Question about Rinnai 351-R50LSiN - Water Heaters - Tankless Internal Residential And Commercial 5.0 GPM LS Water Heater - Natural Gas

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Unit not coming on. There is water, gas, and electric. I can adjust digital read out for water temp, but unit is non responsive.

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Have you reset boiler and gone through start up procedures.if so it sounds like an ignition problem? you need to explain what happened before you adjusted the water temp and why?

Posted on Dec 12, 2012

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Pop-off operated suddenly on elec ops. Went to LP ops & same problem when water heats. Help!

What you are referring to as the "pop off" is the OVER-TEMP SAFETY DEVICE, which is designed to prevent the unit from overheating (and potentially exploding). It is infrequent that these fail but they sometimes fail. As a temporary measure, lower the temperature on the thermostat to a point below where the over-temp safety is triggered.

May 11, 2015 | Atwood GE9-EXT Gas and Electric XT 6...

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How to adjust the temperature

Great question.
On the back of the unit you should see two small adjustment screws, You will need a flathead screwdriver (generally) and you can turn these dials to increase or decrease the water temp.
This unit may have a plastic panel on the rear that has to be removed first before being able to access these regulators.

Sep 30, 2013 | Ragalta Thermo Electric Hot/Cold Disp -...

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Turned down temp on Water Heater a little, and now we are not getting any hot water. Not even Warm. Whats wrong?

For electric tank: Push in the reset button located on upper thermostat.

For gas tank, then more specific information might be needed for example if unit has power vent, when was the air intake cleaned, is the pilot lit, what brand and model number etc etc..

For tankless, or solar, or hybrid electric, gas boiler, or indirect, or RV heater, etc then please include brand, and model that appears on label on side of unit.

Sep 05, 2012 | Rheem 50 GAL ELEC TALL Water Heater 6YR SC...

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I have a Bosch Model GWH 1600 H tankless water heater. I have had issues with it since I installed it 2 years ago or should say had it installed.Yesterday I could not get it to ignite or light manually. I...

Igniter can be ordered, but that may or may not be the issue.
Your tankless unit -and- plumbing system need total check-up by trained service technician.
Open following links for Bosch troubleshooting resources including contact Bosch, manuals, error codes, water flow etc.
Check electrical outlet with circuit analyzer to make sure polarity is correct.
Typically, gas water heaters, and especially tankless water heaters require yearly maintenance by service technician who can check the gas pressure and supply, venting, electrical connections, PC board, sensors, burner orifices and igniter parts are clean and positioned correctly, vent is draining correctly and not dripping back into combustion chamber, correct temperature is achievable, incoming water temperature is not too cold for temp setting, proper incoming air supply, adequate air supply, no chemicals stored in air supply pathway, filters are clean, plumbing check valves, mixing valves, pressure valves etc are permitting one-way flow of hot water, water is softened to less than 11 grains hardness, water is filtered and not dirty, aerators and other faucet parts are clean and support water flow necessary to activate burner.

Jul 15, 2011 | Bosch 1600H-NG Natural Gas AquaStar...

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I have a instantaneous water system 10H Hydropower ...did not get a manual when installed....I need to have hotter water as it's winter and the water is like warm...not sure what to adjust...opened...

take the cover off the 10 h unit light up the burner by turning on the tap turn the water flow tap on the front of unit (white knob) clock wise slowly feel hot water pipe coming out off unit when temp increases put cover back on check temp at sink if too hot turn knob anti clock wise

May 23, 2011 | Bosch Water Heaters

1 Answer

Im looking for the best option to get a Rinnai unit that would supply water at 30c or just below. i was going to buy the REU 55RT but looking at the manual i dont know how low the temp can get

Most tankless are preset to 120 degrees F.
30 degrees C is 86 degrees F.

If you want adjustable product, then tankless is not best choice.
Tankless are high tech gadgets with multiple interrelated parts controlled by sensors feeding information to control board. Everything internal and external has to be working correctly for tankless to work at all.
Most tankless brands do not suggest self-install, or self-adjustment, or any adjustment for reason given above.
You would be better off buying typical tank-type gas or electric and then thermostat adjustment is simple.

Add a comment for more free help.
Also take advantage of fixya expert assistance live.
For a price, expert works with you while you work on water heater or any do-it-yourself project.
Fixya is always less expensive than a service call.

Mar 23, 2011 | Rinnai Digital Remote Water Heater Control...

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Tankless water heater water will not come out hot enough

1) Read your manual

2) De-lime unit on yearly basis:
Search google and Utube for 'de-lime tankless'
They make special fittings that permanently attach to water ports so you can delime each year.
Research shows that reqular de-liming will not restore tankless efficiency.

3) Typical manual shows temp information on page 22-23. Search pdf for 'temp'

4) Read maintenance steps shown in manual
The word maintenance appears throughout the manual

5) Search fixya questions on tankless to glean information about your unit:
Older answers have more responses, and each seems varied as techniques succeed for one person but not another.
The quantity of unanswered questions and vague answers reveals why Rheem suggests qualified technician be added to your rolodex-wallet

6) Other useful links for tankless owners:

Add a comment for more free help.
Also take advantage of fixya expert assistance live.
For a price, expert works with you while you work on water heater or any do-it-yourself project.
Fixya is always less expensive than a service call.

Mar 04, 2011 | Rheem Tankless Hot Water Heater...

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How do you check the temp coming out of the unit on this controller

you need a thermometer. like this one...

hold it under the hot water. this is what I use, they work great and pretty accurate.

Sep 06, 2010 | Rinnai Digital Remote Water Heater Control...

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Hot water heater states lockout

lucky for you I jst did one of these the other day same problem,, check the wires on the ignitor, some of them are thinly coated and causes them to short out, wrap electrci tape around them individuly turn off the unit , wait 30 sec, turn it back on at it;s lowest tem hold both temp buttons at the same time till lights come on the after it lights set the temp

Jun 06, 2009 | RTO W4 A.O Smith Gas Hot Water Heater...

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What is the inlet temp of the water? If it is cold, your output will suffer. What is the flow into the unit? If it's too fast it doesn't have the proper time to heat the water to full temp. Is this gas or electric? Electric units have more issues than gas. If its electric, one of the elements could be bad. Check your breakers and make sure one of them hasn't tripped (electric). If it is gas, check that you have the correct temp set.

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