Why Does My Tankless Water Heater Sometimes Go Cold Mid-Shower?
You are in the middle of a shower, nice and comfortable, and then out of nowhere—the water goes freezing cold. Nothing ruins a morning faster. We hear this complaint a lot from Tacoma homeowners with tankless water heaters. The good news? Most of the time, it is not a sign your heater is done for. It is usually something simple, like low water flow or a little mineral buildup inside the system. At 2 Sons Plumbing and Sewer Tacoma, we see it all the time and know how to get your hot water back on track.
Why Tankless Water Heaters Go Cold
When a tankless heater shuts off in the middle of a shower, a few common issues are usually to blame:
- Not enough flow: Tankless heaters need a certain amount of water moving through them. If it drops, the burner shuts off.
- Scale buildup: Minerals inside the unit can block sensors and slow everything down.
- Settings off: If the temperature isn’t dialed in around 120°F, the system may not behave the way you expect.
Most of these are small problems that can be fixed without replacing the unit.
Quick Fixes You Can Try
A couple of simple steps may solve it:
- Turn on another faucet. Adding flow can keep the system engaged.
- Check the temperature. Make sure it’s set around 120°F—hot enough for comfort, safe enough for the system.
- Flush the unit. Once a year, use a descaling kit to clear out mineral buildup.
- Regular descaling makes a big difference—it keeps the heat steady and helps your unit last longer.
When to Call a Plumber
Sometimes the fixes above won’t cut it. Give 2 Sons Plumbing and Sewer Tacoma a call at (206) 487-1757 if:
- You see error codes on the display.
- There’s a gas smell near the heater.
- The water still cuts out even after flushing the system.
Those are signs of a bigger issue, like a failing valve or control board. That’s when you need professional tools and know-how.
What It Usually Costs
Here’s what most Tacoma homeowners can expect:
- Descaling service: $250–$500
- Valve or control repairs: Cost depends on the part and labor
Fixing things early almost always saves money compared to waiting until the unit stops working altogether.
Why Call Local Experts
Tankless water heaters are great—compact, efficient, endless hot water when they’re working right. But they’re also a little more sensitive than standard tanks. At 2 Sons Plumbing and Sewer Tacoma, our plumbers work on them every week. We know the quirks, we know the brands, and we’ll explain the fix in plain language so you’re not left guessing.
Keep the Hot Water Coming
Don’t let cold surprises keep ruining your showers. Call 2 Sons Plumbing and Sewer Tacoma at (206) 487-1757, and we’ll send a plumber who knows tankless systems inside and out.
One call and you can stop shivering, stop guessing, and get back to showers that stay hot from start to finish.
Amber Rhodes
3 weeks ago
I had a great experience with 2 Sons Plumbing and Sewer. I scheduled an appointment online last night, and they called me first thing this morning. Natalie was so kind and even offered me an earlier appointment that same day, which I really appreciated.
Justin came out and was friendly, professional, and honest. He gave me a fair estimate for the repair I needed and also provided estimates for a few additional code-related fixes that may need to be addressed in the future. I never felt pressured to approve any extra work, which I really appreciated.
From scheduling to the service visit, the entire experience was easy and professional. I would definitely use 2 Sons Plumbing and Sewer again and would happily recommend them to others!
Justin came out and was friendly, professional, and honest. He gave me a fair estimate for the repair I needed and also provided estimates for a few additional code-related fixes that may need to be addressed in the future. I never felt pressured to approve any extra work, which I really appreciated.
From scheduling to the service visit, the entire experience was easy and professional. I would definitely use 2 Sons Plumbing and Sewer again and would happily recommend them to others!
Amber Rhodes
3 weeks ago
I had a great experience with 2 Sons Plumbing and Sewer. I scheduled an appointment online last night, and they called me first thing this morning. Natalie was so kind and even offered me an earlier appointment that same day, which I really appreciated.
Justin came out and was friendly, professional, and honest. He gave me a fair estimate for the repair I needed and also provided estimates for a few additional code-related fixes that may need to be addressed in the future. I never felt pressured to approve any extra work, which I really appreciated.
From scheduling to the service visit, the entire experience was easy and professional. I would definitely use 2 Sons Plumbing and Sewer again and would happily recommend them to others!
Justin came out and was friendly, professional, and honest. He gave me a fair estimate for the repair I needed and also provided estimates for a few additional code-related fixes that may need to be addressed in the future. I never felt pressured to approve any extra work, which I really appreciated.
From scheduling to the service visit, the entire experience was easy and professional. I would definitely use 2 Sons Plumbing and Sewer again and would happily recommend them to others!
Jackie Johanson
4 weeks ago
⭐⭐⭐⭐⭐
I had a project that required a quick turnaround for some temporary top-out plumbing, and Two Sons Plumbing was incredibly responsive from the start. They came out quickly to provide a quote and, even during what I know is their peak season, they prioritized getting my project scheduled. That level of customer service was greatly appreciated.
The quote was a bit of sticker shock, but that’s simply the reality of the Seattle market—not a reflection of their service. What really stood out was that the same person who came out to provide the estimate also completed the work. It meant I didn’t have to explain everything twice, and we’d already built a level of trust before the job even started.
The quality of the work was excellent, and they even went above and beyond by replacing a damaged toilet lid at no extra charge. Small gestures like that make a big difference.
If you’re looking for a fast, reliable plumbing company that does quality work and takes great care of its customers, I’d definitely recommend Two Sons Plumbing.
I had a project that required a quick turnaround for some temporary top-out plumbing, and Two Sons Plumbing was incredibly responsive from the start. They came out quickly to provide a quote and, even during what I know is their peak season, they prioritized getting my project scheduled. That level of customer service was greatly appreciated.
The quote was a bit of sticker shock, but that’s simply the reality of the Seattle market—not a reflection of their service. What really stood out was that the same person who came out to provide the estimate also completed the work. It meant I didn’t have to explain everything twice, and we’d already built a level of trust before the job even started.
The quality of the work was excellent, and they even went above and beyond by replacing a damaged toilet lid at no extra charge. Small gestures like that make a big difference.
If you’re looking for a fast, reliable plumbing company that does quality work and takes great care of its customers, I’d definitely recommend Two Sons Plumbing.
Jackie Johanson
4 weeks ago
⭐⭐⭐⭐⭐
I had a project that required a quick turnaround for some temporary top-out plumbing, and Two Sons Plumbing was incredibly responsive from the start. They came out quickly to provide a quote and, even during what I know is their peak season, they prioritized getting my project scheduled. That level of customer service was greatly appreciated.
The quote was a bit of sticker shock, but that’s simply the reality of the Seattle market—not a reflection of their service. What really stood out was that the same person who came out to provide the estimate also completed the work. It meant I didn’t have to explain everything twice, and we’d already built a level of trust before the job even started.
The quality of the work was excellent, and they even went above and beyond by replacing a damaged toilet lid at no extra charge. Small gestures like that make a big difference.
If you’re looking for a fast, reliable plumbing company that does quality work and takes great care of its customers, I’d definitely recommend Two Sons Plumbing.
I had a project that required a quick turnaround for some temporary top-out plumbing, and Two Sons Plumbing was incredibly responsive from the start. They came out quickly to provide a quote and, even during what I know is their peak season, they prioritized getting my project scheduled. That level of customer service was greatly appreciated.
The quote was a bit of sticker shock, but that’s simply the reality of the Seattle market—not a reflection of their service. What really stood out was that the same person who came out to provide the estimate also completed the work. It meant I didn’t have to explain everything twice, and we’d already built a level of trust before the job even started.
The quality of the work was excellent, and they even went above and beyond by replacing a damaged toilet lid at no extra charge. Small gestures like that make a big difference.
If you’re looking for a fast, reliable plumbing company that does quality work and takes great care of its customers, I’d definitely recommend Two Sons Plumbing.
Brad Poirier
2 months ago
Had a great experience with 2 Sons Plumbing and Sewer and the representative they sent, Jake. They did a fantastic job communicating through email, text, and calls, sending reminders when the appointment was and who their representative was, and when he would arrive. Jake did a wonderful job hunting done where the leak was coming from and explaining the options I had for getting the leak repaired. When he left he emailed my receipt, pictures he had taken of my water lines under the house, and the options I could use to compete locating and repairing the leak. Highly recommend them. A very professional outfit.
Brad Poirier
2 months ago
Had a great experience with 2 Sons Plumbing and Sewer and the representative they sent, Jake. They did a fantastic job communicating through email, text, and calls, sending reminders when the appointment was and who their representative was, and when he would arrive. Jake did a wonderful job hunting done where the leak was coming from and explaining the options I had for getting the leak repaired. When he left he emailed my receipt, pictures he had taken of my water lines under the house, and the options I could use to compete locating and repairing the leak. Highly recommend them. A very professional outfit.
Jennifer Suemnicht
3 months ago
I asked some of my real estate colleagues who people have been using for plumbing repairs lately and several said “2 Sons”! So friendly and responsive. Came out right away for an estimate, had the best follow up, came in with the best price, and got me on the schedule and got the work done on the very next day! Everyone I spoke with was friendly and fantastic! Highly recommend!
Jennifer Suemnicht
3 months ago
I asked some of my real estate colleagues who people have been using for plumbing repairs lately and several said “2 Sons”! So friendly and responsive. Came out right away for an estimate, had the best follow up, came in with the best price, and got me on the schedule and got the work done on the very next day! Everyone I spoke with was friendly and fantastic! Highly recommend!
Katy Garner
5 months ago
We had a mystery leak per our meter reading. Riley and Riley saved the day. They promptly discovered the issue, resolved and repaired our pipes in one service call. They were quick, thorough and entirely delightful. They took the time to talk me through the job. I felt heard, safe and comfortable with the two of them in my house. For my next plumbing disaster I hope to get ‘The Riley’s’; but know, whoever comes will be excellent. Thanks 2 Sons!
Katy Garner
5 months ago
We had a mystery leak per our meter reading. Riley and Riley saved the day. They promptly discovered the issue, resolved and repaired our pipes in one service call. They were quick, thorough and entirely delightful. They took the time to talk me through the job. I felt heard, safe and comfortable with the two of them in my house. For my next plumbing disaster I hope to get ‘The Riley’s’; but know, whoever comes will be excellent. Thanks 2 Sons!
Aaron Sutter
5 months ago
2 Sons are my go to plumbers and I recommend them to friends and family looking for a recommendation.
2 Sons had my tenant's water heater replaced in the same day I called them! Justin and his apprentice were awesome! This wasn't a "quick" replacement in the garage - they had to figure out how to squeeze in the water heater through a tight crawl space on their hands and knees under furnace ducting.
Justin was knowledgeable and helpful in troubleshooting different replacement scenarios. He was kind and patient with my number of questions. He never once complained to me about the undesirable placement of the water heater under the house. My tenant even commented to me how kind Justin was to her.
Thank you for making this a quick and easy fix!
2 Sons had my tenant's water heater replaced in the same day I called them! Justin and his apprentice were awesome! This wasn't a "quick" replacement in the garage - they had to figure out how to squeeze in the water heater through a tight crawl space on their hands and knees under furnace ducting.
Justin was knowledgeable and helpful in troubleshooting different replacement scenarios. He was kind and patient with my number of questions. He never once complained to me about the undesirable placement of the water heater under the house. My tenant even commented to me how kind Justin was to her.
Thank you for making this a quick and easy fix!
Aaron Sutter
5 months ago
2 Sons are my go to plumbers and I recommend them to friends and family looking for a recommendation.
2 Sons had my tenant's water heater replaced in the same day I called them! Justin and his apprentice were awesome! This wasn't a "quick" replacement in the garage - they had to figure out how to squeeze in the water heater through a tight crawl space on their hands and knees under furnace ducting.
Justin was knowledgeable and helpful in troubleshooting different replacement scenarios. He was kind and patient with my number of questions. He never once complained to me about the undesirable placement of the water heater under the house. My tenant even commented to me how kind Justin was to her.
Thank you for making this a quick and easy fix!
2 Sons had my tenant's water heater replaced in the same day I called them! Justin and his apprentice were awesome! This wasn't a "quick" replacement in the garage - they had to figure out how to squeeze in the water heater through a tight crawl space on their hands and knees under furnace ducting.
Justin was knowledgeable and helpful in troubleshooting different replacement scenarios. He was kind and patient with my number of questions. He never once complained to me about the undesirable placement of the water heater under the house. My tenant even commented to me how kind Justin was to her.
Thank you for making this a quick and easy fix!
Oksana Naidu
5 months ago
Highly recommend 2 Sons. We had a leak in the master bath due to some malfunctioning fixtures and needed to install shut off valves on the hot and cold water lines to prevent further leaks while we waited on the faulty part replacements to be delivered. It was a treat to work with a professional and honest plumbing company that also does quality work. A great experience from first call to post-completion follow ups. Marcos, who was assigned to our job, was just awesome - thorough, efficient, knowledgeable, professional, courteous and helpful. He took his time to fully assess the issue, provided great options and then quickly repaired the problem. Thanks so much for great service in a stressful situation.
Oksana Naidu
5 months ago
Highly recommend 2 Sons. We had a leak in the master bath due to some malfunctioning fixtures and needed to install shut off valves on the hot and cold water lines to prevent further leaks while we waited on the faulty part replacements to be delivered. It was a treat to work with a professional and honest plumbing company that also does quality work. A great experience from first call to post-completion follow ups. Marcos, who was assigned to our job, was just awesome - thorough, efficient, knowledgeable, professional, courteous and helpful. He took his time to fully assess the issue, provided great options and then quickly repaired the problem. Thanks so much for great service in a stressful situation.
Happy Lemon
5 months ago
We had an outstanding experience with this company! They provided incredibly fast, careful, and professional service for our commercial business. From start to finish, their customer service was absolutely excellent-responsive, friendly, and truly attentive to our needs.
A special thank you to our technician, ADAM, who did an exceptional job fixing our clogged hand sink. He was knowledgeable, efficient, and extremely professional & polite. He quickly resolved it with great skill and attention to detail.
Highly recommended!
A special thank you to our technician, ADAM, who did an exceptional job fixing our clogged hand sink. He was knowledgeable, efficient, and extremely professional & polite. He quickly resolved it with great skill and attention to detail.
Highly recommended!
Happy Lemon
5 months ago
We had an outstanding experience with this company! They provided incredibly fast, careful, and professional service for our commercial business. From start to finish, their customer service was absolutely excellent-responsive, friendly, and truly attentive to our needs.
A special thank you to our technician, ADAM, who did an exceptional job fixing our clogged hand sink. He was knowledgeable, efficient, and extremely professional & polite. He quickly resolved it with great skill and attention to detail.
Highly recommended!
A special thank you to our technician, ADAM, who did an exceptional job fixing our clogged hand sink. He was knowledgeable, efficient, and extremely professional & polite. He quickly resolved it with great skill and attention to detail.
Highly recommended!
Louisa
5 months ago
Trung our tech and his apprentice Cole did a fantastic job yesterday. They worked tirelessly to replace our old CPVC pipes, install our new shower, and replace our kitchen sink. The job had a multitude of delays due our pipes not being plumb and some extra wall demo. They worked for at least 13+ hours yesterday and left our home at 11 pm. Trung wanted to ensure that we didn't have our water off longer than necessary. We could not be more thankful and grateful for their efforts in the rough in for our bathroom remodel. We look forward to having them back to install the shower/ tub combo, new bathroom faucet, and new toilet with a bidet seat. Trung always went out of his way to explain what was going on and helped us make informed decisions about our home. This is our 3rd or 4th time using 2 Sons and we couldn't recommend them more!
Update: Trung was extremely great with the final install! Unfortunately, there was a few mishaps with not communicating the right color of the shower/ tub combo and the hole for the toilet pipe not being wide enough for the toilet flange. Trung really went above and beyond to ensure we got the right parts and to cut the tile as best he could for the toilet to fit. He even had to double check our toilet because he thought he heard a leak. He even was able to replace our drain stopper and recommended a solution for making the tub drain match!
Update: Trung was extremely great with the final install! Unfortunately, there was a few mishaps with not communicating the right color of the shower/ tub combo and the hole for the toilet pipe not being wide enough for the toilet flange. Trung really went above and beyond to ensure we got the right parts and to cut the tile as best he could for the toilet to fit. He even had to double check our toilet because he thought he heard a leak. He even was able to replace our drain stopper and recommended a solution for making the tub drain match!
Louisa
5 months ago
Trung our tech and his apprentice Cole did a fantastic job yesterday. They worked tirelessly to replace our old CPVC pipes, install our new shower, and replace our kitchen sink. The job had a multitude of delays due our pipes not being plumb and some extra wall demo. They worked for at least 13+ hours yesterday and left our home at 11 pm. Trung wanted to ensure that we didn't have our water off longer than necessary. We could not be more thankful and grateful for their efforts in the rough in for our bathroom remodel. We look forward to having them back to install the shower/ tub combo, new bathroom faucet, and new toilet with a bidet seat. Trung always went out of his way to explain what was going on and helped us make informed decisions about our home. This is our 3rd or 4th time using 2 Sons and we couldn't recommend them more!
Update: Trung was extremely great with the final install! Unfortunately, there was a few mishaps with not communicating the right color of the shower/ tub combo and the hole for the toilet pipe not being wide enough for the toilet flange. Trung really went above and beyond to ensure we got the right parts and to cut the tile as best he could for the toilet to fit. He even had to double check our toilet because he thought he heard a leak. He even was able to replace our drain stopper and recommended a solution for making the tub drain match!
Update: Trung was extremely great with the final install! Unfortunately, there was a few mishaps with not communicating the right color of the shower/ tub combo and the hole for the toilet pipe not being wide enough for the toilet flange. Trung really went above and beyond to ensure we got the right parts and to cut the tile as best he could for the toilet to fit. He even had to double check our toilet because he thought he heard a leak. He even was able to replace our drain stopper and recommended a solution for making the tub drain match!
Kathy Cook
5 months ago
I have to say Bob was amazing!!! I had a clogged drain in my kitchen sink. Bob came in and took every precaution to be neat & clean. He explained to me what he was going to do and gave me the pricing and I agreed and he got to work. He was super kind and polite and fixed my drain issue. He was a pleasure to work with. I would highly recommend using 2 Sons!
Kathy Cook
5 months ago
I have to say Bob was amazing!!! I had a clogged drain in my kitchen sink. Bob came in and took every precaution to be neat & clean. He explained to me what he was going to do and gave me the pricing and I agreed and he got to work. He was super kind and polite and fixed my drain issue. He was a pleasure to work with. I would highly recommend using 2 Sons!
Services Provided:
PLUMBING:
SEWER :