Thread: Who knows stuff about electric hot water services?

Here's a photo of the information on the unit (and some of the spiders).
hot water heater label.jpg

There's no water dripping from the relief valve now that I have disconnected the pipe. I had a feel of it before I disconnected it, it was warm at the top near the valve but the warmth didn't extend down the pipe very far.

Damien, by a 'split element', do you mean that this is a fault that has occurred, as in 'looks like your element has split', or that the element is a split system and one part has failed?

Originally Posted by Old Farang

Where is the thermostat, and are you sure it is working correctly?

I think the thermostat is located behind the cover near the bottom where the element is accessed, I'm not really sure. Would a faulty thermostat cause this problem?

While I'm sure it's not want you want to hear, 20 years out of a unit like that is damn good going.

Split element - 2 x 3000 watt elements in parallel to make up the 6000 watts this unit is. You may have dropped one element. Data plate says lower heater 6000 watts, but I would still think it would be 2 x 3000 watt units down there.

Not really relevant to this symptom, but I had dodgy hot water when I moved into the new place back in december.
1) I called the electricity provider to confirm that the off peak relay was working correctly (or you can visually check it when it flicks over in the wee hours of the morning)
2) You can isolate power to the unit and test the continuity and resistance of the element with a multimeter. I'm not sure what value you'd be looking for, but the higher resistance means that it will heat up when power is supplied... Open loop (ie one pole of the element is not electrically connected to the other)- means that it's FUBAR. Elements can be replaced in some units, but YMMV.
3) I found that the wiring to the element was corroded and only hanging on by a few strands. Resoldered it on, and all was good again.
4) I threw a new thermostat in it, just to be sure. About 25 bucks from Reece plumbing, upon supplying make and model of the unit.

I dare-say, having a weak or corroded connection at the element could be a cause of a poor performing element, and hence lower temp hot water. Worth some thought.

Pod - does it heat up if you put the flick the booster onto day mode?

Got a pic of the whole unit?
Can you remove the covers and get a pic?
Split, as in has a split in it. But just realised you said its 6kw

Thanks again for all the help fellas, I'll investigate more tomorrow in the daylight, I'll pull the cover off the element and check for corroded wires, isolate it and check for continuity across the element(s). Funny thing is it seems better today- I'm wondering if perhaps the valve had been leaking hot water out into the under-slab drain and it has seated properly after I cycled it a few times yesterday. We all got a hot shower today; mind you, we've all been extra quick these past few days. Might have to give it a bit of a challenge tomorrow.

The OP has posted that it is a 6,000 watt 400 litre storage type heater, and it runs on an off peak control. If one leg of a split element is open circuit it is going to take a bit over twice as long to heat up a tank from cold, or recover after use. The off peak control will be set on the basis of 6,000 watts, and it will not be switched on long enough to recover the full quantity of the tank. OR, the thermostat is cactus. I also agree that 20 years service is way beyond a reasonable expectation.