Hi all,

Recently I purchased a Panasonic DH-3RP1 Water Heater. However, it is found that the DC pump continue working even though i turn off the water to the water heater.

As per the spec, I assume it should be turn off totally when there is not water supply to the water heater.




I had a chat with the seller, the seller tried to obtain information from other (probably his supplier). Seem like the supplier mentioned heater and pump work differently.




Do anyone has this same model and can give me some insight whether am I receiving a faulty unit. Or the supplier is just trying to play his word game.

Thank you.

Why didn't you contact Pana CS ?

Sellers or sales people are not a technical person. They will know some common but not specific problems.

Thanks.

Able to search online.
https://www.youtube.com/watch?v=hVB6VDGUTn0

It seems like it is kind of design flaw.

quoted from some of the comment:


@manvinderbhullar7821
1 year ago
I recently bought the same model because it said 'Flow Switch' on the box. A flow switch detects the flow of water and turns on the heater when water is flowing and turns it off to prevent the heater when the water stops flowing. I was under the impression that this would also control the pump (just like the other brands I have used and surely Panasonic can't be worse) but I was wrong.

Now if you leave a water pump running without water in it you will probably damage the pump's seals etc. The motor will not be affected much unless the pump seizes(jams) and then the motor will be locked and the current through it will rise, possibly damaging the motor too.

Sad to say this is a poor design. For example when you have wet your body enough to start soaping your body or shampooing your hair, you turn the water off. But the pump keeps running and then you have to turn the power knob off to preserve the life of the pump. After soaping, you turn the water on and then turn the power knob to the 'on' position. The knob is round and smooth and now you get soap all over the knob as you grip it hard to turn it with slippery fingers.

If the designers had not intended to control the pump via the flow switch they could have at minimum provided a push on, push off switch or put some curved indentations into the knob. But still, I find it hard to understand why they can't turn the pump off when the water stops flowing. Of course it will increase the cost by a few bucks but it's better than getting bad reviews.

Conclusions:
1)Don't bother with this model.
2) Don't assume anything in future even with big name brands

Yes I've this model. The pump doesn't auto off. The only good thing about it is the pump is quiet.

thanks for confirming this.
yes, the pump is quiet, but not as powerful as expected.

I have both old and the latest push on off model. So far all good. The oldest being 13 years without any issues.

This model pump must manually OFF using the bottom round knob, the one just below the temperature knob. Then only can off water and mains

Otherwise pump will still running and may rosak overtime

As of why, this is BY DESIGN, cut cost

This post has been edited by MyProLife: Oct 18 2023, 07:36 AM

Is there anyone feel that this water heater is not hot enough....? I need turn the water to very little just to feel enough heat...

Output water temperature for an instant water heater is affected by:

1. Inlet water temperature - The lower the original water source's temperature going into the instant water heater, the lower the output water temperature.

2. Power rating - The higher the instant water heater's power rating, the hotter the output water temperature. Panasonic DH-3RP1 only has a 3.6kW power rating, while other brands nowadays commonly produce 3.8kW to 4.2kW. If u want an equivalent model (low cost with DC Pump) with a higher power rating, u can try CENTON EcoAtlantis 4.2kW with DC Silent Pump, link here ( Shopee / Lazada )

3. Water flow - The higher the water flow, the lower the output water temperature. Panasonic shower handsets has smaller spray nozzles compared to other brands, hence water flow is slower which results in hotter output water temperature. But in return the shower handset spray can be very needle-like and painful if water pressure is high, and some people will find small amount of water flow unsatisfactory during showers.


But if u want to maximize the output water temperature, u can get the CENTON EcoAtlantis 4.2kW shared above, but remain using the Panasonic shower handset.




This post has been edited by Selene Yeo: Aug 3 2024, 12:00 AM

hmm...maybe can consider upgrade once my unit spoil...btw it just 3 years old..i have change the shower head and hose into third party and hose using Joven.

I use a Pana DH-3KP1, since 2012 till now, never has a problem. It has a puch button to stop water and heater when I apply shampoo and soap. Yeah agree this is not the best design, it should auto stop the heater when water is low or stopped.