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Why Is My Tankless Water Heater Not Heating?

You depend on your tankless water heater for cooking and cleaning, so it can be a significant inconvenience when it stops working. There are many causes of water heater failure, and promptly identifying the precise cause of your system’s hiccup is crucial. The following are some of the most common problems and the reasons why your water heater has stopped supplying the water your home needs.

Inconsistent Heating

Inconsistent operation is often because you are pushing the unit to supply more hot water than it has the capacity to provide. This can occur if you try and run the dishwasher, washing machine, shower, or cook all at the same time. Try ceasing some or all of the operations — this will usually resolve the problem.

No Hot Water

No hot water is a sign of a more serious issue. If the tankless water heater stops supplying any hot water, it can be because of a mechanical fault or problems with the gas supply. Start by inspecting the vent/air intake for any blockages and remove any you find. You will also want to look at the burners and ignitors. If they are dirty, they will need to be cleaned.

If you have hard water, it could be plugging the heat exchanger. And if that isn’t the issue, it could be because the gas supply is blocked. In either case, these last two causes will require the assistance of a certified plumber to resolve.

Water Suddenly Stops

If the hot water suddenly stops while you are taking a shower, running the dishwasher, filling a pot, etc., it is usually because your minimum flow rate is too high. This is a common problem with older tankless hot water heaters. Your minimum flow rate is a set minimum amount of hot water the unit needs flowing through the system.

If the minimum flow rate is too low, then your system will shut down as a safety precaution. If it is a continual problem, you may need to upgrade your tankless water heater to a newer version with a lower minimum flow rate.

System Won’t Turn On

If you have an electric tankless hot water that simply won’t turn on, take a look at the breaker box. It may be that you have blown a fuse and need to replace it. Conversely, if you have a gas-fueled tankless water heater, make sure the gas supply is switched on.

Discolored Water

If you have discolored water that doesn’t look or smell quite right, there is likely something growing within your pipes or within the tankless water heater. This can occur as minerals within the line buildup, and while it is frustrating, it is also easily resolved. Simply flush your system with some vinegar and/or a descaling solution. This will remove the mineral deposits quickly and effectively.

Frequent Repairs

Are you experiencing reoccurring issues with your tankless water heater? One week, it’s not supplying enough hot water, the previous week, it wasn’t supplying any, and the week before that, the breaker kept tripping. If you have frequent problems with an older water heater, it’s likely time to replace it. Most systems operate for 15 to 20 years, after which point, it’s usually best to replace rather than continue paying for repairs.

Do you have more questions about tankless water heater systems? Contact the experts at Penguin Air, Plumbing & Electrical by calling (480) 747-6800. We will give you the answers you need and the professional advice you can depend on!