You turn the hot tap on, expecting the usual few seconds of cold before it warms up … except this time it doesn’t. This time, you get no hot water at all. So you wait a bit longer, thinking it’s just being slow today … and it stays cold. At that point, you’re standing there wondering why do I have no hot water – and is it something small that isn’t going to ruin your day, or something you definitely need to call someone about?
We’ve all been there, right? Mercifully, some of the time the cause is more straightforward than it feels in the moment. so before you assume the worst or start pricing up a whole new system, here are the things worth actually checking first.
Hot water system troubleshooting: Things to check first
No hot water in house? Before panicking or immediately dialling the number of your favourite local plumber, take a couple of minutes and run through our numbered steps here. You never know, you could be back to steaming hot water before you know it.
1. Is it one tap or the whole house?
Start by checking a few different taps, not just the one you noticed it at first. If you really do have no hot water coming from taps throughout the entire house, you can be pretty sure it’s a hot water system problem.
But if it’s isolated to one tap – like just no hot water in shower specifically – that’s more likely a local issue with that fixture. Could be a mixer valve or a blocked isolation valve, and not the hot water system failing entirely.
The answer to this step alone can save you a fair bit of guesswork later on.
2. Check whether water’s flowing at all
There’s also a real difference between water that’s simply not heating up and when there really is no water coming out of hot tap fixtures at all.
If the hot tap runs completely dry or barely trickles, check the isolation valve near that tap or fixture hasn’t been accidentally closed. It may have been fiddled with during other work in the house or a recent renovation. That would be a nice easy fix.
3. Check the power or gas supply
For electric hot water systems, check the switch at the wall or the circuit breaker hasn’t tripped. And for gas hot water systems, check the gas isolation valve is open. If your gas unit is getting older, also check that the pilot light hasn’t gone out.
4. Look for a tripped safety switch
If the power switch looks fine but nothing’s happening, check your switchboard for a tripped circuit breaker or safety switch.
Hot water systems draw a fair bit of power, and they’re not unusual candidates for tripping a circuit if something’s starting to fault.
5. Check if you’re on an off-peak system
Some electric hot water systems only heat during set off-peak hours – usually overnight. If yours runs on this kind of tariff and something’s changed the timing, or there’s been a longer-than-usual high demand period in the house, you can fairly easily run the tank down before its next scheduled heating window.
6. Check the thermostat setting
On most electric storage systems, the thermostat sits inside the tank casing behind a screwed access panel – so it’s not something you’d casually bump. It could be that the thermostat was never set correctly from the start, or it’s starting to fail.
Older units sometimes have a visible external dial that can get adjusted by accident, but on newer systems a thermostat that’s drifted or failed internally is the more likely cause of water that’s cold or barely warm while everything else seems to be working fine.
7. Check for low pressure alongside the cold water
If you’re getting some hot water but it’s weak, that’s a different problem to having no hot water at all.
No hot water pressure issues usually point to:
- A partially blocked pipe
- A fault with the pressure limiting valve
- Sediment build-up inside the tank itself narrowing the flow.
8. Look for leaks or unusual noises
Any of this sound familiar?
- Tank leaking?
- Pressure relief valve dripping?
- Banging or popping sounds?
We hate to say it, but these are all signs of a bigger underlying issue rather than a simple reset. If you’re noticing any of these alongside the cold water, it’s worth getting it looked at rather than continuing to troubleshoot on your own, since some of these faults can get worse quickly if left unattended.
When it’s time to call someone
If you’ve worked through all of that and you’re still wondering why is there no hot water in my house, it’s a fair sign the issue is inside the system itself rather than something you can fix from the outside.
Could be:
- A failed heating element
- A faulty thermosta
- A gas control fault
- A tank that’s simply reached the end of its working life.
Get in touch with S&J Plumbing and Gasfitting
Our licensed plumbers deal with hot water faults across Brisbane Northside, Brisbane Southside, Moreton Bay, Logan, Redland Bay, and Ipswich every day, from a quick fix to a full system replacement. If you’ve checked the basics and you’re still without hot water, get in touch with S&J Plumbing and Gasfitting and we’ll get it diagnosed and sorted properly, with same-day service available when you need it.