MVP Plumbing installs and services tankless water heaters in Baytown, Mont Belvieu and across the Houston area. We sell and install State, Navien and Noritz, and we will service other brands including Rinnai. All work is performed under Master Plumber License MPL 38224.
If your tankless has stopped making hot water, is throwing a fault code, or you are weighing up a tankless conversion, call 832-334-2836 and we will tell you plainly what is involved.
The thing nobody tells you before you buy: parts
Most tankless advice online argues about efficiency ratings and flow rates. In practice, the difference you will actually feel is how long you go without hot water when something fails.
We sell and install State, Navien and Noritz. For those, we diagnose the unit ourselves, call for the part, and it is usually somewhere in the Houston area — worst case a day.
We will happily service a Rinnai someone else installed, but the parts come from further out. On the last one that meant three days without hot water instead of one.
Worth knowing before you buy: a cheap unit that nobody in Houston stocks parts for means a cold week when it fails. The purchase price is the part of the decision you see. The parts pipeline is the part you feel.
A recent job — Rinnai warranty repair in Mont Belvieu
Job notes · Mont Belvieu, residential
The customer had hot water and then suddenly did not. The fault turned out to be the thermal fuse.
Rinnai handles warranty work through their own service department, so we got on a video call with their technician, went through the unit with them on camera, and they made the call on what was wrong and shipped the part. We fitted it.
Parts took two days to arrive, so the customer was without hot water for three days.
We handle the manufacturer, you do not
If your tankless is still under warranty, the manufacturer decides what gets replaced — not us. That is how warranty work is structured across the industry, and it is not something a plumber can shortcut.
What we can do is take that job off you. We get on the video call with their technician, walk them through the unit, get the part approved and shipped, and fit it when it lands. You do not sit on hold trying to describe a fault you cannot see, and you do not have to prove anything to a call center.
Tankless installation
A tankless install is a different job from swapping a tank heater, and the honest version is that most of the work is not the unit itself:
- Gas supply. A tankless unit fires at a much higher input than a tank heater. The existing gas line is frequently undersized for it, which means new pipe from the meter or a resized run. This is the single most common reason a tankless quote comes in higher than people expect.
- Venting. Tankless units use their own sealed venting, which has to be routed to an approved termination. It is not reusing the old flue.
- Condensate. Condensing units produce acidic condensate that has to be drained to an approved point, often through a neutralizer.
- Location. Where the unit can go is decided by venting, gas and drainage, not by where the old tank happened to sit.
- Isolation valves. We fit service valves so the unit can be descaled later without cutting pipe. Skipping these saves an hour now and costs you every service visit afterwards.
If any of that turns out not to work at your property, we will tell you before you have spent money, not after.
Servicing and descaling
Tankless heaters need more maintenance than tank heaters, not less. Water runs through a compact heat exchanger, and mineral scale builds up on it over time. Scale reduces output, makes the unit work harder, and eventually kills the exchanger — which is the expensive part.
How often it needs doing depends on your water. If we fitted isolation valves, descaling is a routine visit. If the previous installer did not, we can add them while we are there.
When a tankless is the right call — and when it is not
Tankless makes good sense when you genuinely run out of hot water with a tank, when you want the space back, or when the unit is going somewhere a tank cannot easily go.
It makes less sense when the gas supply would need substantial work, when the household's hot water use is modest and well within what a tank handles, or when the decision is being made under pressure because the old heater just failed and you need hot water tonight.
That last one is worth naming. Replacing a failed tank heater is often a same-day job; a tankless conversion is not. If you are cold right now, the practical move is sometimes a tank replacement today, and a tankless conversion planned properly later.
Commercial tankless
We also install and service tankless units in commercial settings — churches, offices and small commercial kitchens where hot water demand is intermittent and a standing tank is wasted energy. That work runs through our commercial plumbing side, and where an inspection is required it is performed under MPL 38224.
Financing
Tankless conversions are one of the jobs where financing genuinely helps, because the gas and venting work is front-loaded. Financing is available through Acorn Finance, built into the estimate we send you. The option appears on your quote, so the first step is asking for one.
Questions we get asked about this
Tankless service in your area
We install and service tankless water heaters in Baytown, Mont Belvieu, Anahuac and across the rest of our service area. If you have no hot water and it is a bad hour, we answer our 24-hour line.
Common questions
Which tankless brands do you install?
We sell and install State, Navien and Noritz. For those three we diagnose the unit ourselves, call for the part, and it is usually available in the Houston area, worst case a day out. That parts pipeline is the main reason we install those brands.
Will you work on a tankless someone else installed?
Yes. We will service any brand. The difference is parts. On a Rinnai in Mont Belvieu the part came from further out and the customer was without hot water for three days instead of one. We will still do the work, we just tell you the timeline honestly up front.
My tankless is under warranty. Who deals with the manufacturer?
We do. If your unit is still under warranty, the manufacturer decides what gets replaced, not us. We get on the video call with their technician, go through the unit with them, get the part approved and shipped, and then fit it. You do not sit on hold trying to describe a fault you cannot see.
Is a tankless water heater worth it?
It depends on your gas supply, your venting, where the unit would sit and how your household actually uses hot water. A tankless conversion is a bigger job than a like-for-like tank replacement. We will price both and explain the difference rather than pushing you either way.
Why did my tankless suddenly stop making hot water?
There are several possibilities and they need diagnosing rather than guessing. On one Mont Belvieu unit the fault turned out to be the thermal fuse. Tankless units log fault codes, which is genuinely useful, but the code narrows the problem down rather than naming the part outright.
Do tankless water heaters need servicing?
Yes, more than tank heaters do. They have a heat exchanger that scales up over time, and how fast depends on your water. Descaling on a sensible interval is the difference between a unit that lasts and one that fails early with an expensive part.
Last updated · written by a licensed master plumber, MPL 38224