Using two in my house. Nothing to comment, it perform what it build for, i.e. heating up water. 

There is a breather hole/pipe, this will leak some water out and need to pipe it. If your plumber experience he will know how to do it.

Hmm..not sure original or not, I will check.
Mine is the horizontal type and its placed horizontally if thats what you mean, other than that Im not sure..twice got fried, this last round dry burn or something. I will need to check with the repair guys.

Thanks for bringing up those questions, really appreciate it, will give Rinnai Gas a check 
Talking abt safety, Ive been advised to test the ELCB every month so thats what Ive been doing, just press the test button and if it trips means its working..isnt that enough???

Storage tank no need to wait for it to heat up also cause it will still retain the heat from previous use.
Before you shower just turn it on, when finish then off it. I never wait for it to heat up

Yours is just an assumption.

Instant water heater won't give you real hot water bath when you need it the most (rainy day), not unless you reduce the flow rate and switch to max.

Central water heater don't need to wait 30mins if use every day even alternate days, because after the first use the tank already have balance hot water, and it have some insulation to keep the water for sometime. I have two storage in my house, one I use frequently, another only weekend, or sometime when we are in hurry not wanting to wait for the mater bathroom.  Also if the tank have no more hot water, don't need to wait 30mins before can use, depend on storage size just switch it on for 10 - 15mins and you can take bath.

once it drops below a certain temp it will heat it up again just like those thermo pots

just turn it off after use or turn it off before use if you are kiasi kena electrocuted

Hi All,

Thinking of going for Joven SL30IP instant water heater for my new apartment. Would like to hear your usage experience from anyone who have used this model.

Thanks.

If everyday use, no need wait 30mins, just switch on and use enough. Storage tank can maintain the hot water pretty well. If you didn't use for two days just need wait 10mins.  Unless we are at cold country.

Yours 2500watt, take longer to heat up vs mine 3000watt