Signs something's wrong
- Stains, swelling or soft spots on walls or floors next to the shower.
- The shower head or mixer drips after it's off.
- Cracked grout or sealant, or tiles that move.
- Flow that has dropped, or hot that's weaker than cold.
- Temperature that swings, or runs hotter than it used to.
- Water draining slowly: see blocked shower drains.
A leaking shower: plumbing or waterproofing?
Water escaping from a shower can come from the plumbing (the mixer, the pipes behind the wall, or the waste and trap) or from the linings and seals around it. A plumber can test the pipework and the waste and tell you which.
If the fault is in the waterproofing or tiling, that part of the fix is usually for another trade. Stop using a shower that's leaking into the wall; the damage you can't see grows faster than the stain you can.
Weak flow
With low pressure hot water, a gentler shower is built in. Low pressure copper cylinders are made for working pressures of no more than 120 kPa (12 m head). Rheem describes mains pressure as hot and cold arriving at the same pressure, straight from the street's water main.
Other causes include a clogged shower head, a mixer that doesn't suit your pressure, a valve that's partly closed, or a fault on the network. Our water pressure page goes through them. Whether your house could move to mains pressure is a plumber's call after a look: see converting to mains pressure.
Temperature that won't behave
Hot water at showers has to be delivered at a temperature that avoids the likelihood of scalding: that's in the Building Code. Tempering valves are made to prevent scalding in homes, and a tired one can leave the shower too hot, too cool or wandering between the two.
Don't change the cylinder thermostat to fix a shower. The water in the cylinder needs to be hot enough to control Legionella, then tempered to a safe temperature at showers and basins. A plumber should look at the tempering valve and the mixer instead.
What a plumber will do
A plumber will check the mixer cartridge and valves, measure the flow and pressure, test the pipes in the wall if a leak is suspected, and look at the waste and trap. From there it's a repair, a new mixer, or a new shower.
What you can and can't do
You can
- Repair or replace the shower taps, washers or plug, which are on PGDB's homeowner list.
- Clear hair and soap from the waste grate.
- Stop using a shower that's leaking into the wall, and photograph the damage.
Leave to an authorised tradie
- Replacing or moving a mixer set into the wall.
- The pipes, the trap and the waste.
- Tempering valve faults.
- A new shower, or turning a bath into a shower.
When a shower job needs paperwork
Fitting or removing a shower and its pipes is sanitary plumbing, which needs an authorised person. Swapping a shower for a comparable one in the same spot needs no building consent when an authorised plumber does it. Putting in an extra shower adds a sanitary fixture, so the exemption for altering existing plumbing won't cover it, and you should ask your council about consent first.
PGDB also points out that you might need to tell your insurer about renovations to stay within your policy.
What we would do
Work out which of the three problems you have before booking: leak, flow or temperature. If water is getting into the wall, stop using the shower now and get it looked at, because that's the one that gets expensive quietly. For weak flow, find out whether your hot water is low pressure before buying a new shower head. Then tell us what's happening and we'll match you with an authorised plumber who handles shower repairs.