The Shower Doctor Surgery: How to replace a PRD on a Ga

A PRD - or pressure relief device - is a safety gadget that is designed to prevent pressure from building up within a shower's heating tank due to a blockage in the shower head or hose.

If yours has blown, you may be able to fix it by pushing the small ball at the back of the device back in, but be aware that this is very much a temporary solution and you will most certainly need to replace the old PRD with a new one.

The video that accompanies this how-to guide shows a Gainsborough 8.5 SDL shower, but while other showers in this range may look slightly different on the outside, they are all identical inside. So you'll still find this information useful if you have another model of Gainsborough SDL.

What you need

  • A positive screwdriver with a #0 point
  • A cloth or towel, which you should place over the plug hole in your shower tray or bath to make sure you don't lose any screws
  • Your new PRD - either a long or a short version depending on your model of shower

Removing the PRD

Using your screwdriver, take the cover off the shower unit. You'll find the main screw behind the Gainsborough badge, which should just pull off.

Set the temperature controller to the 12 o'clock position and it should also pull off fairly easily. You'll then find another screw underneath the unit.

The PRD itself is held in with another two screws. It can be a fiddly job getting to the back screw, but you should be able to manage without taking the shower unit off the wall.

As you will see in our video guide, we remove the unit simply to show you where the screws are located. It's unlikely you'll have to do this.

Next, unscrew the screws and pull out the old PRD

Fitting the new PRD

Your new PRD should simply push into place and you'll be able to fix it in by replacing the two screws.

You should then replace the cover of the shower unit, again by replacing the screws you removed earlier. Your new PRD should now be functional.

If you need any assistance in identifying your model of Gainsborough SDL shower or selecting the right PRD for your repair, then get in touch and we'll be happy to help.

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