No hot water, and most of the time it is not the plumbing
Worth saying before you ring anybody. Most no-heat faults on an instant electric heater are electrical. One common cause is ours, and it is the one that gets working heaters thrown out.
The guides you will find are describing a different machine
Search this and you get manufacturers and American repair sites explaining burners, pilot lights, orifices and anode rods. Those belong to a large gas or electric storage tank, which is the normal fixture in the United States and uncommon in a home here.
If yours is the instant electric heater on the bathroom wall, none of that applies. There is no burner, no pilot, no anode rod and no tank to drain.
Where the line is
Electrical, and not ours
- The unit is completely dead with no lights
- The breaker or the ELCB trips when it is switched on
- It trips again after one reset
- Any burning smell, discolouration around the unit, or a warm socket
- A heating element or thermal cutout that needs replacing
An electrician or the manufacturer service centre. A heater that keeps tripping an earth-leakage breaker is not a nuisance to work around; it is the breaker doing its job.
Water side, and worth us looking
- The unit has power but never fires, and the flow through it is weak
- Hot water at one outlet and not another
- Pressure dropped recently and the heater stopped working at the same time
- A leak at the inlet or outlet pipework rather than at the unit body
- Scale in the supply line feeding it
These are plumbing faults that present as a broken heater, and the flow switch one is the reason working heaters get replaced.
The one that gets working heaters replaced
An instant heater does not switch on when you flip a switch. It fires when enough water moves through it to close a flow switch inside. That is a safety feature: it stops the element heating with no water around it.
So if your flow has weakened, from a scaled-up shower head, a valve left partly closed, a tank sitting too low or a pump on its way out, the heater will appear completely dead while being in perfect working order. People buy a new one, fit it, and find it does the same thing.
Before replacing any instant heater: clean the shower head, open every valve fully, and see whether it fires. It costs an evening and it is free.
What we will and will not do
We will look at the water side: the supply feeding it, the pressure and flow reaching it, scale in the line, and the pipework at the inlet and outlet. We install and repair heaters, which is on our service list.
We will not rewire a heater, replace an element, or work on a unit that is tripping an earth-leakage breaker. That is an electrician's work and we will tell you so rather than take the visit.
Questions about a heater that will not heat
- My instant shower heater will not switch on at all. Is that plumbing?
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Usually not. On an instant electric heater a dead unit is nearly always electrical: the supply, the ELCB or breaker, the thermal cutout or the element itself. Check whether the ELCB on the unit or the breaker in the panel has tripped, and reset it once. If it trips again, stop, leave it off, and get an electrician or the manufacturer service centre. A heater that repeatedly trips an earth-leakage breaker is telling you current is finding its way somewhere it should not, and that is not something to keep resetting.
- The heater has power but the water stays cold. What is the plumbing cause?
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The one worth checking before anything is replaced: flow. An instant heater has a flow switch and will not fire until enough water is moving through it. If your pressure has dropped, from a blocked shower head, a partly closed valve, a low tank or a failing pump, the unit will look completely dead while being perfectly healthy. Clean the shower head and open every valve fully, then try again.
- Why do the guides I find talk about burners and anode rods?
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Because they are American and they are describing a large gas or electric storage tank, which is the normal fixture there and uncommon in a Filipino home. If you have an instant heater on the bathroom wall, none of that applies to you: there is no burner, no pilot, no anode rod and no tank to drain.
- It heats, but only barely, and it used to be better.
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Scale, most likely, on the element or inside the heat exchanger. Hard water leaves a deposit that insulates the element from the water it is meant to be heating, so the unit draws the same power and delivers less heat. On a storage unit the element can often be cleaned or replaced; on a sealed instant unit it is usually a service-centre job.
Power but no heat?
Check the flow before you buy anything. If it is still dead with good flow, ring us and we will tell you whose job it is.
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