Hi, I plan to purchase a water heater without pump and then install an additional shower head to it.

The default shower head i will still use it but at the same time i wish to have a rain shower head also. Since the default did not come with the rain shower head, so i will purchase 1 from Mr. DIY and install it to the water heater.

May i know is this doable? Is there any problem if i do it like this?

How about your house water pressure?

Better at least to buy water heater with pump, otherwise install pump after water tank.
Even I installed water tank with pump in 1st floor bathroom for my landed unit, the rain shower still not optimized as expectation.

This post has been edited by easywin3: Aug 19 2018, 12:39 PM

Why don’t buy the water heater that comes with the rain shower head and secondary normal spray shower head. No need to DIY and confirm can be used. If your water pressure is not strong better get with pump.

Your water pump undersized causing the rain shower to not have enough flow.

Even you have no problem with water pressure, you might face the water cannot reach the temperature.

Rain shower require high water flow which your heater might not have enough power to heat up the water.

If you want to buy, check carefully the heater watt power.

unknown at the moment

no pump is cheaper.....

how does this affect how fast the water can be heated up?

higher watt faster heat?

This post has been edited by quireyuyue: Aug 20 2018, 01:14 PM

1) Water flow pass a 1meter hot tube (100°C) from beginning point to the end of the tube point at 1sec speed will pickup how many heat from the tube.

Compare flow at 2sec speed .

2) Water flow pass a 1meter hot tube (200°C) from beginning point to the end of the tube point at 1sec speed will pickup how many heat from the tube.

Compare to hot tube at 100°C.

I guess you understand this.

I believe there is no problem for heating the water

But low water pressure will make ur rain shower head suffer

If you want to enjoy hotel type rain showers, get storage heater with pump or solar. Instant water heater won't be able to do that (most Malaysia model) you need high power version which I don't see before.

High water pressure required high power water heating elements.

My sister stay in condo, water pressure is good, she install instant heater with rain shower head, you won't get hot water during rainy day, and warm water during this hot weather.

BTW, some instance water heater will state max working pressure and can't use external pump. This because it won't be powerful enough to heat it.

what model is she using?

if u buy those small rainshower should be still ok.
normally certain water heater models already comes with small rainshower.

but dont expect hotel rainshower quality.

so those come together with water heater should be decent enough?

Yeah, should be decent. I've installed rain shower with no pump heater for my friends, everything is fine, but they have good water pressure in their house and shower head is not big.
But if I were you, I'd save money for a better heater. IMO, small rain shower heads doesn't provide the same quality as bigger ones.

quick question:
1. how do we know the water pressure is good, high enough? any method to gauge ?
2. how big rain shower head is better?

By water pressure meter gauge. The reading is either in PSI or bar commonly.

There is no specific which size is better. Every one have it own satisfied.

1. Guide is here. Normal water pressure is typically between 30 and 80 PSI.

2. The size of a shower head can affect pressure. Larger sizes obviously deliver a larger area of “rain” for your shower, but if you have bad water pressure, a larger size with more nozzles will make the problem worse. When the water pressure is low, the “rain” shower ends up an unsatisfying drizzle. Smaller showerheads with fewer nozzles will have more pressure. But IMO it feels like a regular shower. So you''ll need to check water pressure first. Since my wife asked me to install rain shower for her, I've tried several options before I choose ours. We have 50 PSI (city water) and we're using an average sized showerhead, it feels good. IDK, maybe you'll find something helpful in reviews.
http://www.visionarybaths.com/blog/2016/05...al-shower-heads
https://www.businessinsider.com/best-shower-head
https://wisepick.org/best-rain-showerhead/
https://www.bloomberg.com/news/articles/201...nd-eco-friendly

Feel free to ask me anything if you need

Sorry for bumping this old thread, but I think it's still relevant.

May I know what's the size of your rain shower head based on the 50psi pressure? I'm planning to get a pump at about 3.5 bar which is around your pressure, so now need to size the rain shower head size.

Thanks

p/s - just to add that I'm also looking for similar setup as TS, but with a pump after tank, normal pumpless water heater, then a set of rain shower head + normal shower head with diverter. I understand that the water temperature might not get as hot due to the higher flowrate, but currently I'm only using less than 1/2 of the full scale at the heater, so I guess the temperature should be ok for me.

This post has been edited by lowyat101: Nov 25 2020, 06:22 PM