Getting Instant hot water from Solar Heater.

Most modern homes have hot water systems for shower or washing.


Why do some homeowners choose solar heater over the instant water heater despite the cost of purchasing the solar heater being 15 to 20 times more than the instant water heater?


The main reason is recurring electricity bills. It costs about RM1.00 of electricity per shower using the instant water heater, whereas the solar heater costs nothing.


A common problem with the solar heater is that it does not provide hot water instantly. We have to drain out the cold water in the pipe (the whole length of the pipe from the solar heater tank to the shower head) before getting the first drop of hot water. Depending on the distance between the solar heater and the shower head, an average of one to three gallons of water is wasted before we get any hot water running for a shower.


The solar water heater also has another shortcoming of low pressure sometimes.


Hence, how do we get the best out of the two water heating systems?


I use a combination of a Microsolar heater and an instant water heater with a built-in jet pump. Of course I have to spend more on the purchase but I get the best of both worlds.


With this arrangement, I have instant hot water using the instant water heater for the first one to two minutes. I then turn down the temperature setting to cold, as I can still get hot water from the solar heater via the mixer. This way, I am able to save more than RM0.90 per shower.


I installed the instant water heater DIY.

Fixing a home instant water heater requires a few basic tools and some basic knowledge of plumbing and electricity.


If you do not have the existing water supply outlet point and the electric power point, you should get a qualified plumber and electrician to fix these two items first. Usually, there is already a tap/shower head outlet in the bathroom. The plumber can tap the connection from here using a T-joint. As for power supply to the heater, there must be a 13 amp power point nearby to tap and extend a 3-pin socket point to the water heater. It is best to leave the electrical wiring job to a qualified electrician.


Tapping and extending a 3-pin socket power point cost about RM150.00 and connecting a T-joint plumbing costs around RM60.00.


With the water and power supply points in place, the charges for installing the water heater unit is RM75.00 per unit. This installation job can be done DIY and you can save the RM75.00 for this one-hour job.


The tools required are an electric drill, a wire stripper, a screw-driver and a test pen.


First, draw a template of the back plate of the water heater to mark the correct position of the screw holes. Stick the template onto the wall where the heater is to be installed. Drill the three screw holes marked on the template. Insert wall plugs into the drilled holes and fasten the heater to the wall firmly. Wall plugs and screw are supplied with the heater.


Get the required length of the three-wire power cable and a three-pin plug. Connect all three wires to the correct poles in the water heater and the plug. The standard red wire is for live point, blue wire for neutral and the green wire is for earth.


Strip 5mm of the insulation from both ends of the three-wire cable for connection to the connector in the heater and the plug.


Connect the hose from the water supply outlet to the heater. Just follow the instructions to connect the hose and shower rose. These items are included in the heater unit.


Plug in the three-pin plug to the socket, turn on the water supply source and switch on the power point. The water heater is ready for use.


The latest range of instant water heaters is equipped with a jet or booster pump to provide adequate water pressure for a nice shower. Some units come with separate switches for pressure pump and heater. So, the choice is yours.


I use the instant water heater with solar heater. I have the best of both worlds as I can turn off either the heater or pressure, depending on the situation. On a cold day, when the solar heater does not provide enough hot water, I turn on the instant water heater. At the start of a shower, I use the instant heater as the water flow from the solar water heater is still cold until the hot water from the storage tank reaches the shower head. After that, I switch off the instant water heater to continue my shower. This way, I save on my electricity bill.