Rennai tankless hot water

[1750]

Does anyone know if I have to do anything special with this unit if I cut the power to my well pump?

I would like to turn off the water to our cottage (it's still heated) and drain the pipes to reduce risk of water damage if the pipes happen to freeze.

Thanks in advance for your thoughts on this!

 

[Frozen Canuck]

If the installer was on the ball, it should have a pair of webstone valves on the bottom allowing you to run a cleaning solution through it. These same valves can be used to drain the heater, don't forget to shut off the power & the gas as well. Bad idea if it's a prolonged absence to just walk away as any sediments in the water will settle out & start coating the HX in the unit. Unit should drain through the webstone valves leaving the HX empty & you won't have to worry about freeze up.

 

[1750]

Whoa, thanks for the great answer, FC!

I saw those valves on the bottom, so I think my installer was on the ball.

If I shut off the power and gas to drain it, when I turn it back on, does it fire up on its own, or do I have do something magical to get it back on line? Also, I think the chances of something freezing up are very low (we are only gone a week or two at a time), so I wouldn't want to do anything that would potentially harm the system just to reduce the small chance.

If I turn off the power to the well-pump, is there any harm in just leaving the Rinnai unit as is?

Thanks again. I really appreciate your response.

 

[Frozen Canuck]

If I shut off the power and gas to drain it, when I turn it back on, does it fire up on its own, or do I have do something magical to get it back on line?

Nope they are pretty much auto restart with the exception of the water temp which you can set at the control panel on the unit. Close the valves that you opened to drain unit, turn on the water, turn on the gas, power up unit & set limits on the unit panel. You kept your manuals right? Hope so as the restart procedure for your model is in those pages.

If I turn off the power to the well-pump, is there any harm in just leaving the Rinnai unit as is?

Nope, very reliable units, however depending on the model there may be a pressure sensing switch which should in the event of no water pressure shut off the unit & send it into alarm. Waiting for you to correct the situation that caused the alarm. Again you kept your manuals right?

BTW I love mine, currently 6 of us in the house & my unit keeps up to every tap running & all the appliances.

 

[1750]

I always keep my manuals! I was reading this one today, however, and couldn't make much out of the diagrams.

& set limits on the unit panel.

By this you mean just dial in the temp for the hot water?

I'm really impressed with the unit so far. I am trying to convince my daughters that perpetual hot water should not equal never-ending showers. I think they are with me on this... at least in spirit.

Thanks again, FC!

 

[Frozen Canuck]

By this you mean just dial in the temp for the hot water?

Correct, mine has a screen that allows input by the operator however there are many models.

I am trying to convince my daughters that perpetual hot water should not equal never-ending showers. I think they are with me on this... at least in spirit.

Ha! Good luck with that one! Get used to them telling you what they think you want to hear & then doing what they want anyhow. It gets worse….wait till they discover boys, then you will beg them to stay in the shower all day & night.

 

[1750]

Thanks again, FC. That's really helpful to know. I didn't really know much about it.

Have you ever done the clean out in vinegar that's in the manual? Do you need to have an external pump to circulate the solution? (it looks like you do from the diagram in the manual, but doesn't mention it in the text.)

Thanks again!

 

[Frozen Canuck]

You are welcome.

Have you ever done the clean out in vinegar that's in the manual?

Annually, well water on the hard side here. Water softener on line however I like to make sure so I run the solution.

Do you need to have an external pump to circulate the solution? (it looks like you do from the diagram in the manual, but doesn't mention it in the text.)

I use an old aquarium pump to circulate the solution, solution & pump in a pail on the floor, hose to each webstone valve from pail. Pick a day when everyone is not using hot water, hook it up, turn the valves, turn it on in the morning. Shut it off & disconnect & turn valves back when you get home in the evening. Don't forget to shut the unit off or put it in maintenance mode (depends on the model), then reverse that when done cleaning.

Once you get the hang of it you will need 5-15 min/yr. Pretty simple/easy maintenance.

P.S. Consult your manual for a maximum concentration of vinegar (a mild acid) as they do have different HX's by model.

I think 10% solution is the max anyone would ever need but it only takes a minute to check.

 

[1750]

I have the aquarium pump and the bucket already in the basement!

My manual says "4 gallons of food-grade white vinegar." (That's just a paraphrasing of the quote... I don't have the manual in front of me.) The manual also says there's a message that pops up if the unit needs to be clean, but it sounds like I should just do it yearly -- we don't have a softener.

Thanks again.