Only hot water in the shower...

[kallumama]

We moved into our new house a little over a year ago and we just noticed that one of the bathrooms only has hot water coming out through the shower. It starts hot and gets hotter and hotter.

Any idea what is going on?!?!

Thanks,
KalluMama

[Phelps]

Do you have a single handle mixer valve?

Either you have cold water blockage IN the valve or before the valve.

[kallumama]

Yes I do have a single handle mixer valve, but how do i clear this blockage?

thanks!

[pushkins]

1. Has it always been this way ?
2. What if you turn the handle to cold only, what happens ?

[kallumama]

Well since we moved into this house we have never used that shower but once and as far as I remember it did have cold water.

If the lever is turned all the way to cold, still only hot water comes...i tried the lever at all the positions and we only got hot water...

[pushkins]

If the lever is turned all the way to the "cold" setting then the hot water valves should be shut and no hot water should be coming out at all. If the cold line is occluded it would have to be 100% occluded for no cold water at all to come out.

You say that the water starts out warm and then goes hot, to me that seems like it is just hot water pushing through the bathroom lines and is barely warm to start as it is mixing with water not heated in the hot line.
Turn on any hot water only faucet that hasn't been used in a little while and the water will start cool and end hot as I'm sure you know.

My thought at this stage would be that someone has changed the "safety scolding" setting. This is done by taking off the handle and removing and rotating the internal sleeve that is inside the round section protruding from the wall (usually white). This sleeve will need to be removed and turned usually clockwise and reinserted.

One thing I would check and this might be a far stretch is have a look to make sure the shower is being fed with both hot and cold lines (believe it or not I have seen just hot or cold fed to a second, seldom used shower before)

[ABP]

Yeh, sounds like that to me too, someone may have taped into the hot water line for the cold by mistake and now have two hots and no cold. Ive seen this first hand, just because a plumbing company is licensed, that doe's not mean that the employees know what they are doing