Tankless Water Heater Flushing in Lehi & Utah County
Utah's hard water scales tankless heaters fast. A yearly flush keeps your hot water steady and your heater running efficiently.
- Started in Lehi in 2021
- Tankless only
- Utah hard-water specialists
Flush My Tankless flushes and descales tankless water heaters across Lehi, Utah County and the southern Salt Lake Valley. Book a yearly flush and descale, get an error code sorted out, set up annual maintenance or replace a worn-out unit. A local tankless technician confirms your appointment and price when you book.
Request a time for your flush
Call to book, or send a time request. The technician serving your area confirms your appointment and price.
Call to Book a Flush(801) 515-4232- Call or request a time.
- A local tankless technician confirms your appointment and price.
- Flush, descale and inspection, about an hour.
- A reminder when next year's flush is due.
Why Utah's water is hard on tankless heaters
A tankless heater warms water as it rushes through a heat exchanger, a coil of narrow tubing. Calcium and magnesium in hard water come out as scale on those tube walls. Scale narrows the passages, makes the burner work harder and, left long enough, trips error codes and damages the heat exchanger.
- Efficiency. In a Battelle study for the Water Quality Association, gas tankless heaters on unsoftened water dropped from 80% to 72% efficiency before they had to be delimed.
- Lifespan. The Department of Energy says most tankless heaters last more than 20 years. Scale is one of the main things that cuts that short.
- Warranty. Rinnai's manual says damage caused by lime build-up is not covered. The other major brands exclude scale damage in similar language.
- Utah water. The USGS classifies water at more than 10.5 gpg as very hard. Navien's limit is 12 gpg; Takagi's is 7 gpg for a single-family home.
Tankless water heater services
Tankless flush and descale
The core job. The isolation valves are closed, a pump circulates vinegar or descaler through the heat exchanger, fresh water rinses it out and the inlet filter is cleaned. Done yearly, it keeps scale from building up in Utah's hard water.
Annual tankless maintenance
The flush plus the checks around it: filters, error history and any scale-prevention cartridge, on one visit. HomeGuide puts annual maintenance on a gas tankless at $150–$650.
Repair and error codes
No hot water, temperature swings or a code that won't clear. HomeGuide says minor repairs average $50–$300. The error code guide explains each brand's codes in the manufacturer's own words.
Replacement and installation
New units, like-for-like swaps and conversions from a tank heater. HomeGuide puts a tankless heater with installation at $1,400–$5,600, and Enbridge Gas's ThermWise program offers a $300 rebate on qualifying ENERGY STAR gas models.
Scale prevention
Softeners and scale-prevention systems slow how fast scale comes back, which matters most in the cities with the hardest water.
How much does a tankless flush cost in Utah?
HomeGuide puts a professional tankless flush at $150–$350. Angi lists $150–$250, with an average of $200. Those are typical national ranges, not a quote: the technician serving your area confirms your price when you book.
| Job | Typical cost | Source |
|---|---|---|
| Tankless flush | $150–$350 | HomeGuide |
| Annual maintenance, gas | $150–$650 | HomeGuide |
| Minor repair | $50–$300 | HomeGuide |
| New tankless, installed | $1,400–$5,600 | HomeGuide |
What moves the price of a flush: whether the heater already has isolation valves, how much scale has built up, and add-ons such as a scale-prevention cartridge. More in the tankless flush cost guide.
Our 5-step tankless flush
- Close the isolation valves
The hot and cold service valves cut the heater off from the house plumbing so the flush stays inside the unit.
- Connect the pump and descaler
Hoses run from the valve ports to a bucket with a small pump and vinegar or descaler.
- Circulate
Rinnai's manual says to circulate for at least 60 minutes; Navien's says at least 45 minutes.
- Rinse and clean the inlet filter
Fresh water flushes out the acid and loosened scale, and the cold-water inlet filter is cleaned.
- Restart and test
The valves are opened, air is purged, and the heater is fired and checked.
Signs your tankless needs a flush
- Hot water that surges and drops in the middle of a shower.
- Slower hot water at the taps than you used to get.
- A scale code. Rinnai LC means there is scale build-up in the heat exchanger and it needs to be flushed to prevent damage. Navien E016 means the heat exchanger is overheating. Rheem 1L means lime build-up has been detected in the heat exchanger. Noritz C1# is a service reminder for periodic maintenance, such as flushing scale from the heat exchanger.
- Noise. Bosch says scale can cause lower flow rates, A7 and E9 codes and boiling sounds.
- More than a year since the last flush.
How hard is your city's water?
Each city publishes its own water figures. Here is what several report, against Navien's 12 gpg limit:
| City | Hardness | Where the figure comes from |
|---|---|---|
| Highland | 14 gpg | city wells |
| Spanish Fork | 13.4–20.24 gpg | city water quality page |
| American Fork | 12.38 gpg | city softener setting |
| Provo | 10–15 gpg | city water report |
| Orem | 7–25 gpg | city water report |
| West Jordan | about 10.7 gpg | city report, converted from mg/L |
| Saratoga Springs | 8.3 gpg | city average |
| Lehi | Not published | Lehi's 2025 report lists no hardness figure |
How often each brand says to flush
| Brand | Manufacturer guidance |
|---|---|
| Navien | at least once a year |
| Rinnai | every 6 months, 1 year or 2 years (installer-selected) |
| Noritz | periodic flushing in hard-water areas |
| Takagi | checked once a year |
See all cities or the Utah hard water guide.
Started in Lehi in 2021
Flush My Tankless started in 2021, when Harrison Riehle began flushing tankless water heaters around Lehi. Utah's hard water was clogging heaters that should have lasted 20 years. Today, appointments are handled by local tankless technicians who follow the same process.
How booking works
- Call or request a time.
- A local tankless technician confirms your appointment and price.
- Flush, descale and inspection, about an hour.
- A reminder when next year's flush is due.
Tankless flushing questions
How often should a tankless water heater be flushed in Utah?
Navien recommends descaling at least once a year, and HomeGuide suggests every 6 to 9 months for homes with hard water. Most cities in Utah County and the southern Salt Lake Valley report hard or very hard water, so plan on at least a yearly flush unless your water is softened.
How long does a tankless flush take?
About an hour for the flush, descale and inspection. The descaler circulation alone runs at least 45 minutes on a Navien and at least 60 minutes on a Rinnai, according to their manuals.
How much does a tankless flush cost?
HomeGuide puts a professional tankless flush at $150–$350, and Angi lists $150–$250 with an average of $200. The technician serving your area confirms your price when you book.
Can I flush a tankless water heater myself?
Yes, if the heater has isolation valves and you follow the manual for your model. Navien warns that incorrect descaling could void the warranty if the heater is damaged, which is why many people book it.
Does skipping flushes void the warranty?
It can. Rinnai's manual says damage caused by lime build-up is not covered, and Navien, Noritz, Rheem and Bosch exclude scale damage in similar language.
Vinegar or descaler: which is better?
Both are used. Rinnai's manual calls for four gallons of undiluted, food-grade white vinegar; Noritz describes pure vinegar or a calcium, lime and rust product. Follow the manual for your model.
My heater shows an error code. Will a flush fix it?
If it is a scale code, such as Rinnai LC, Rheem 1L or Noritz C1#, usually yes. Codes for ignition, flame or venting need a technician to diagnose; a flush will not fix those.
Who does the work?
A local tankless technician who serves your area confirms your appointment and price, then does the flush, descale and inspection.
Book this year's flush.
Call to Book a Flush(801) 515-4232Sources
- Water Hardness | Highland City, UT (highlandut.gov)
- Spanish Fork City Drinking Water Quality page (Internet Archive capture, June 10, 2026) (web.archive.org)
- American Fork City FAQ: How hard is the water in American Fork? (americanfork.gov)
- Provo City Water Report 2025 (provo.gov)
- City of Orem Water Quality Report (Consumer Confidence Report, 2025 data) (orem.gov)
- Water Quality Consumer Confidence Report 2026 – West Jordan City (westjordan.utah.gov)
- Culinary Water | Saratoga Springs, UT (saratogasprings-ut.gov)
- How to Descale Tankless Water Heaters (Navien) (navieninc.com)
- Rinnai Tankless Water Heater Installation and Operation Manual (SENSEI, 100000773) (media.rinnai.us)
- Noritz Owner's Guide, Condensing Tankless Gas Water Heater (EZ111DV/EZ98DV) (support-legacy.noritz.com)
- Takagi On-Demand Water Heater Installation Manual and Owner's Guide, 110/310/510 models (listed for T-KJr2-IN/OS, 62S051) (takagi.com)
- Hardness of Water – USGS Water Science School (usgs.gov)
- Navien Installation Manual, NPE Condensing Water Heaters (NPE-A2/NPE-S2) (navieninc.com)
- Battelle finds water softeners aid energy efficiency, appliance life | Contractor Magazine (Mar 23, 2010) (contractormag.com)
- Tankless or Demand-Type Water Heaters | U.S. Department of Energy Energy Saver (archived Jun 30, 2026) (web.archive.org)
- How Much Does It Cost to Flush a Tankless Water Heater? (2026) | HomeGuide (homeguide.com)
- How Much Does It Cost to Flush a Water Heater? [2026 Data] | Angi (angi.com)
- How Much Does Tankless Water Heater Maintenance Cost? (2026) | HomeGuide (homeguide.com)
- How Much Does a Tankless Water Heater Cost? (2026) | HomeGuide (homeguide.com)
- ThermWise Appliance Rebates | Utah, Idaho & Wyoming | Enbridge Gas (enbridgegas.com)
- Navien User's Information Manual, NPE Condensing Water Heaters (NPE-A2/NPE-S2) (navieninc.com)
- Rinnai Tankless Water Heater Installation and Operation Manual (RE/VE Series, 100000722) (media.rinnai.us)
- Rheem High and Super High Efficiency Tankless Water Heater Troubleshooting Manual (AP21822, RTGH series) (files.myrheem.com)
- Bosch Service Bulletin TWH-G2-13: Descaling the Heat Exchanger (2400E/250SX/635ES) (bosch-homecomfort.com)
- How do I descale/flush the heat exchanger (Noritz Knowledge Base) (help.noritz.com)
- Water – City of South Jordan (sjc.utah.gov)
- WaterPro 2026 CCR for 2025 Water Year (waterpro.net)
- Jordan Valley Water Conservancy District – Consumer Confidence Report 2025 (jvwcd.gov)
- Water Source Transition – Herriman City Blog (Nov. 2025) (herriman.gov)