The failing of a shower's pressure relief device (known for short as PRD) is a common fault you are likely to encounter when something goes wrong with your unit, so knowing how to replace this component can save you not only time but a lot of money too!
What usually causes it to blow is the head becoming blocked or if an element breaks, as this can create a buildup of pressure in the heating tank, which then has a similar effect on the PRD.
To carry out this work, you will need:
As with when you carry out any maintenance work on your shower, the first thing you should always do is ensure it is isolated from the electrical mains. Turn the unit off using the pull cord and follow this up with shutting it off from the fuseboard. The best advice here is to remove the circuit breaker and put it in your pocket. This way, there's no chance of someone putting it back in while you're working in the bathroom and reactivating it while it is exposed.
Next, you need to remove the shower's cover. Most showers have two screws at the top of the casing and one at the bottom that you need to remove to do this.
Identifying and removing the PRD
On the Triton T80Z, you will find the PRD at the bottom of the shower, on the back of the outlet pipe. This is similar to many modern Triton showers, although older models have the PRD mounted on the front of the pipe. As a result newer models are generally harder to repair, as the process involves removing the outlet pipe to access the device.
First, remove the shower hose and then unscrew the outlet pipe itself, which is a fairly straightforward procedure. When you've taken out the screws, give it a quick twist and pull to remove it, and you'll find the PRD is a different-coloured piece of plastic attached to the outlet pipe with two more screws.
When you've separated it from the pipe, you need to look inside the PRD for a black ball. If it's there, the device should be ok, but if it's disappeared, the ball will have been blasted when the PRD blew. If you can find the ball (it is quite small!), then as a temporary measure you can push it back into place. However, the whole device will still need to be replaced as once it's been blown out it will never operate in the same capacity as it did previously.
Replacing the PRD
Now you've established whether or not the problem is the PRD, you can swap it with a new device if necessary. Make sure your replacement part comes with an O-ring, which should be placed on the PRD and refitted to the outlet pipe. Press it into place and screw it back onto the outlet pipe.
You also need to remember to ensure the outlet pipe's O-ring is in the correct position when reattaching it to the main unit, as otherwise it won't seal. Simply reverse the steps you took to remove the pipe to put it back on, before re-fitting the hose, screwing it tightly and reapplying the cover.
Finally, set the temperature of your shower to cold before you run it for the first time after doing your work. This is so you can allow for the heating tank to fill up again before turning up the heat - ensuring you don't damage the elements.
Once this has been done, you're finished! If you'd like to watch a video version of this guide, check it out below: