Tankless or instant is when you want ease of use and no hacking. It is not ideal for long duration high volume flow esp rain shower but can still work. Built-in pump is optional for condo (usually not necessary) but mandatory for top floor landed.

Tank storage hot water is when two or more bath outlets require centralised hot water. Assumes hot water plumbing already installed otherwise need to hack. Centralised is natural stepping stone to installing other centralised hot water systems like solar hot water or gas as the central hot water plumbing distribution is already there. Here the centralised tank will be relegated to backup heater on continuous rainy days. Pump is required for all top floor bathrooms or where pressure is weak.

This post has been edited by halcyon27: Nov 21 2017, 09:38 AM

I take it that you live in a landed then? The Panasonic models are good..They have been around for a long while. If your looking for a dedicated centralised water pump, refer to this thread. But I strongly don't recommend dedicated centralised pump unless used with centralised heater storage tank. Too many things can go wrong with two separate systems and a pressure reducer will have to be installed before the instant water heater.

Can't control pump means cannot turn it only on when you need it? Means once heater turned on, pump also on?

This post has been edited by halcyon27: Nov 28 2017, 10:43 PM

I see. Some models had optional pump control switch like Alpha / Joven rain shower model. Condos except for the top two floors don't need built in pump. Landed as well top two floor of condos will require. Anyway, here's an old gem of a thread complete with videos by zheilwane. This one too by ozak.

This post has been edited by halcyon27: Nov 29 2017, 10:11 AM

Cause of unit's demise attributed to what? This is condo or landed? If disconnecting the water pipe at the cold inlet, what kind of water comes out in the morning? Could it be that humidity is very high in the shower area? See if mitigating with a wall mounted or glass mounted extractor fan helps before deciding on the next replacement?

This post has been edited by halcyon27: Dec 28 2017, 08:38 AM