to vacuum out some old renovation debris from the duct he was working on and cleaned up the work area when he was done. I'm glad to have a local HVAC professional I can trust!
Our Process

How We Diagnose & Repair

1

Accurate Diagnosis

We start by reading the unit's error codes, reviewing the symptom history, and performing a physical inspection of the key components — ignition, heat exchanger, flow sensor, venting, and gas supply. We identify the actual cause, not just the symptom.

2

Clear Explanation & Upfront Quote

Before any repair work begins, we explain what we found, what needs to be done, and what it will cost. No surprises. You decide whether to proceed with full information.

3

Same-Visit Repairs When Possible

We carry common parts for Rinnai and Navien units. Most repairs — clogged filters, condensate blockages, sensor replacements, ignition components — are completed on the same visit. We aim to restore your hot water before we leave.

4

Full Test & Documentation

After the repair, we run the unit through a complete hot water cycle, confirm proper operation, and document the service. You receive a record of what was repaired and confirmation that the system is operating safely.

Tankless Unit Not Working?

Call us or book online. We'll diagnose the issue, give you an upfront quote, and fix it properly.

Financing

Flexible Financing Available

Whether you need a straightforward repair or a more significant component replacement, we offer flexible financing options to help manage the cost.

We offer flexible financing through trusted lenders — including 0% interest for 12 months with approved credit. Spread the cost over time with monthly payment plans designed to fit any budget.

0% interest financing available
Deferred payment options (3 and 6 months)
Monthly payment plans for any budget
Quick approvals, apply in minutes
Explore Financing Options
Financeit 6 months deferral
0% financing availablePayment plans available
Financeit 0% interest equal payments
Why Choose Us

Your Trusted Hot Water Contractor in Mississauga

Accurate Diagnosis

We read error codes, inspect components, and identify the actual cause — not just the symptom. You get a clear explanation and an upfront quote before any repair work begins.

Fixed Right the First Time

We carry common parts for Rinnai and Navien units. Most repairs are completed on the same visit — no waiting for parts to be ordered while you're without hot water.

Warranty Stays Intact

Our technicians are TSSA-certified and follow manufacturer guidelines for every repair. When we're done, you have documentation of the service and your warranty remains valid.

Licensed & Certified

TSSA licensed and STO certified technicians on every job. Gas-related repairs performed to Ontario code by qualified professionals.

Equipment Partners

The Most Trusted HVAC Equipment
Brands for Your Etobicoke Home

As authorized contractors for leading HVAC manufacturers, we source and install only proven, high-efficiency equipment backed by manufacturer warranties.

Lennox HVAC equipment
Goodman HVAC equipment
Aprilaire HVAC equipment
Rinnai HVAC equipment
Navien HVAC equipment
Google Nest HVAC equipment
KeepRite HVAC equipment
Ecobee HVAC equipment
Frequently Asked Questions

Tankless Water Heater Repair in Mississauga

How long does tankless water heater repair usually take?

Most repairs take one to two hours on site. Simple issues like a clogged inlet filter or condensate blockage can be resolved in under an hour. More complex issues involving the heat exchanger, ignition system, or control board may take longer, particularly if a part needs to be ordered.

Why is my tankless water heater not producing hot water?

The most common causes are ignition failure, a gas supply interruption, a blocked vent, a tripped safety lockout, or a faulty flow sensor. The error code displayed on your unit, if any, gives us important diagnostic information. Call us and we can often get a sense of the likely issue before we even arrive.

Why does my tankless water heater shut off during use?

Sudden shutdowns during operation are most commonly caused by venting restrictions, gas pressure issues, scale buildup in the heat exchanger causing overheating, or a flow sensor that's reading incorrectly. Running the unit repeatedly through shutdowns can add stress to components — it's worth having diagnosed promptly.

Why is my tankless water heater displaying an error code?

Error codes indicate specific faults detected by the unit's diagnostic system — ignition failure, overheating, low water pressure, combustion sensor issues, and venting faults are among the most common. We're familiar with the fault codes across all major brands and can diagnose accurately from the code combined with a physical inspection.

Can a tankless water heater be repaired instead of replaced?

Yes, in most cases. The majority of tankless issues — ignition problems, clogged filters, sensor failures, scale buildup, and condensate blockages — are straightforwardly repairable. Replacement is typically only warranted for major heat exchanger failure in older units or when repair costs approach the cost of a new unit.

Does hard water affect tankless water heaters?

Yes. Hard water causes mineral scale to accumulate on the heat exchanger over time. This reduces efficiency, can cause overheating and error codes, and eventually restricts flow. Annual descaling maintenance is the most effective way to manage this — particularly in areas of Mississauga with harder water supply.

Do you repair all brands of tankless water heaters?

Yes. We service all major tankless water heater brands including Rinnai, Navien, Rheem, and others. Our technicians are familiar with the diagnostic systems and common failure points across all major manufacturers.

Get Started Today

Book Your
Tankless Repair

Contact Beyond HVAC today for tankless water heater repair in Mississauga. TSSA licensed, STO certified, and trusted by homeowners across the GTA.

(437) 837-0777