tankless water heaters

[hosehose]

Originally Posted by mike99

i could use some advice on thankless water heaters. Pros and Cons. WE have just bought a 2017 Challenger (waiting for it to get hear) and will be taking some long trips in it.

I know this is several years later but I just bought a new rig a month ago in Feb 2021 that also has a tankless water heater (Thor Quantum KW29). I've also seen many new posts in 2020 and 2021 where people are still having problems with these same tankless heaters but it's because they are using them incorrectly. Here's the solution:

1) set the temp switch at the water temp you want, say, for example, 104F

2) Open ONLY THE HOT VALVE and wait for the water heater to kick on and for the temp to stabilize at, in this example, 104F. You're done...don't ever touch the cold water valve. If the water is too hot dial it down at the wall switch but DO NOT OPEN THE COLD VALVE EVER!!!!!

The reason why is that many people make the mistake of treating this tankless system the same as they treat a tank system and they set the tankless temp to say, 130F and then dilute the hot water with cold water when showering thinking this somehow "extends" the ability of the system to provide hot water. It doesn't. It does extend the capability of a tank system but not for a tankless system. The tankless system can provide unlimited water at any temp you want with no cold water dilution being required. In fact, opening the cold water valve on a tankless system only upsets the pressure in the hot water line and this is what leads to surges (and complaints) about fluctuating scalding and then cold water.

So...set the temp you want with no cold water dilution and open only the hot water valve and these tankless systems work great.


Also, be advised that if you stop the flow to lather up and then restart it to rinse off, that you will get a slug of cold water in a tankless system. This is because when the system senses that you stopped the water flow it also stops pouring heat energy into the water. Then when you restart the shower the system takes several seconds before it senses that the flow has returned before it fires up the propane heat to heat the water. During this time, the water is flowing but is not being heated and when it reaches the shower head it's all cold water. Several seconds later the hot water resumes.


So if you stop the flow to lather up, move to one side when you resume the flow and wait until hot water begins to flow again.

[taylorbob1]

Originally Posted by hosehose

I know this is several years later but I just bought a new rig a month ago in Feb 2021 that also has a tankless water heater (Thor Quantum KW29). I've also seen many new posts in 2020 and 2021 where people are still having problems with these same tankless heaters but it's because they are using them incorrectly. Here's the solution:

1) set the temp switch at the water temp you want, say, for example, 104F

2) Open ONLY THE HOT VALVE and wait for the water heater to kick on and for the temp to stabilize at, in this example, 104F. You're done...don't ever touch the cold water valve. If the water is too hot dial it down at the wall switch but DO NOT OPEN THE COLD VALVE EVER!!!!!

The reason why is that many people make the mistake of treating this tankless system the same as they treat a tank system and they set the tankless temp to say, 130F and then dilute the hot water with cold water when showering thinking this somehow "extends" the ability of the system to provide hot water. It doesn't. It does extend the capability of a tank system but not for a tankless system. The tankless system can provide unlimited water at any temp you want with no cold water dilution being required. In fact, opening the cold water valve on a tankless system only upsets the pressure in the hot water line and this is what leads to surges (and complaints) about fluctuating scalding and then cold water.

So...set the temp you want with no cold water dilution and open only the hot water valve and these tankless systems work great.


Also, be advised that if you stop the flow to lather up and then restart it to rinse off, that you will get a slug of cold water in a tankless system. This is because when the system senses that you stopped the water flow it also stops pouring heat energy into the water. Then when you restart the shower the system takes several seconds before it senses that the flow has returned before it fires up the propane heat to heat the water. During this time, the water is flowing but is not being heated and when it reaches the shower head it's all cold water. Several seconds later the hot water resumes.


So if you stop the flow to lather up, move to one side when you resume the flow and wait until hot water begins to flow again.

Very well said
I keep mine set at 109 degrees & it works just like you stated

By the way...welcome to the Forum!

[greg&bev]

Can the tankless water heater in a 2022kw29 run off propane and not electric

[Geterdun]

Originally Posted by greg&bev

Can the tankless water heater in a 2022kw29 run off propane and not electric

They all run off propane as the fuel source. They just need 12 volts for control power.

[greg&bev]

I should know that, thanks

[TheGoodLife]

X2 on your well-said post hosehose. The Girard tankless in our KW29 has been working great thus far.

[galOnTheGo]

We don't have a tankless, would not want one, happy with our tank.
we were at Quartzite RV show this past January, first time for us, liked it very much. there was a manufacturer there selling the tankless, and generators for replacement of OEM. He said he sells the tankless because it seems to be a fad people are jumping on. In his opinion, which I agreed with, it will pass. his generators were very impressive, made to exact bolt-in and wiring configuration making replacement very easy. His generators were very good. If I ever had need of a generator, I would get his. alas, we removed our generator as we never use it. we do use our water heater on accession.

[Jeepman1]

Originally Posted by taylorbob1

Very well said
I keep mine set at 109 degrees & it works just like you stated

By the way...welcome to the Forum!

I also have the KW29. I agree with everything you said. The only downside I have is I boon dock a lot and I seem to fill the gray tank too fast waiting for the hot water to come. I would never buy a tankless and I’m pondering changing to a tank type. Mine works great when I have full hookups but not for boon docking.