How to Choose a Hot Water System

Tap with running water

Nothing ruins your day quicker than an unexpected cold shower. Most people don't think about their hot water units until the day it breaks down. As they only have a lifespan of 7-15 years, it's better to think about it now before it's too late.

Here's a quick start to guide you through the options.


Like For Like

The cheapest option is replacing your hot water system, like for like. If you’ve got a Rheem storage unit you get another Rheem storage unit installed. The advantage of this is that the plumbing connections are normally in about the same spot. Your plumber can just disconnect the old tank, drain it out, wheel the new one in, connect it and fill it, and it should be as easy as that.


Continuous Flow

Continuous Flow

These days people want to replace storage hot water systems with continuous flow units. This is mainly because people don’t ever want to run out of hot water and they are highly efficient. Continuous hot water systems heat the water as it is needed:  You could run the hot water tap 24/7 and it wouldn’t run out! Most new houses will be built with a continuous flow hot water unit. They are also smaller and an efficient option in terms of both gas and cost.

A continuous flow unit allows you to free up space down the side of your house. Some people will change from a storage hot water unit to a continuous flow because they’d rather have something that’s a bit smaller and easy to deal with rather than a big unit in the way, especially if they are building a deck or upgrading their landscaping.

Pro: Only heats the water as it is needed, highly efficient, smaller size

Con: If you are changing from a storage unit to a continuous flow unit, you will likely need to upsize your gasline, which can be a big upfront cost.

Is there a difference between instantaneous and continuous flow?

There is no different between instantaneous and continuous flow hot water units - it's simply a name change due to marketing. Originally these units were called instantaneous, however customers thought this meant the hot water would be 'instant' at the tap, leaving a lot of them annoyed. As a result, these units are now known as continuous flow units, as the water continuously flows through the system. It is worth noting that delivery speed of hot water is not affected by the type of hot water system - it is based on how far away your fixtures are from the hot water unit, your water pressure and the flow rates of the fixtures themselves.


Solar Water Heater

Hot Water Systems Melbourne Plumber

Solar water heating is increasingly popular. There are significant costs upfront for the installation for the different elements - storage tank, solar panel collector - but in the long run, they are the most energy and cost efficient

In the past, we’ve mostly installed solar in new homes. As interest grows and power costs rise there will be increasing numbers of people wanting to change over. Sometimes people think they won’t work well in cold climates but they work just fine because of the booster that tops up the temperature.

Pro: Energy efficient option, and uses a gas or electric booster to keep the temperature where it should be

Con: Significant costs upfront for installation


The Heat Pump

The Heat Pump

Heat pumps draw the heat from the air and heat the hot water and they work even if it the outside air isn’t that warm. We’ve installed these and been impressed with how well they work. They’re maybe not the cheapest to install at the moment, but they are the way of the future because of the move away from fossil fuels.

Pro: Is a green option if you have electric solar panels

Cons: Can come at a higher price point than storage or continuous flow units.



Check out your hot water unit and how old it is. If it’s old, start thinking about getting it replaced. That way you’ll have time to think through your options and make a plan. If you wait for the awful cold shower day it becomes an emergency and you lose the opportunity to make strategic changes that will help your budget in the long term.