A commercial tankless water heater that stops delivering shuts down warewashing, handwashing and prep at the same time. In a foodservice operation that is not a comfort problem, it is a compliance problem, because a dish machine and a handwash sink both depend on hot water being there.
ProToCall installs, repairs and maintains commercial tankless water heaters. We have been servicing commercial kitchens and buildings since 2000, our phones are staffed 24 hours a day, seven days a week, and same-day service is often available. When we have capacity, we dispatch immediately.
Call 866-297-5082.
Commercial tankless water heater repair
Tankless units announce most faults through an error code, and the code narrows the diagnosis fast. What we see most often:
- Scale in the heat exchanger. The single biggest cause of tankless failure. Scale insulates the exchanger, the unit works harder for less output, and left long enough it damages the exchanger itself.
- Restricted flow. A fouled inlet screen or a partially closed valve can drop flow below the minimum the unit needs to fire, which reads as no hot water even though nothing has failed.
- Ignition and flame-sensing faults on gas units.
- Venting and combustion air problems, which are a safety issue and not a nuisance fault.
- Sensor and control board failures, including units that fire correctly but modulate wrong.
- Cold water sandwich, where short draws produce alternating hot and cold. Usually a sign of a sizing or recirculation design issue rather than a broken unit.
Why scale is the whole story
Everything in a tankless unit happens inside a narrow heat exchanger, and hard water leaves mineral deposits there every time it runs. Tank heaters tolerate scale for years because the tank has volume to spare. A tankless exchanger does not.
That is why descaling is not optional maintenance on this equipment. It is the maintenance. A unit on untreated hard water in a busy kitchen can lose meaningful output within a year, and the failure looks like a dying unit when it is actually a maintenance backlog.
Installation and replacement
Sizing a commercial tankless unit is a flow-rate calculation, not a like-for-like tank swap. The question is how many fixtures draw at once at peak, what the incoming water temperature is at the coldest time of year, and what temperature rise the unit has to deliver across that flow.
Get that wrong and the unit underperforms from day one, which is the most common complaint we are called to look at on equipment somebody else installed. Gas supply, venting and condensate handling all have to be right as well.
Maintenance
A commercial tankless unit needs descaling on a schedule set by your water and your demand, inlet filter cleaning, burner and flame-sensor inspection, venting and combustion checks, and a look at recirculation if the building has it.
ProCare 360 is ProToCall preventive maintenance, with scheduled service and asset tracking against your equipment, so descaling happens on a plan rather than after the output drops.
Where we service commercial plumbing
ProToCall commercial plumbing, including tankless water heater work, covers the major Texas metros: Dallas-Fort Worth, Houston and Austin.
Our commercial refrigeration, ice machine, cooking equipment, warewashing and commercial HVAC service covers a wider footprint. Call and we will confirm exactly what we cover at your address rather than guess.
Our technicians are employees rather than subcontractors, and service vehicles are GPS-equipped. Licensed: Texas plumbing RMP 44118. Texas HVAC TACLA113916C.
One vendor for the whole kitchen
Hot water sits between trades. The dish machine is warewashing, the heater is plumbing, and the building services around it are HVAC. Most operators run a different vendor for each and spend the outage working out whose problem it is.
ProToCall services commercial refrigeration, ice machines, cooking equipment, warewashing, commercial HVAC and commercial plumbing in our Texas plumbing markets. One call covers it.
Frequently asked questions
What is a commercial tankless water heater?
A commercial tankless water heater heats water on demand as it flows through the unit, instead of holding a heated reserve in a storage tank. Because there is no tank, there is no standby heat loss and no finite reserve to run out mid-service, but capacity is governed by flow rate rather than tank size.
How long does a commercial tankless water heater last?
Tankless units generally outlast tank heaters, and the difference is largely down to descaling. Scale is what kills them. A unit on hard water that is never descaled will fail early no matter how well it was installed.
Why is my tankless water heater not producing hot water?
The most common causes are scale buildup in the heat exchanger, a fouled inlet filter restricting flow, ignition or flame-sensing faults on gas units, or a flow rate below the minimum the unit needs to fire. An error code on the display narrows it quickly, so note it before you call.
How often should a commercial tankless water heater be descaled?
It depends on your water hardness and how hard the unit works, which is why descaling belongs on a scheduled program rather than a fixed guess. A kitchen on hard water needs it far more often than a low-demand application on treated water.
Can you size and install a replacement?
Yes. Sizing a commercial tankless unit is a flow-rate calculation, not a tank-size swap, and it has to account for simultaneous demand at peak. Undersizing is the most common reason a new unit disappoints.
Where do you service commercial plumbing?
ProToCall commercial plumbing, including tankless water heater work, covers the major Texas metros: Dallas-Fort Worth, Houston and Austin. Our commercial refrigeration, cooking equipment and HVAC service covers a wider footprint. Call and we will confirm coverage for your address.
Get your hot water back
Call 866-297-5082 to schedule a service visit. Our phones are staffed 24 hours a day, seven days a week, and same-day service is often available.