Descaling Tankless Water Heater Question

[mig1980]

Good day. I had a Rheem Platinum tankless water heater installed about 16 months ago and want to perform the first descaling. I have everything I need but want to ask if I should disconnect the power (from the electrical cord) on the unit and turn off the gas line before attempting to descale or can the gas remain on?

Here is the unit I have: Rheem Performance Platinum 11 GPM Natural Gas High Efficiency Indoor Recirculating Tankless Water Heater-ECOH200DVRHLN - The Home Depot

 

[JG plumbing]

What do the directions say?

 

[Twowaxhack]

On Rinnai units I turn the power off. I leave the gas on.

 

[mig1980]

What do the directions say?

The manual does not instruct on this process. It simply states to contact a licensed professional.

 

[JG plumbing]

If I were you I'd follow that advise.

You don't want it to kick on and lock you out for tripping some kind of fault. Flip the breaker or disconnect to turn it off. The gas won't turn on unless it's on.

 

[mig1980]

What do the directions say?

The manual does not instruct on this process. It simply states to contact a licensed

If I were you I'd follow that advise.

You don't want it to kick on and lock you out for tripping some kind of fault. Flip the breaker or disconnect to turn it off. The gas won't turn on unless it's on.

So disconnecting the power to the heater should be enough? I shouldn't have to also close the valve for the gas line to the heater?

 

[JG plumbing]

You could close the valve for extra saftey, but you don't have to. Don't take the gas line apart though.

 

[mig1980]

You could close the valve for extra saftey, but you don't have to. Don't take the gas line apart though.

Perfect! Thank you

 

[Mitchell-DIY-Guy]

TheIt simply states to contact a licensed professional.

Right. And now the stark reality of owning a tankless heater comes to light. Descaling is something that needs to be done on a regular basis more or less depending on the quality of your water. They don’t provide you instructions because the manufacturer believes you don’t have the capability of doing that as a homeowner. So you really need to call not just a licensed professional but somebody who is a Rinnai dealer— not for any other reason then the manufacturer won’t believe that anyone else except the people that they authorized to sell and service the unit have the capability of doing so. The pros can weigh in here but you’re probably looking at the cost of a service call plus may be an hour of labor. Probably at least a couple of hundred dollars.
If you don’t call a Rinnai dealer, and you don’t schedule this according to the maintenance program, (annually?) you will lose the warranty if you still have one.
If the unit is out of warranty of course you can call any competent pro to do this. Hopefully whoever installed it added the proper valves on the input and the output so you can easily disconnect the system from your house plumbing and connect the descaling pump and hoses.
There are a number of good videos on YouTube that show the material they use for descaling, the process, and the equipment needed. It’s not terrifically complicated it just takes some time.

 

[Hamberg]

Good day. I had a Rheem Platinum tankless water heater installed about 16 months ago and want to perform the first descaling. I have everything I need but want to ask if I should disconnect the power (from the electrical cord) on the unit and turn off the gas line before attempting to descale or can the gas remain on?

Here is the unit I have: Rheem Performance Platinum 11 GPM Natural Gas High Efficiency Indoor Recirculating Tankless Water Heater-ECOH200DVRHLN - The Home Depot

(I have the same unit) Just did mine last week - yes, shut off gas at unit and unplug. Assuming you had the service ports installed, a submersible pump, two hoses, a bucket and 1.5 gallons of vinegar? EASY job after that - should let it run for 1-2-hours.

Also, if you are handy, install one of these: https://amazon.com/3M Aqua-Pure Whole House Scale Inhibition Inline Water System AP430SS. Need to replace the cartridge every 3-6 month depending on water hardness but it keeps the scaling way down!

(edit: if you need further instructions, let me know)