Hot Water Problems

No hot water? Check this first.


Continuous Flow Gas Hot Water Heater

Rinnai Infinity Gas Continuous Flow hot water heater.

For continuous flow gas hot water heaters, check that the power lead has not pulled out of the power point and that the power point is switched on.

If it is, check that the power point is working. You can check if a fuse or circuit breaker has tripped in your power board, but the easiest way to check is to plug a small appliance into the power point, such as a hair dryer or power tool.

If you have an indoor temperature controller, (you may not because they are not necessary for this type of heater to work and the majority of installations do not include them), make sure it is turned on. After a power outage or if someone has turned it off, you need to turn the controller back on or the heater won’t ignite.

Finally, check that the gas has not been turned off at the meter. If your other gas appliances such as your cooktop or room heater are working, you can rule that out and it is probably time to contact us. We will be more than happy to help.

Note: If you have just replaced your storage hot water heater with one of these units, or have just installed a new shower
head and find that the temperature in your shower fluctuates between hot and cold, you can check the
water saving disc in the shower head and either replace it with one with a higher flow rate, clean any grit or debris from it or remove it altogether. This type of water heater requires a relatively high flow rate to operate correctly, which is why you can’t have a trickle of hot water like you can with other types of water heater.

Instantaneous Gas Hot Water Heater (Older Style)

Bosch Instantaneous Gas hot water heater.

Before Continuous Flow water heaters, this type of water heater was quite common. Of course, they are still around and the later and current models are quite safe and efficient.

They are very similar to Continuous Flow water heaters but generally don’t operate at quite as high a flow rate and they don’t need to plug in to a power point.

The older models have a pilot light which can go out from time to time. If you are confident, you can follow the lighting
instructions and re-light the pilot.

Some older models are ignited by replaceable batteries when a hot tap is turned on. If you have one of these, find and replace the batteries.

The later Bosch models generate power by the cold water running through a Hydro Generator when a hot tap is turned on. It can generate enough power to ignite the water heater and status lights, etc.
If you have one of these and it won’t light, there is not much you can do but call a professional, like SB Plumbing Services.

Electric Storage Hot Water Heater

Rheem Mains Pressure Electric water heater.

There aren’t really any tips to get you out of trouble if you have one of these water heaters and it is not heating, other than the following.

If your system is connected to an Off-Peak circuit, the hot water fuse or circuit breaker in your power board hasn’t blown and there are no leaks at your water heater, there is a possibility that the Off-Peak relay didn’t kick in at the set time. You could call your energy provider and arrange for them to check the relay for you. This is generally free of charge and they come the same day. The only problem with this is that if there is nothing wrong with the relay, you will have wasted some time and it may be too late to get a plumber there that day.

If the hot water fuse or circuit breaker in your power board has blown or tripped, it’s likely that a fault of some description has caused it, such as a bad thermostat or element. When this occurs, the safe thing to do is to get it checked by a licenced plumber with the relevant Disconnect/Reconnect Fixed Electrical Equipment qualification. Depending on the age of the cylinder, valves, thermostats and elements can be replaced easily.

These tips also apply to heat pumps and instantaneous electrical heaters.

Please do not open the thermostat cover and do take care inside your power board. If in any doubt, please call us.

Gas Storage Hot Water Heater 

Rheem Mains Pressure External Gas hot water heater.

If you have this type of water heater, sometimes the pilot light goes out, especially in high wind or during a storm.

Simply follow the lighting instructions, which are on a label inside the burner cover lid or on the tank if it’s an indoor model, to light the pilot.

If the piezo igniter doesn’t spark, just use a long taper or a BBQ lighter. Once the pilot light has ignited and you’ve held the control knob down for at least 30 seconds, it should stay lit once you release the knob. If not, try again as many times as you like, with a few minutes in between attempts, and if the pilot does not stay lit, the thermocouple safety device needs to be replaced and the main burner will not light until this is done.

Please do not keep holding the control knob down for too long if the piezo igniter is not sparking because if it finally does generate a spark, this accumulated gas could then ignite and cause a small explosion serious enough to burn hair and skin and cause damage to the heater

If in any doubt, please call us. 

 If you have any other trouble and there is nothing obviously wrong with your hot water system, give us a call and we can offer advice.

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