To improve water pressure with this setup, I’ve tried changing the angle valve to one with less restriction (wider outlet visually). I think it improved but still not satisfying.

Will changing from flexible piping to rigid piping straight into the heater improve pressure or more recommended to install heater with built in pump?

Do newer heaters consume less electricity than old units like AC or no?

Change to rigid will improve due to bigger diameter , any old heater if compare to new will save electricity due to deposit build up inside heating element , old will need longer time more power to heat the water

if the original water flow is already very slow, i think it will barely make a noticeable difference.


Instant water heaters usually require water flow of at minimum 2 litres / minute to turn on, regardless of whether they have built-in pumps or not. So if your existing instant water heater is currently not able to operate due to low water flow, getting a new instant water heater with a built-in pump will not solve your problem too, since the water heater is still not able to be turned on.

But if assuming your bathroom has at minimum consistent 2 litres / minute water flow, yes water heater with built-in pumps will slightly increase your water flow. A water heater with built-in AC Pump is stronger than built-in DC Pump, but AC use more electric, is noisier, and has a shorter lifespan. N instant water heater's built-in pumps are small too, so don't expect hotel-like water pressure, just a minor increase in water flow.

Best option is to get a booster pump like Grundfos (example here: Lazada/Shopee) that is installed at your main water supply, to boost water pressure throughout your house.


Agree with @keanutan's explanation above. The older the water heater, the higher potential it has more dirt / scale buildup on the heating element surface, hence minorly reducing heating efficiency. This is especially true since your angle valve doesn't look like it has a mesh filter to reduce larger dirt / particles from entering into the water heater. Your water heater definitely looks more than a decade old, good time to change if u want an upgrade.

That Joven heater is at least 20 years old. I can't imagine the amount of scales coating the internal surface of the heating coils, which reduces water flow and heating efficiency.
I would definitely consider changing it, and add a 10mA RCCB while at it.

I have been told it is ~25 years old. However was only used a handful of times before 2021.

Since your instant water heater is older than millennials, u might want to double check and make sure your bathroom electrical infrastructure is up to standards when reinstalling a new instant water heater.




1. Use the correct cable size | most common instant water heaters in the market have power ratings between 3.6kW to 4.2kW, which means u should be using 4mm² cables to connect to these water heaters, according to the Suruhanjaya Tenaga guideline table shared above. Under-spec cables (especially those below 2.5mm²) might melt / catch fire. A good brand to go for is Fajar Cable. U can get the 4mm² cables here - Lazada / Shopee




2. DO NOT use plug + socket connection in the bathroom | They are not water proof & increase your risk of getting electrocution, and the 3-pin plug fuse might burn, especially for higher power water heaters, eg. brands like Deka & Rubine now have higher powered 4.5kW instant water heaters, which increase the chances of 3-pin plugs to burn if used together. U can overcome these electrocution and fire risk by either connecting the cable directly to the water heater without going thru and plug + socket connection, or replacing the 3-pin socket with a water heater connector using this same junction box. U can get the water heater connector here - Lazada / Shopee




3. Make sure there is a 10mA RCCB / ELCB for your water heater's electrical connection | As stated in the Suruhanjaya Tenaga guideline shown above, and as shared by @mushigen. Its purpose is to protect u from dangerous voltage in the event of short circuit / electrical overload. Here are some RCCB brands u can get:

- Schneider | Lazada / Shopee
- Hager | Lazada / Shopee
- ABB | Shopee