My cw series is a plumbed-in unit. Water flows continuously from the spray head. I think that either (1) the water level sensor is bad (2) the shut off valve is stuck open. Ideas? Can the water level sensor be cleaned? Is it in a place that is accessible?

https://spares.hansgrohe.com/etk/INT/product/04076000/8809627168611.seam?fsid=0x000077210000704100006F91&lang=en_GB&wcms=INT
https://assets.hansgrohe.com/mam/celum/celum_assets/16__hruh0765_pdf.pdf?5&_ga=2.43849249.583112013.1552939079-215678084.1552939079

The faucet is rated at 6.7L/minute (<2 gal/m) and I would expect that's a design of the cartridge. You could measure flow with spray head attached, then remove head (see link) and measure again to see how much the head reduces rate of flow. You could try removing the check valve(s) but not sure if that will work as it may leak.


product features · consists of: single lever kitchen mixer · swivel range 150° · with telescopic function (330 - 500 mm) · normal and spray jet · lockable shower spray, spray returns through pressing spray diverter · quick connect shower hose · flow rate 6.7 l/min · ceramic cartridge · connection type: G ? compression · integrated non-return valve · suitable for continuous flow water heaters

check that the fill valve was installed correctly
adjust the float level so that when full the cistern water level is around 1/2" below the over flow pipe end
what you have now is that the inlet water is not being shut off correctly and the water is still coming in and flowing out of the overflow

Most likely it is scale on the lvl sensor, what model is the unit? Also, do not use viniger on plumbed units, you will almost never get good coffee out of it unless you pop the tank lid and drain the tank.

It sounds to me like you have a defective thermal switch that is shutting power off as if motor is overheating.Unless you are exceding the head or flow ratings on the pump I would recommend you return it for replacement.Thank you.

Hi and welcome to FixYa, I am Kelly.

What is happening is that your cold water flow is greater in volume (gals per min) than your hot water. So when you open the cold water it is mixing with the hot water inside the faucett or shower plumbing and actually reverse flowing back into the hot water heater plumbing. The reverse flow slows the water flow sensing turbine inside the heater and it is thinking that there is not any water flow. (There isn't actually due to the equalization of water pressure when you open the cold water faucett) Since this is a safety feature of the tankless heater to keep it from overheating, it shuts off.
Somewhere in the hot water plumbing there is a major restriction. It may very well be the internal plumbing of the tankless hot water heater or the flow detector design.

There are 2 ways to correct this. The easy way would be to restrict the available cold water flow. You can do this by installing another shut off valve inline with the cold water plumbing and just not open the valve all the way. You would have to adjust the setting so that the hot and cold water can be on at the same time and the hot water heater stays on. The hard way is to locate the hot water flow restriction and eliminate it.
It is possible.... if you have a flow restrictor in a shower head or a screen in a faucett areator that they are partially clogged. Clean any flow restrictors and screens then see how the hot water heater performs before you start modifying plumbing.

Thanks for choosing FixYa,
Kelly

your fill switch is either bad or "gllitched" and the timer cannot move until this switch senses the right amount of water for the load unless its an electronically sensed water/load capacity filled machine,when it starts,the water fills the unit and the pressure switch shuts the water fill off when at selected water level and powers the timer to continue the wash cycle,it works off a "bellows" on air pressure to change a switch by air pressure to operate the machine when full of water

Sounds like the solenoid is the problem.

A few things you should check:

1. Cross Connections - this occurs when cold water leaks into the hot water system through a fixture. In order to check for a cross connection: 1) turn off the cold water to the tankless 2) open up hot water fixtures in the home. The water should shut off at all hot water fixtures; if there is a continuous flow of cold water, then you have a cross connection. The most common place to find a cross connection is on old shower cartridges.

2. Ask the customer to check to see if the burner indicator is continuously lit during operation.

3. When the water goes cold at one fixture, try another near by fixture to confirm it is also cold there. If its hot at one fixture but not the other, then you have some issue with you plumbing. Tankless heaters can't pick and choose which fixtures to deliver hot water to.

4. Tankless water heaters all have a minimum flow rate that must be maintained in order to continually fire (.5 gpm for Noritz). Ensure their hot water fixtures flow at least this amount, or that the customer isn't mixing too little hot water at their fixture.

5. If they see the cold spurt during initial firing, they may be experiencing a cold water sandwich. When the heater moves from a standing state to a firing state it takes a short period to ignite and heat water. During this time it will be passing cold water through the system. Usually this cold water mixes with hot water in the line as it travels through the plumbing system, but if their fixture is very close to the heater, there won't be enough time to mix.

6. If debris has gotten into the flow sensor, this can prevent the unit from registering flow and cause intermittent firing.

You mean the main plumbing supply to the house? NO WAY! Something is terribly wrong somewhere but not in your unit.

the tank is not full. the sensor at the top is being bridged and it thinks it's full. pop it out and clean it and delime the tank.