Question on proper settings for recirculator timer

[Don Awalt]

Hi, we have a Navien CR-240A tankless water heater, we have lived in this house for 3 years and it was here when we moved in. It works great, and we get the maintenance every year to descale it, etc.

I have questions on the proper settings for our recirculator timer. I know how to do it, but I have it set to be on the whole 24 hours so we always have hot water. I suspect this is wasteful. So my questions are:

1 - what is the difference in how fast hot water comes out in a time prior with/without the timer on?
2 - how long does it take to heat the water in the small tank if I want it ready for say, family morning showers? In other words, does it need a preset time of 30-60 minutes say, to be ready for 5 AM showers.
3 - should I just have the timer on during times of heavy hot water use (showers), or other times (I guess this answer is based on the answer to #1)

I guess I am just looking for some guidance on how to decide which time periods should have the timer on vs. off.

Thank you!

 

[John Gayewski]

Im not as familiar with the A models. The A2 will learn your patterns and act accordingly. You can also (I think) add a wifi controller to the A and get better control features.

Do you have a dedicated recirc line? If you do it will take longer to heat the piping and water and tank up. If your just an internal recirc home it shouldn't need more than a few minutes to heat up.

 

[Sponsor]

 

[Jeff H Young]

Trial and error If you shower at 5 am like a clock Id set it 10 minutes early. most have a aquastat as well so pump dosent run at all times . then as john says more sophisticated systems are out there youll have to study up or leave it as is

 

[Don Awalt]

Thank you. What is the difference between the recirc running - I know we get "instant" hot water in about 2-3 seconds it seems, what's it like with no recirc running? Does it take say 20-30 seconds to get hot? Or is it longer - is the "instant hot water heater" only instant if the recirc is running?

Maybe this will help me - how do others here have their timer set throughout the day if the have instant hot water heater with a recirculator timer - for example, just 6 AM - 8AM and 4 PM - 8 PM, or many more time increments throughout the day?

Thanks for the advice and sorry for all the questions!

 

[Bannerman]

Does it take say 20-30 seconds to get hot?

That's going to depend on the distance between the WH and the fixture(s) you are using.

An option to allow recirculation anytime before hot water will be needed, will be to activate recirculation for a preset time period. While preparing to shower, wash dishes, laundry etc, recirculation could be activated for a 10-minute period, thereby resulting in the hot water supply pipes to be filled with hot water in advance of use.

Navien offers a HotButton add-on accessory for its tankless systems.

Navien HotButton

 

[Jeff H Young]

ok imagine you havent used any hot water in your home for hours and you open a faucet far aw2ay from the water heater you well the pipes and water in them are cold and it takes time for the hot water to arrive a circ system will circulate the water so that hot water is closer by and it wont take as long for hot water. I dont have a circ system maybe try reading up on them a bit itll be a little easier to explain . you might want to upgrade some things to not over work the system