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Tankless Water Heater Problems- And How To Fix Them

Why is my tankless water heater not working ????????????????????????????????

  System Overloaded

 Mineral Build up or scale

 Flame failure message


Minimum flow rate

 Air Supply/ or Exhaust Blockage problems

No ignition flash code

So what went wrong, and how do we fix the problem.

My tankless water heater won’t start or ignite .

Ignition problems are a real hassle let me tell ya. Depending on the  model of tankless hot water heater you  may have, it probally will  display a code which reads  no ignition happening. There are a quite a lot of  reasons this might happen to your tankless water heater.

Number 1 ???   ,,  your gas supply to the unit, OK??  So before we move any further we want to make sure that firsrt off you dind not  run out gas.  

Lets verify that we have gas to the water heater.

The ignition may also fail if your gas supply or water valves are not in the on position, and all the way opened.

The Solution After checking your  gas and the water valves, it’s possible that your ignition control may have has failed ,, or they may be bigger problems hiding behind the problem. Most times, the first of 3  diagnostic steps will find your ignition problem–if you’re still stuck after that, it will be necessary to call technical support or a plumber to discuss the problem and possibly order replacement parts. My tankless water heater is growing something… 99% of the time, this is nothing we can’t fix: a mixture of calcium and magnesium that causes a scaly build-up in your tankless unit. If something else is growing in your tankless water heater, I’m afraid I can’t help you there. But seriously, mineral build-up is something to keep an eye on. All water heating systems will be exposed to large amounts of water on a daily basis. Depending on your area and local water supply, this can range from soft to hard water (or anything between); where ‘hard water’ describes water sources that are high in minerals, and tend to feel a bit sharper on your skin.

 The harder the water, the more likely your tankless water unit is to suffer from some significant mineral build-up. Mineral build-up can impair the functioning of your tankless unit, blocking the valves or otherwise making the components defunct. The Solution Again, it’s nothing we can’t fix. The good thing is, mineral build-up is one of the issues you can solve yourself, so long as you stay on top of it. I would suggest cleaning or flushing your unit every six months with a descaling cleanint kit. Many water heater brands will offer their own specific descaler, but in my experience, they work perfectly fine across brands. Flame Failure message This is rather similar to your ignition failure problem. 

Other causes that are more specific to flame failure issues are a lack of ventilation, a gas line that is too narrow or small to produce a consistent flame, or regulator failures. The Solution Again, be sure to cover the basics before contacting support. Make sure your propane tank is full (or that your gas bill has been paid this month!). Otherwise, check to see that the venting in your tankless unit hasn’t been blocked or stopped off (which can kill the flame). If these steps fail, then it may be time to reach out for help. My shower goes from hot to cold to hot again This is most common in family households–maybe you’ve noticed that it tends to happen when you shower right after another family member or spouse? 

There’s a simple explanation for it, and it is something of a downfall in many tankless water heating units. For those of you who don’t know what I’m talking about, it’s called the ‘cold water sandwich’ in water heater circles. Say a family member has just finished in the shower, and now you’re up. When you turn the shower on, you’ll be met with warm/hot water immediately (this is great, no waiting time), only to be followed by six or seven seconds of cold water again. What’s going on here? Well, it’s pretty simple really. Whoever showers first will need to put in the initial waiting time as the water in the unit heats up. Then, once it’s up and running, they will shower to their heart’s content and turn off the shower while the hot water is still blasting. 

This leaves some remaining hot water in your heating unit. So when you come along and turn on the shower, you will be hit with this remaining hot water, but if the unit has switched off then the heating process will need to start over… this means cold water will run through the unit once again, and you’ll be faced with the same initial waiting period that always happens. The Solution While tankless water heaters are much faster at heating water than tank models, they aren’t actually instantaneous. Hate to break it to you, but the six to seven seconds of cold water isn’t a flaw–it’s just part of how the system works, and there’s no ‘fixing it’. The solution, then, is to wait for the initial gush of warm water and cold water to pass by before hopping into the shower (unless you enjoy the brief cold rush!). My tankless water heater shuts down when too many taps are running This is also known as a system overload. Every tankless water heater will have a capacity–when it exceeds this figure, it may not be able to handle the load. This could happen when you are running multiple showers at once; using hot water through the kitchen tap while running a bath in the other room; or maybe just running two taps at once is enough for your unit to freak out. It can vary from your heating unit shutting down entirely, to simply not being able to produce enough hot water to satisfy all the necessary outlets. The Solution Depending on the severity of the issue, you can fix this by either: Limiting simultaneous use of showers/taps/water outlets; Upgrading your tankless water heater’s capacity; or Invest in a second heating unit.

If you are noticing this problem only on rare occasions, then the first solution will be enough to fix the issue on its own. Simply be aware of running more than one shower at the same time, and be sure to let your spouse know if you’re running hot water in the kitchen while they’re taking a shower! For more severe cases, you may be able to cover the load by upgrading your existing unit. Many modern tankless water heaters are able to provide ready-hot water for an entire household these days. But as another solution, you might simply invest in a second unit. This sounds a bit extreme (I thought the point of tankless water heaters was to save time and money), but if you follow the logic through you’ll find it is still worth your effort. By continuing with a water heater that doesn’t handle your household’s water needs, you will be frequently wasting water and gas as you wait for the unit to produce hot water where it’s needed. By installing a second unit, you will only use it when needed–it’s not a constant cost, just a one-time purchase which will save you in the long run. My tankless water heater’s air supply or exhaust is blocked You may have received a message on your unit telling you that the air supply is blocked–this may not have been very useful to you, though! When the error code is displayed, the machine is telling you that it’s having problems with combustion air or venting. The Solution The first thing to do is to check for obvious hazards or obstructions that might be blocking your vents. This could be something from your own household (a piece of laundry that found its way jammed in behind the unit) or something foreign like a wasps’ or rodents’ nest. Yuck, I know. Next, you’ll want to check your vent pipes; make sure they haven’t come loose, are connected properly to the unit and that they are free from punctures or holes. If you find they are punctured, you can try taping them up, but I would suggest ordering replacements. Lastly, you should double check with your product manual to be sure that it has been installed properly. If your tankless heating unit has been installed too close to other objects, this can cause unwanted blockage and the problem won’t go away–even if you fix everything else. The hot water shuts off in the middle of my shower If you’ve ever experienced this with your tankless water heater, I feel your frustration. It’s a painful moment to hear your heater switch off mid-shower, then feel the rush of cold water take hold. This is most common in older models of tankless water heaters–designs that were made ten or more years ago. It has to do with the minimum flow rate of your water heater being too high. Minimum flow rates describe how much water needs to be traveling through your tankless water heater in order for it to actually work; for it to receive the ‘heating signal’.

This problem is perhaps most likely to occur when you have an old school tankless unit combined with a newly installed, eco-friendly showerhead. These showerheads are great for saving water and helping the environment, but they may not be using enough water for your tankless unit to fire up. As a safety precaution, tankless water heaters shut off when there isn’t enough water running through the unit. Without enough cold water running through the unit, there is a big risk of overheating–which is why manufacturers tend to add in this safety precaution. Useful for not burning down the house–not so useful when you’re just trying to warm up in the shower. The Solution There are two ways to approach this problem, but sadly (unlike some of the others on this list) there is no simple solution.

The first pathway is to change your showerhead to something with a more substantial water flow. However, this would of course defeat the purpose of having installed an eco-friendly shower head in the first place. I mention this solution just in case your showerhead isn’t particularly eco-friendly, it’s just weak. Replacing a weak shower head with a stronger one may be enough to get more consistent water flowing through your tankless unit–so it won’t need to turn itself off. Pathway number two requires professional help. Ask a plumber to upgrade your unit, so that the minimum flow rate meets modern standards. 

Old units typically come in at ½ to ¾ gallons per minute (gpm) for minimum flow, while newer designs allow you to go as low as ¼ gpm.

We do service and repair and maintenance of Tankless hot water heater in Ontario

Mississauga, Oakville, Burlington, Milton, Clarkson, Streetsville, Port Credit, Erin Mills, Lorne Park. 

Applewood Central Erin Mills Churchill Meadows Clarkson Cooksville Creditview East Credit Erin Mills Erindale Fairview Hurontario Lakeview Lisgar Lorne Park Malton Meadowvale Meadowvale Village Mineola Mississauga Valleys Port Credit Rathwood Rockwood Village Sheridan Streetsville

We service and do repairs to 

  • Rinnai is by and large the best-selling tankless water heater in the U.S. Their gas-fired water heaters feature a commercial heat exchanger and are backed up with a comprehensive warranty.
  • Rheem offers gas, electric, and point-of-use tankless water heaters. They have a wide variety of offerings for residential and commercial use, and a U.S.-based customer service team for product questions.
  • Noritz provides water heaters that come with a low carbon footprint under the Eco Tough line, and commercial-level durability in the Pro Tough model. Their Value Solutions brand is specifically designed for smaller homes and warmer climates too.
  • American Water Heaters manufactures gas-powered tankless water heaters in condensing, indoor, and outdoor models. Many of their heaters are useful for smaller homes and apartments.
  • Navien tankless water heaters use stainless steel heat exchangers and are typically gas-fired. They too offer condensing and non-condensing water heaters.
  • Takagi was one of the earliest Japanese entrants to the North American tankless water heating marketplace 15 years ago. They still today offer a full line of gas-fired tankless water heaters.
  • Bradford White tankless water heaters are made under the EVERHOT and KWICKSHOT brand names; they offer whole-home and point-of-use systems.
  • Ruud has been a leader in water heaters since Edwin Ruud, the creator of tank heaters, founded the company in the late 1800s. Their gas-fired tankless offerings have a digital display and can be installed either indoor or outdoor.
  • Eccotemp excels at portable water heaters for the RV or campsite, with a particular strength in outdoor showers. They also offer residential water heaters for outdoors installation.
  • EcoSmart / Eemax combines the commercial and residential strength of Eemax with the strong environmental reputation of EcoSmart. The merged companies now offer a complete line of tankless water heaters for most any application.
  • Bosch is a pioneer in the gas-fired tankless water heater space; they’ve also developed some of the best indoor and outdoor water heating systems as a result of this innovation.
  • Stiebel Eltron tankless heaters are designed to be user friendly, safe, and efficient. They also happen to be some of the best single-point, multi-point, and whole-home water heating systems.
  • Drakken water heaters sold under the ADK iHEAT name are 99% efficient, more than 30% better than the most efficient storage tank water heaters.
  • A. O. Smith tankless water heaters are sold in both outdoor and indoor designs, with a maximum flow rate of up to 14.5 gallons per minute – more than enough for all but the heaviest of users.
  • Paloma Industries allows for users to change water temperature at the point of use, even in their whole-home systems, through a simple touchpad.