My hot shower goes cold

[billy_boy51]

This my first summer in the house, and I've discovered a problem with my shower. I run the hot water first to bring it up to temperature, and then when I turn on the cold water the shower goes cold after a few seconds. After turning off the cold water, it takes some time for the hot to return. It's like the cold is actually forcing it's way down the hot water pipes. I thought it may be the demand gas heater, but the problem seems to be only with the shower. I've installed new tap washers to no avail. Any one with a suggestion?

[Ron Dunn]

What flow rate is your water heater? (ie, 9l/min, 25l/min)

I think your heater is being temporarily starved of water, meaning that it cuts out and has to restart. This can happen if the flow rate is too low, or if the incoming pressure to the heater is inconsistent.

[ratchet]

This happened to me

took the water saver washer out at the shower

no more problems

except water consumption

something to do with minimum water flow through unit and gas shuts off ,

I think

[bricks]

This is happening because - as was suggested before- you have a low flow heater and a water saver shower head.

Unscrew your shower head anti-clockwise, you should see a small washer in the back of the shower head, rip it out with a screw driver, replace shower head.

Water savers are not required on low flow heaters as you already by default are water saving.

Cheers.

[Dirty Doogie]

It might also be your tempering valve if you have one fitted. Identical problems occurred to me after installing a new bathroom and fitting one of these clunkers.

[billy_boy51]

Thanks for all the suggestions guys. Bricks got it right though, I liked his logic, realising that the lack of flow in the hot pipes caused by a restrictor, could stop the heating. I looked, and there it was, a sneaky little restrictor. Once removed, all is well with the world again, as my wife can now enjoy her showers again.
Cheers Guys