No hot water in hot weather

[TQQ]

On hot days (more than 25 degrees) the hot water runs out. It does not run cold it just runs out. There is no water from the hot taps and the shower has nothing to pump so just stops. It
works for a bit an hour or so later but not for long.The next day it is fine and has no problems at other time. Could the weather be an issue or more likely coincidence?

 

[Masood]

What system have you got? Cold water tank and cylinder I assume, as you mention a shower pump?

 

[Howsie]

I'm intrigued. It doesn't run cold, it runs out. Does that mean it stops?

 

[Masood]

I'm intrigued. It doesn't run cold, it runs out. Does that mean it stops?

I'm wondering, if there's a tank, whether something expands enough in hot weather to make the float valve stick? Intriguing problem!

 

[Howsie]

Running out, rather than going cold leads to believe that the water isn't flowing as it should.

 

[Howsie]

I'm wondering, if there's a tank, whether something expands enough in hot weather to make the float valve stick? Intriguing problem!

Probably a couple of pigeon or squirrel carcasses.... 😉

 

[TQQ]

Yes a cold water tank. And yes the water just runs out!

 

[Howsie]

Sounds like you have the wrong sized CWSC in place or a sticking FOV. Both reasonably cheap to fix!

 

[WaterTight]

weather is a red herring