Dodgy water heater

[mcfish]

I have a fagor under the sink water heater. When I had it installed ten years ago I couldn't get it to go a warm temperature it either went hot or cold. The guy who installed it said to get a larger diameter shower head and I did and it worked

 

Now Im back to square one again, either to hot or to cold. With the shower head off I can set any temperature I want 

 

Do I go buy another bigger shower head ? I was gonna call a plumber but the unit delivers hot water at descent pressure just not with the shower head on it 

Edited September 23, 2016 by mcfish

[Crossy]

Shower head bunged up?

 

Soak it in vinegar for a few hours :)

[bankruatsteve]

Or the "toilet duck".  After, use a toothpick to go through all the holes.  Does wonders for a dodgy shower head.

[mcfish]

Thanks guys sounds like logical and cheap solutions. Probably a big build of gunk in there over a long period