Flush and descale: the service tankless units need
Scale forms on the heat exchanger inside a tankless heater, and it can restrict flow and heat transfer. A flush circulates a descaling solution through the unit, dissolves the mineral buildup and rinses it out. It is the single most useful thing an owner can do for a tankless heater.
The Florence Water Consumer Confidence Report for 2025 does not list a hardness figure, and hardness differs by utility and well. The simplest way to know yours is to test the tap with a hardness kit or ask your utility for its annual water quality report. Where water is hard, flush intervals should be shorter.
Manufacturers publish flushing schedules in the manual, and we follow them. If your unit has never been flushed, tell us. The first service often removes years of scale.
Tankless symptoms and likely causes
Many service calls start with a symptom, not a model number.
| Symptom | Common cause | What we check |
|---|---|---|
| Lukewarm water | Scale on the heat exchanger, a flow sensor fault | Flush, then test temperature rise. |
| Brief cold burst between hot flows | Heater cycling at low flow | Minimum flow rate and recirculation settings. |
| Error code on the display | Ignition, venting, flow or sensor fault | Look up the code and test the part. |
| No hot water at all | No gas or power, a tripped safety | Gas supply, igniter and venting. |
| Low flow on hot only | Clogged inlet filter or scale | Clean the filter and flush. |
Installing a tankless heater
A tankless unit has different needs from a tank. A gas model usually needs a larger gas line, proper venting and a condensate drain if it is a condensing model. An electric model may need a heavy circuit that the panel can supply.
- Gas line size and meter capacity checked against the unit rating.
- Vent path and clearances to the outside.
- Isolation valves for future flushing.
- A condensate drain for condensing models.
- Flow rate matched to the number of fixtures that run together.
If you are weighing options, read water heater installation for a side-by-side view of tank and tankless choices.
Tankless service in Florence
Call us with the model and any error code. We will book a visit to flush, test and repair.
Call (480) 741-9332Swapping a tank heater for a tankless unit
Many owners ask whether they can switch. Often yes, but check these items first.
- Your gas line may need upsizing.
- The old flue may not suit the new unit.
- You may want a recirculation setup for fast hot water.
- Space on a wall near an exterior wall helps with venting.
If the old tank has failed, water heater replacement covers the emergency side.
Tankless repair, not just replacement
We repair and service tankless units instead of steering every call toward a new one. If a part is no longer made, or the unit is too far gone to be worth the money, we say that plainly and offer replacement.
What tankless service costs and what moves the price
You hear a price before work begins.
A flush costs less than a part repair or a new install.
Some parts are costly or hard to get on older units.
A long-neglected unit needs more time to descale.
New gas lines, venting and circuits add to the job.
Wall-mounted units are easy to reach. Attic units take longer.
Want your real number? Call (480) 741-9332 with the model and what the unit is doing.
Code note: gas, venting and manufacturer rules
Tankless heaters must follow the manufacturer's installation instructions as well as the plumbing and fuel gas codes adopted locally, which are usually based on the UPC, the IPC and the National Fuel Gas Code. Gas line size, vent material and clearances come from those documents, not from guesswork.
Tankless service around Florence
We service tankless units in town, at Anthem at Merrill Ranch and along Hunt Highway, and dispatch also covers Coolidge and San Tan Valley.
Tank heaters have their own faults, covered on our water heater repair page.
Questions about tankless water heaters in Florence
Follow the manufacturer schedule in the manual. In hard-water areas, a shorter interval is wise. If you have never flushed yours, schedule one now.
We connect pumps and hoses to isolation valves, circulate a descaling solution through the heat exchanger and rinse with clean water.
In most cases yes. Codes point to ignition, venting, sensor or flow faults, and we test the indicated part before replacing it.
It can if too many fixtures run at once for its rated flow. Sizing and the number of simultaneous uses matter.
It depends on your use and space. They save floor space and provide hot water on demand, but they cost more up front and need maintenance. We help you decide before you buy.
We service the common brands, and we tell you when you call if a particular model is outside what we can repair.