Tankless Hot Water while boondocking

[Wolfstar]

We are living in our 2019 Thor Quantum 29KW with a tankless water heater. Turning on the hot water (without engaging water pump) delivers cold, then a brief hot water moment, then cold again. HELP...tired of heating up water in the microwave (we do have electrical hook up - 20 amp - 10 less then our 30 amp load max).

[Trkyte@msn.com]

Sounds like a low pressure flow.
Are you hooked up to city water?

[Wolfstar]

Nope but I have a switch for the water pump and I have not switched that on.

[Bob Denman]

Try it with the water pump engaged.

[Coveman2]

I am not sure how you are getting any water if you are not hooked up to city water and your pump is not on. Make sure your fresh water tank is full and then switch on the pump and let the pump run , turn on a tap (cold then hot) and make sure all the air is out of the line and see if the water stays hot but run the hot only. Shut off the water and if the pump stops its primed and you should be good to go, the tankless water heaters are sometimes hard to get used to how they work
Coveman2
2018 Thor Compass 23 TB

[V1VR]

My limited experience with my tankless WH is that when the only pressure supply is the house water pump performance suffers and hot water “dribble” is sop.
The system needs pressure as close to 50psi as one can supply and at that point using only the hot water supply unmixed (no cold) and system is set at the desired temperature on the system control panel will performance come close to satisfactory. JMHO

[paulwadley]

The tankless hot water systems needs between 50-55 psi water pressure to work properly. When I hook up to city water, I use an adjustable water pressure valve set set to 55 psi and have the temp set to 106. I then turn on the hot water only. Works great at that point.

[Judge]

Originally Posted by V1VR

My limited experience with my tankless WH is that when the only pressure supply is the house water pump performance suffers and hot water “dribble” is sop.
The system needs pressure as close to 50psi as one can supply and at that point using only the hot water supply unmixed (no cold) and system is set at the desired temperature on the system control panel will performance come close to satisfactory. JMHO

I don’t have that problem with my coach when I’m using the fresh water tank.

You may want to check your water pump, strainer and filter. The system should generate enough pressure for continuous hot water if you only use the hot water, set the temp you want and don’t mix cold.

I would also pull the strainers in every faucet and shower head. I have found construction debris in them on new coaches restricting water flow.

[Bob Denman]

Originally Posted by Wolfstar

Nope but I have a switch for the water pump and I have not switched that on.

Has anybody else noticed this statement??

[Judge]

Originally Posted by Bob Denman

Has anybody else noticed this statement??

Yikes.... good catch Bob!!!!

[Bob Denman]

I don't know how I saw it and nobody else did: I'm the blindest guy in here...

Suffice it to say: the water pump needs to be running; if you expect to have water pressure, and a good flow of the wet stuff...

https://www.thorforums.com/forums/at...1&d=1589209280

[Travelin' Texans]

Originally Posted by paulwadley

The tankless hot water systems needs between 50-55 psi water pressure to work properly. When I hook up to city water, I use an adjustable water pressure valve set set to 55 psi and have the temp set to 106. I then turn on the hot water only. Works great at that point.

The adjustable regulator will not increase low pressures they only reduce higher pressures to the set pressure. If the spigot only has 45psi you'll only have 45psi in the RV regardless what the regulator is set at.
Id think that if the RV is equipped with a water heater that needs 50-55 psi they would put in a pump that puts out that much, but it is a RV so ANYTHING is possible.
Also tankless water heaters doesn't mean instant hot water. RVs typically have long runs of small diameter uninsulated piping so it takes a bit for the hot water to reach a faucet.

[EA37TS]

Seneca owners over on the Jayco forum have modified their rigs to install recirculation systems so the hot water in the lines is always hot and they are not wasting grey tank capacity trying to warm water for dishes or showers. Their systems periodically recirculates through the water water heater and dumping the cold/cooler water back into the fresh water tank.

[Bob Denman]

That's what my Truma system does...

[Wolfstar]

Thanks to everyone who responded. Got her done and now enjoying hot water...helps to turn the system on at the bedroom control switch. Hooked up to the farm faucet for ongoing incoming water...with filter and pressure gauge.

Suffice it to say, you all are great resources that help walk us through the problem to solution. As a relatively new RVer (been on a total of 4 trips) still working out the kinks. You remain my saviors.

Wolfstar

[Bob Denman]

Glad to see that you got it sorted out.

[Coveman2]

You are welcome and if you are not sure just ask , there are a lot of great people with lot of RV experience, to tell you where to go !!!!!!!!!!!!!!!!!
Just Kidding
Coveman2

[Wolfstar]

From the many posts I read with every Forum email, I believe you to be quite the scoundrel I very much enjoy scoundrels !

[GVP-The Boxcar Children]

Congrats on the resolution! Our Aria's hot water ONLY works with the pump on regardless of city or tank water. Once we figured that out, along with how best to regulate the temp, we've had hot water whenever needed.
GVP

[Grizz]

Originally Posted by GVP-The Boxcar Children

Congrats on the resolution! Our Aria's hot water ONLY works with the pump on regardless of city or tank water. Once we figured that out, along with how best to regulate the temp, we've had hot water whenever needed.
GVP

Funny how quirky these things can be! On my Aria the hot water works fine on city water with no pump or tank water with pump. These things can make you scratch your head sometimes.