Tankless water heater?

[DorisStanKing]

Just bought a slightly used MH with a tankless water. Hubby went to take a shower & one minute he's got cold water & the next he's getting hot water. All this happens when the knob is in any position. There's no consistency. It happens at all faucets as well.

Do anyone know what the issue might be. Thanks in advance!

[captnrick3]

Originally Posted by DorisStanKing

Just bought a slightly used MH with a tankless water. Hubby went to take a shower & one minute he's got cold water & the next he's getting hot water. All this happens when the knob is in any position. There's no consistency. It happens at all faucets as well.

Do anyone know what the issue might be. Thanks in advance!

There is definitely a learning curve using a tankless water heater, not at all the same as a tank type. Once you get it nailed down and assuming there are no problems they are fine. Rule of thumb, higher the flow, the cooler the water, lower the flow, the hotter the water. There should be no re-stricter in the shower head. Most of the time just use the hot water knob only. If water gets too hot the unit will shut down, that's when you get the cold water. Very consistent flow rate and pressure are important, must use a high quality regulator if on city water. Hope that helps.

[CSMRetired]

This has been our practice
Open the hot water valve about half way....kind of slowly
When the water gets hot....blend the cold water in
Pressure has a lot to do with it as well.....they seem to work much better at 50 psi or a little better, anything below 48 psi and they don't perform all that well
So try our method and see how it works....it is a learning curve, don't get discouraged

[Crockett]

how about when your dry camping? can you set the valves and then use to shut off on the wand?

[captnrick3]

Originally Posted by Crockett

how about when your dry camping? can you set the valves and then use to shut off on the wand?

In our experience dry camping takes a bit more learning. We do not use the wand valve because when that valve is off it leaks quite a bit. When it is leaking, there is not enough flow to turn on the heater so cold water fills the line, then you get a blast of cold water. I use only the hot water valve and turn it all the way on or off for the best flow. We dry camp a lot and this has served well. I'm sure every rig has little nuances. I am finding our tankless heater to be very fuel efficient, better than what I expected.

[Crockett]

im told they mfg with a little leak so folks know the faucet is on. seems like its time for true shutoff. the fitting is 1/2" pipe thread. maybe just fab a pvc shutoff...less than $10 total cost but fairly hideous

[DorisStanKing]

Thanks for the replies. We've been working with it & after calling the MFG I think we're getting a handle on it.

[mvpmich]

Originally Posted by Crockett

how about when your dry camping? can you set the valves and then use to shut off on the wand?

They are not designed to work "military style" as they need constant water and consistent pressure. The fallacy of the "fuel" efficiency is that you use more water thus reducing the available capacity of the holding tanks. We purchased a DP for added tank capacities and found that we didn't gain anything trying to make the energy efficient, on-demand water heater work properly. As a result, we had it removed and installed a traditional 10 gallon gas/electric unit. All is well now.

As a side note, we could not in good conscious allow our 9 year-old grandson use the shower by himself with the on demand unit due to the constantly changing temps. He is also a little modest and didn't want us in the bathroom with him. The traditional unit works better for him as well.